timers

[Emanuel Rumpf-2]

Hi

I'm confused about all the timers.

There is:
- system timer
- hpet (high precision event timer)
- hr-timer (high resolution timer)
- rtc (real time clock)
- cyclic (what's that? a coded loop?)
- anything else ?


What is the relation of all these ?
Which hardware devices are actually used by those ?
Which is the prefered timer for sequencing ? hr-timer / rtc ?

Some timers can be opened only once ?
For example if jackdbus is using hr-timer, no other application can too ?
But applications need to use the same timer  in order to sync - right ?
Which concepts exist to share a certain timer ?
How to verify if a timer is working ?
Is there tool that would help ?
Opening the hr-timer with rosegarden freezes my whole system here,
what could cause that ?

Thanks



Related to my sytem:


I get:
------

$ lsmod | grep rtc
rtc_cmos                9680  0
rtc_core               16784  1 rtc_cmos
rtc_lib                 2844  1 rtc_core



But the following command doesn't list any rtc-timer (is that
expected, what to do ?):
-------------------------------------------------------------
$ cat /proc/asound/timers
G0: system timer : 1000.000us (10000000 ticks)
G3: HR timer : 0.001us (1000000000 ticks)
  Client sequencer queue 2 : running
  Client sequencer queue 0 : running
P0-0-0: PCM playback 0-0-0 : SLAVE
P0-0-1: PCM capture 0-0-1 : SLAVE
P0-1-0: PCM playback 0-1-0 : SLAVE
P0-2-1: PCM capture 0-2-1 : SLAVE
P1-3-0: PCM playback 1-3-0 : SLAVE
P2-0-0: PCM playback 2-0-0 : SLAVE
P2-0-1: PCM capture 2-0-1 : SLAVE
P5-0-1: PCM capture 5-0-1 : SLAVE

$ ls /dev/rtc* -lh
lrwxrwxrwx 1 root root       4 2009-11-05 17:13 /dev/rtc -> rtc0
crw-rw---- 1 root audio 251, 0 2009-11-05 17:13 /dev/rtc0

$ uname -a
Linux 2.6.31-rt11-e1 #1 SMP PREEMPT RT  Oct 27 CET 2009 i686 GNU/Linux Debian



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[Ralf Mardorf]

Emanuel Rumpf wrote:

> Hi
>
> I'm confused about all the timers.
>
> There is:
> - system timer
> - hpet (high precision event timer)
> - hr-timer (high resolution timer)
> - rtc (real time clock)
> - cyclic (what's that? a coded loop?)
> - anything else ?
>
>
> What is the relation of all these ?
> Which hardware devices are actually used by those ?
> Which is the prefered timer for sequencing ? hr-timer / rtc ?
>  

If hardware is fine with Linux real-time audio, if I understand
correctly, the preferred timer for MIDI sequencers is (should be) system
timer at ! 1000 Hz ! For my hardware, that has got problems with
real-time audio, it's PCM playback and PCM capture. Using this timers
MIDI jitter will decrease a little bit.

This is the output I get for 64 Studio 3.0-beta3:

spinymouse-sudo@64studio:~$ cat /proc/asound/timers
G0: system timer : 1000.000us (10000000 ticks)
P0-0-0: PCM playback 0-0-0 : SLAVE
P0-0-1: PCM capture 0-0-1 : SLAVE
  Client sequencer queue 0 : stopped
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[James Warden]

Hi guys,

Here is what I have:


$ cat /proc/asound/timers
G0: system timer : 1000.000us (10000000 ticks)
G3: HR timer : 0.001us (1000000000 ticks)
  Client sequencer queue 0 : running
P1-0-0: PCM playback 1-0-0 : SLAVE
P1-0-1: PCM capture 1-0-1 : SLAVE

Ralf, you do not benefit from a high res timer. See how much more precise the HR timer is from the output above. Check which snd timer you have loaded:

$ lsmod | grep timer

snd_hrtimer             2148  1
snd_timer              17408  3 snd_hrtimer,snd_seq,snd_pcm

Of course, your h/w should have a HR timer:

$ ll /dev/hpet
crw-rw---- 1 root audio 10, 228 2009-11-05 12:59 /dev/hpet

you can specify the clock source to jackd:

$ jackd --help
...
[ --clocksource OR -c [ c(ycle) | h(pet) | s(ystem) ]
...



J.


--- On Sat, 11/7/09, Ralf Mardorf <ralf.mardorf@...> wrote:

> From: Ralf Mardorf <ralf.mardorf@...>
> Subject: Re: [LAD] timers
> To: "Emanuel Rumpf" <xbran@...>
> Cc: linux-audio-dev@...
> Date: Saturday, November 7, 2009, 7:04 AM
> Emanuel Rumpf wrote:
> > Hi
> >
> > I'm confused about all the timers.
> >
> > There is:
> > - system timer
> > - hpet (high precision event timer)
> > - hr-timer (high resolution timer)
> > - rtc (real time clock)
> > - cyclic (what's that? a coded loop?)
> > - anything else ?
> >
> >
> > What is the relation of all these ?
> > Which hardware devices are actually used by those ?
> > Which is the prefered timer for sequencing ? hr-timer
> / rtc ?
> >   
>
> If hardware is fine with Linux real-time audio, if I
> understand
> correctly, the preferred timer for MIDI sequencers is
> (should be) system
> timer at ! 1000 Hz ! For my hardware, that has got problems
> with
> real-time audio, it's PCM playback and PCM capture. Using
> this timers
> MIDI jitter will decrease a little bit.
>
> This is the output I get for 64 Studio 3.0-beta3:
>
> spinymouse-sudo@64studio:~$ cat /proc/asound/timers
> G0: system timer : 1000.000us (10000000 ticks)
> P0-0-0: PCM playback 0-0-0 : SLAVE
> P0-0-1: PCM capture 0-0-1 : SLAVE
>   Client sequencer queue 0 : stopped
> _______________________________________________
> Linux-audio-dev mailing list
> Linux-audio-dev@...
> http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
>

     
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[James Warden]

I forgot to add that snd_hrtimer is used by jackd.
If I turn jackd off, the snd_hrtimer module is not used:

$ lsmod | grep timer
snd_hrtimer             2148  0 ## <<< not used
snd_timer              17408  3 snd_hrtimer,snd_seq,snd_pcm

J.

--- On Sat, 11/7/09, James Warden <warjamy@...> wrote:

> From: James Warden <warjamy@...>
> Subject: Re: [LAD] timers
> To: "Emanuel Rumpf" <xbran@...>, "Ralf Mardorf" <ralf.mardorf@...>
> Cc: linux-audio-dev@...
> Date: Saturday, November 7, 2009, 7:34 AM
> Hi guys,
>
> Here is what I have:
>
>
> $ cat /proc/asound/timers
> G0: system timer : 1000.000us (10000000 ticks)
> G3: HR timer : 0.001us (1000000000 ticks)
>   Client sequencer queue 0 : running
> P1-0-0: PCM playback 1-0-0 : SLAVE
> P1-0-1: PCM capture 1-0-1 : SLAVE
>
> Ralf, you do not benefit from a high res timer. See how
> much more precise the HR timer is from the output above.
> Check which snd timer you have loaded:
>
> $ lsmod | grep timer
>
> snd_hrtimer         
>    2148  1
> snd_timer             
> 17408  3 snd_hrtimer,snd_seq,snd_pcm
>
> Of course, your h/w should have a HR timer:
>
> $ ll /dev/hpet
> crw-rw---- 1 root audio 10, 228 2009-11-05 12:59 /dev/hpet
>
> you can specify the clock source to jackd:
>
> $ jackd --help
> ...
> [ --clocksource OR -c [ c(ycle) | h(pet) | s(ystem) ]
> ...
>
>
>
> J.
>
>
> --- On Sat, 11/7/09, Ralf Mardorf <ralf.mardorf@...>
> wrote:
>
> > From: Ralf Mardorf <ralf.mardorf@...>
> > Subject: Re: [LAD] timers
> > To: "Emanuel Rumpf" <xbran@...>
> > Cc: linux-audio-dev@...
> > Date: Saturday, November 7, 2009, 7:04 AM
> > Emanuel Rumpf wrote:
> > > Hi
> > >
> > > I'm confused about all the timers.
> > >
> > > There is:
> > > - system timer
> > > - hpet (high precision event timer)
> > > - hr-timer (high resolution timer)
> > > - rtc (real time clock)
> > > - cyclic (what's that? a coded loop?)
> > > - anything else ?
> > >
> > >
> > > What is the relation of all these ?
> > > Which hardware devices are actually used by those
> ?
> > > Which is the prefered timer for sequencing ?
> hr-timer
> > / rtc ?
> > >   
> >
> > If hardware is fine with Linux real-time audio, if I
> > understand
> > correctly, the preferred timer for MIDI sequencers is
> > (should be) system
> > timer at ! 1000 Hz ! For my hardware, that has got
> problems
> > with
> > real-time audio, it's PCM playback and PCM capture.
> Using
> > this timers
> > MIDI jitter will decrease a little bit.
> >
> > This is the output I get for 64 Studio 3.0-beta3:
> >
> > spinymouse-sudo@64studio:~$ cat /proc/asound/timers
> > G0: system timer : 1000.000us (10000000 ticks)
> > P0-0-0: PCM playback 0-0-0 : SLAVE
> > P0-0-1: PCM capture 0-0-1 : SLAVE
> >   Client sequencer queue 0 : stopped
> > _______________________________________________
> > Linux-audio-dev mailing list
> > Linux-audio-dev@...
> > http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
> >
>
>
>      
> _______________________________________________
> Linux-audio-dev mailing list
> Linux-audio-dev@...
> http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
>

     
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Linux-audio-dev@...
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[Ralf Mardorf]

Thank you Emanuel for this thread :)
thank you James for the information :)

hopefully this might narrow down my trouble with MIDI jitter for
external equipment, OTOH I don't have any MIDI jitter for MIDI internal
Linux. ALSA MIDI and JACK MIDI seems to be fine what ever timer I use,
this means there is absolutely no jitter when using a Linux sequencer to
control a Linux synth. Jitter only occurs when using my USB MIDInterface
to control external MIDI equipment. Unfortunately I can't get my
Envy24's MPU working.

There seems to be no hrtimer available yet:

$ lsmod | grep snd_hrtimer
$ lsmod | grep timer
snd_timer              22024  2 snd_pcm,snd_seq
snd                    63800  21
snd_ice1712,snd_ak4xxx_adda,snd_cs8427,snd_ac97_codec,snd_i2c,snd_mpu401_uart,snd_usb_audio,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_hwdep,snd_seq_oss,snd_rawmidi,snd_seq,snd_timer,snd_seq_device
$ uname -a
Linux 64studio 2.6.29-1-multimedia-amd64 #1 SMP PREEMPT RT Thu Feb 26
16:18:05 UTC 2009 x86_64 GNU/Linux

Before I start googleing. Is this a feature for 2.6.31 only? I'm still
not able to boot the .31 kernel-rt from the Suse 11.2 RC repository and
compiling for Suse also failed, but in the past I never had trouble to
build kernel-rt for Debian/ Ubuntu based 64 Studio. Maybe I should try
to build a kernel .31 for 64 Studio? Or is it just a module I need to
add? Or is my hardware missing something?

Going to use Google now.

Bye,
Ralf

James Warden wrote:

> I forgot to add that snd_hrtimer is used by jackd.
> If I turn jackd off, the snd_hrtimer module is not used:
>
> $ lsmod | grep timer
> snd_hrtimer             2148  0 ## <<< not used
> snd_timer              17408  3 snd_hrtimer,snd_seq,snd_pcm
>
> J.
>
> --- On Sat, 11/7/09, James Warden <warjamy@...> wrote:
>
>  
>> From: James Warden <warjamy@...>
>> Subject: Re: [LAD] timers
>> To: "Emanuel Rumpf" <xbran@...>, "Ralf Mardorf" <ralf.mardorf@...>
>> Cc: linux-audio-dev@...
>> Date: Saturday, November 7, 2009, 7:34 AM
>> Hi guys,
>>
>> Here is what I have:
>>
>>
>> $ cat /proc/asound/timers
>> G0: system timer : 1000.000us (10000000 ticks)
>> G3: HR timer : 0.001us (1000000000 ticks)
>>   Client sequencer queue 0 : running
>> P1-0-0: PCM playback 1-0-0 : SLAVE
>> P1-0-1: PCM capture 1-0-1 : SLAVE
>>
>> Ralf, you do not benefit from a high res timer. See how
>> much more precise the HR timer is from the output above.
>> Check which snd timer you have loaded:
>>
>> $ lsmod | grep timer
>>
>> snd_hrtimer        
>>    2148  1
>> snd_timer            
>> 17408  3 snd_hrtimer,snd_seq,snd_pcm
>>
>> Of course, your h/w should have a HR timer:
>>
>> $ ll /dev/hpet
>> crw-rw---- 1 root audio 10, 228 2009-11-05 12:59 /dev/hpet
>>
>> you can specify the clock source to jackd:
>>
>> $ jackd --help
>> ...
>> [ --clocksource OR -c [ c(ycle) | h(pet) | s(ystem) ]
>> ...
>>
>>
>>
>> J.
>>
>>
>> --- On Sat, 11/7/09, Ralf Mardorf <ralf.mardorf@...>
>> wrote:
>>
>>    
>>> From: Ralf Mardorf <ralf.mardorf@...>
>>> Subject: Re: [LAD] timers
>>> To: "Emanuel Rumpf" <xbran@...>
>>> Cc: linux-audio-dev@...
>>> Date: Saturday, November 7, 2009, 7:04 AM
>>> Emanuel Rumpf wrote:
>>>      
>>>> Hi
>>>>
>>>> I'm confused about all the timers.
>>>>
>>>> There is:
>>>> - system timer
>>>> - hpet (high precision event timer)
>>>> - hr-timer (high resolution timer)
>>>> - rtc (real time clock)
>>>> - cyclic (what's that? a coded loop?)
>>>> - anything else ?
>>>>
>>>>
>>>> What is the relation of all these ?
>>>> Which hardware devices are actually used by those
>>>>        
>> ?
>>    
>>>> Which is the prefered timer for sequencing ?
>>>>        
>> hr-timer
>>    
>>> / rtc ?
>>>      
>>>>    
>>>>        
>>> If hardware is fine with Linux real-time audio, if I
>>> understand
>>> correctly, the preferred timer for MIDI sequencers is
>>> (should be) system
>>> timer at ! 1000 Hz ! For my hardware, that has got
>>>      
>> problems
>>    
>>> with
>>> real-time audio, it's PCM playback and PCM capture.
>>>      
>> Using
>>    
>>> this timers
>>> MIDI jitter will decrease a little bit.
>>>
>>> This is the output I get for 64 Studio 3.0-beta3:
>>>
>>> spinymouse-sudo@64studio:~$ cat /proc/asound/timers
>>> G0: system timer : 1000.000us (10000000 ticks)
>>> P0-0-0: PCM playback 0-0-0 : SLAVE
>>> P0-0-1: PCM capture 0-0-1 : SLAVE
>>>   Client sequencer queue 0 : stopped
>>> _______________________________________________
>>> Linux-audio-dev mailing list
>>> Linux-audio-dev@...
>>> http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
>>>
>>>      
>>      
>> _______________________________________________
>> Linux-audio-dev mailing list
>> Linux-audio-dev@...
>> http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
>>
>>    
>
>
>      
>
>  

--
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[Ralf Mardorf]

Oops, I forgot something too:

spinymouse-sudo@64studio:~$ ll /dev/hpet
bash: ll: command not found
spinymouse-sudo@64studio:~$ ls /dev | grep hpet
hpet

Ralf Mardorf wrote:

> Thank you Emanuel for this thread :)
> thank you James for the information :)
>
> hopefully this might narrow down my trouble with MIDI jitter for
> external equipment, OTOH I don't have any MIDI jitter for MIDI internal
> Linux. ALSA MIDI and JACK MIDI seems to be fine what ever timer I use,
> this means there is absolutely no jitter when using a Linux sequencer to
> control a Linux synth. Jitter only occurs when using my USB MIDInterface
> to control external MIDI equipment. Unfortunately I can't get my
> Envy24's MPU working.
>
> There seems to be no hrtimer available yet:
>
> $ lsmod | grep snd_hrtimer
> $ lsmod | grep timer
> snd_timer              22024  2 snd_pcm,snd_seq
> snd                    63800  21
> snd_ice1712,snd_ak4xxx_adda,snd_cs8427,snd_ac97_codec,snd_i2c,snd_mpu401_uart,snd_usb_audio,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_hwdep,snd_seq_oss,snd_rawmidi,snd_seq,snd_timer,snd_seq_device
> $ uname -a
> Linux 64studio 2.6.29-1-multimedia-amd64 #1 SMP PREEMPT RT Thu Feb 26
> 16:18:05 UTC 2009 x86_64 GNU/Linux
>
> Before I start googleing. Is this a feature for 2.6.31 only? I'm still
> not able to boot the .31 kernel-rt from the Suse 11.2 RC repository and
> compiling for Suse also failed, but in the past I never had trouble to
> build kernel-rt for Debian/ Ubuntu based 64 Studio. Maybe I should try
> to build a kernel .31 for 64 Studio? Or is it just a module I need to
> add? Or is my hardware missing something?
>
> Going to use Google now.
>
> Bye,
> Ralf
>
> James Warden wrote:
>  
>> I forgot to add that snd_hrtimer is used by jackd.
>> If I turn jackd off, the snd_hrtimer module is not used:
>>
>> $ lsmod | grep timer
>> snd_hrtimer             2148  0 ## <<< not used
>> snd_timer              17408  3 snd_hrtimer,snd_seq,snd_pcm
>>
>> J.
>>
>> --- On Sat, 11/7/09, James Warden <warjamy@...> wrote:
>>
>>  
>>    
>>> From: James Warden <warjamy@...>
>>> Subject: Re: [LAD] timers
>>> To: "Emanuel Rumpf" <xbran@...>, "Ralf Mardorf" <ralf.mardorf@...>
>>> Cc: linux-audio-dev@...
>>> Date: Saturday, November 7, 2009, 7:34 AM
>>> Hi guys,
>>>
>>> Here is what I have:
>>>
>>>
>>> $ cat /proc/asound/timers
>>> G0: system timer : 1000.000us (10000000 ticks)
>>> G3: HR timer : 0.001us (1000000000 ticks)
>>>   Client sequencer queue 0 : running
>>> P1-0-0: PCM playback 1-0-0 : SLAVE
>>> P1-0-1: PCM capture 1-0-1 : SLAVE
>>>
>>> Ralf, you do not benefit from a high res timer. See how
>>> much more precise the HR timer is from the output above.
>>> Check which snd timer you have loaded:
>>>
>>> $ lsmod | grep timer
>>>
>>> snd_hrtimer        
>>>    2148  1
>>> snd_timer            
>>> 17408  3 snd_hrtimer,snd_seq,snd_pcm
>>>
>>> Of course, your h/w should have a HR timer:
>>>
>>> $ ll /dev/hpet
>>> crw-rw---- 1 root audio 10, 228 2009-11-05 12:59 /dev/hpet
>>>
>>> you can specify the clock source to jackd:
>>>
>>> $ jackd --help
>>> ...
>>> [ --clocksource OR -c [ c(ycle) | h(pet) | s(ystem) ]
>>> ...
>>>
>>>
>>>
>>> J.
>>>
>>>
>>> --- On Sat, 11/7/09, Ralf Mardorf <ralf.mardorf@...>
>>> wrote:
>>>
>>>    
>>>      
>>>> From: Ralf Mardorf <ralf.mardorf@...>
>>>> Subject: Re: [LAD] timers
>>>> To: "Emanuel Rumpf" <xbran@...>
>>>> Cc: linux-audio-dev@...
>>>> Date: Saturday, November 7, 2009, 7:04 AM
>>>> Emanuel Rumpf wrote:
>>>>      
>>>>        
>>>>> Hi
>>>>>
>>>>> I'm confused about all the timers.
>>>>>
>>>>> There is:
>>>>> - system timer
>>>>> - hpet (high precision event timer)
>>>>> - hr-timer (high resolution timer)
>>>>> - rtc (real time clock)
>>>>> - cyclic (what's that? a coded loop?)
>>>>> - anything else ?
>>>>>
>>>>>
>>>>> What is the relation of all these ?
>>>>> Which hardware devices are actually used by those
>>>>>        
>>>>>          
>>> ?
>>>    
>>>      
>>>>> Which is the prefered timer for sequencing ?
>>>>>        
>>>>>          
>>> hr-timer
>>>    
>>>      
>>>> / rtc ?
>>>>      
>>>>        
>>>>>    
>>>>>        
>>>>>          
>>>> If hardware is fine with Linux real-time audio, if I
>>>> understand
>>>> correctly, the preferred timer for MIDI sequencers is
>>>> (should be) system
>>>> timer at ! 1000 Hz ! For my hardware, that has got
>>>>      
>>>>        
>>> problems
>>>    
>>>      
>>>> with
>>>> real-time audio, it's PCM playback and PCM capture.
>>>>      
>>>>        
>>> Using
>>>    
>>>      
>>>> this timers
>>>> MIDI jitter will decrease a little bit.
>>>>
>>>> This is the output I get for 64 Studio 3.0-beta3:
>>>>
>>>> spinymouse-sudo@64studio:~$ cat /proc/asound/timers
>>>> G0: system timer : 1000.000us (10000000 ticks)
>>>> P0-0-0: PCM playback 0-0-0 : SLAVE
>>>> P0-0-1: PCM capture 0-0-1 : SLAVE
>>>>   Client sequencer queue 0 : stopped
>>>> _______________________________________________
>>>> Linux-audio-dev mailing list
>>>> Linux-audio-dev@...
>>>> http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
>>>>
>>>>      
>>>>        
>>>      
>>> _______________________________________________
>>> Linux-audio-dev mailing list
>>> Linux-audio-dev@...
>>> http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
>>>
>>>    
>>>      
>>      
>>
>>  
>>    
>
>  

--
Secret of Tux: http://images.wallaceandgromit.com/user_uploads/forum_thumbnails/5/75/355.jpg
"Gromit bit me" says HMV dog: http://img.dailymail.co.uk/i/pix/2007/03_03/GomitHMVPA_468x319.jpg

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[James Warden]

Ralf,

It depends how ALSA was compiled in the kernel. Here is my kernel config related to this matter:


CONFIG_SND=m
CONFIG_SND_TIMER=m
CONFIG_SND_PCM=m
CONFIG_SND_HWDEP=m
CONFIG_SND_RAWMIDI=m
CONFIG_SND_SEQUENCER=m
CONFIG_SND_SEQ_DUMMY=m
# CONFIG_SND_MIXER_OSS is not set
# CONFIG_SND_PCM_OSS is not set
# CONFIG_SND_SEQUENCER_OSS is not set
CONFIG_SND_HRTIMER=m
CONFIG_SND_SEQ_HRTIMER_DEFAULT=y

J.

--- On Sat, 11/7/09, Ralf Mardorf <ralf.mardorf@...> wrote:

> From: Ralf Mardorf <ralf.mardorf@...>
> Subject: Re: [LAD] timers
> To: "James Warden" <warjamy@...>
> Cc: "Emanuel Rumpf" <xbran@...>, linux-audio-dev@...
> Date: Saturday, November 7, 2009, 8:36 AM
> Thank you Emanuel for this thread :)
> thank you James for the information :)
>
> hopefully this might narrow down my trouble with MIDI
> jitter for external equipment, OTOH I don't have any MIDI
> jitter for MIDI internal Linux. ALSA MIDI and JACK MIDI
> seems to be fine what ever timer I use, this means there is
> absolutely no jitter when using a Linux sequencer to control
> a Linux synth. Jitter only occurs when using my USB
> MIDInterface to control external MIDI equipment.
> Unfortunately I can't get my Envy24's MPU working.
>
> There seems to be no hrtimer available yet:
>
> $ lsmod | grep snd_hrtimer
> $ lsmod | grep timer
> snd_timer             
> 22024  2 snd_pcm,snd_seq
> snd               
>     63800  21
> snd_ice1712,snd_ak4xxx_adda,snd_cs8427,snd_ac97_codec,snd_i2c,snd_mpu401_uart,snd_usb_audio,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_hwdep,snd_seq_oss,snd_rawmidi,snd_seq,snd_timer,snd_seq_device
> $ uname -a
> Linux 64studio 2.6.29-1-multimedia-amd64 #1 SMP PREEMPT RT
> Thu Feb 26 16:18:05 UTC 2009 x86_64 GNU/Linux
>
> Before I start googleing. Is this a feature for 2.6.31
> only? I'm still not able to boot the .31 kernel-rt from the
> Suse 11.2 RC repository and compiling for Suse also failed,
> but in the past I never had trouble to build kernel-rt for
> Debian/ Ubuntu based 64 Studio. Maybe I should try to build
> a kernel .31 for 64 Studio? Or is it just a module I need to
> add? Or is my hardware missing something?
>
> Going to use Google now.
>
> Bye,
> Ralf
>
> James Warden wrote:
> > I forgot to add that snd_hrtimer is used by jackd.
> > If I turn jackd off, the snd_hrtimer module is not
> used:
> >
> > $ lsmod | grep timer
> > snd_hrtimer         
>    2148  0 ## <<< not used
> > snd_timer           
>   17408  3 snd_hrtimer,snd_seq,snd_pcm
> >
> > J.
> >
> > --- On Sat, 11/7/09, James Warden <warjamy@...>
> wrote:
> >
> >   
> >> From: James Warden <warjamy@...>
> >> Subject: Re: [LAD] timers
> >> To: "Emanuel Rumpf" <xbran@...>,
> "Ralf Mardorf" <ralf.mardorf@...>
> >> Cc: linux-audio-dev@...
> >> Date: Saturday, November 7, 2009, 7:34 AM
> >> Hi guys,
> >>
> >> Here is what I have:
> >>
> >>
> >> $ cat /proc/asound/timers
> >> G0: system timer : 1000.000us (10000000 ticks)
> >> G3: HR timer : 0.001us (1000000000 ticks)
> >>   Client sequencer queue 0 :
> running
> >> P1-0-0: PCM playback 1-0-0 : SLAVE
> >> P1-0-1: PCM capture 1-0-1 : SLAVE
> >>
> >> Ralf, you do not benefit from a high res timer.
> See how
> >> much more precise the HR timer is from the output
> above.
> >> Check which snd timer you have loaded:
> >>
> >> $ lsmod | grep timer
> >>
> >> snd_hrtimer         
>   2148  1
> >> snd_timer         
>    17408  3 snd_hrtimer,snd_seq,snd_pcm
> >>
> >> Of course, your h/w should have a HR timer:
> >>
> >> $ ll /dev/hpet
> >> crw-rw---- 1 root audio 10, 228 2009-11-05 12:59
> /dev/hpet
> >>
> >> you can specify the clock source to jackd:
> >>
> >> $ jackd --help
> >> ...
> >> [ --clocksource OR -c [ c(ycle) | h(pet) |
> s(ystem) ]
> >> ...
> >>
> >>
> >>
> >> J.
> >>
> >>
> >> --- On Sat, 11/7/09, Ralf Mardorf <ralf.mardorf@...>
> >> wrote:
> >>
> >>     
> >>> From: Ralf Mardorf <ralf.mardorf@...>
> >>> Subject: Re: [LAD] timers
> >>> To: "Emanuel Rumpf" <xbran@...>
> >>> Cc: linux-audio-dev@...
> >>> Date: Saturday, November 7, 2009, 7:04 AM
> >>> Emanuel Rumpf wrote:
> >>>       
> >>>> Hi
> >>>>
> >>>> I'm confused about all the timers.
> >>>>
> >>>> There is:
> >>>> - system timer
> >>>> - hpet (high precision event timer)
> >>>> - hr-timer (high resolution timer)
> >>>> - rtc (real time clock)
> >>>> - cyclic (what's that? a coded loop?)
> >>>> - anything else ?
> >>>>
> >>>>
> >>>> What is the relation of all these ?
> >>>> Which hardware devices are actually used
> by those
> >>>>         
> >> ?
> >>     
> >>>> Which is the prefered timer for sequencing
> ?
> >>>>         
> >> hr-timer
> >>     
> >>> / rtc ?
> >>>       
> >>>>           
> >>> If hardware is fine with Linux real-time
> audio, if I
> >>> understand correctly, the preferred timer for
> MIDI sequencers is
> >>> (should be) system timer at ! 1000 Hz ! For my
> hardware, that has got
> >>>       
> >> problems
> >>     
> >>> with real-time audio, it's PCM playback and
> PCM capture.
> >>>       
> >> Using
> >>     
> >>> this timers MIDI jitter will decrease a little
> bit.
> >>>
> >>> This is the output I get for 64 Studio
> 3.0-beta3:
> >>>
> >>> spinymouse-sudo@64studio:~$ cat
> /proc/asound/timers
> >>> G0: system timer : 1000.000us (10000000
> ticks)
> >>> P0-0-0: PCM playback 0-0-0 : SLAVE
> >>> P0-0-1: PCM capture 0-0-1 : SLAVE
> >>>   Client sequencer queue 0 :
> stopped
> >>>
> _______________________________________________
> >>> Linux-audio-dev mailing list
> >>> Linux-audio-dev@...
> >>> http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
> >>>
> >>>       
> >>   
>    _______________________________________________
> >> Linux-audio-dev mailing list
> >> Linux-audio-dev@...
> >> http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
> >>
> >>     
> >
> >
> >       
> >   
>
> -- Secret of Tux: http://images.wallaceandgromit.com/user_uploads/forum_thumbnails/5/75/355.jpg
> "Gromit bit me" says HMV dog: http://img.dailymail.co.uk/i/pix/2007/03_03/GomitHMVPA_468x319.jpg
>
>

     
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[Ralf Mardorf]

James Warden wrote:

> Ralf,
>
> It depends how ALSA was compiled in the kernel. Here is my kernel config related to this matter:
>
>
> CONFIG_SND=m
> CONFIG_SND_TIMER=m
> CONFIG_SND_PCM=m
> CONFIG_SND_HWDEP=m
> CONFIG_SND_RAWMIDI=m
> CONFIG_SND_SEQUENCER=m
> CONFIG_SND_SEQ_DUMMY=m
> # CONFIG_SND_MIXER_OSS is not set
> # CONFIG_SND_PCM_OSS is not set
> # CONFIG_SND_SEQUENCER_OSS is not set
> CONFIG_SND_HRTIMER=m
> CONFIG_SND_SEQ_HRTIMER_DEFAULT=y
>
> J.

There is another question I've got :S.

spinymouse-sudo@64studio:~$ ls -l /dev | grep hpet
crw-rw----  1 root   root     10, 228 2009-11-07 13:38 hpet

The group for hpet isn't audio, thus I guess a user won't be able to use
it?!

Oops, "# CONFIG_SND_HRTIMER is not set", has this now become something I
should post to the 64 Studio list? It's the default for the 64 Studio
kernel. It's not a self build kernel.

spinymouse-sudo@64studio:~$ cat /boot/config-2.6.29-1-multimedia-amd64 |
grep CONFIG_SND
CONFIG_SND=m
CONFIG_SND_TIMER=m
CONFIG_SND_PCM=m
CONFIG_SND_HWDEP=m
CONFIG_SND_RAWMIDI=m
CONFIG_SND_JACK=y
CONFIG_SND_SEQUENCER=m
CONFIG_SND_SEQ_DUMMY=m
CONFIG_SND_OSSEMUL=y
CONFIG_SND_MIXER_OSS=m
CONFIG_SND_PCM_OSS=m
CONFIG_SND_PCM_OSS_PLUGINS=y
CONFIG_SND_SEQUENCER_OSS=y
# CONFIG_SND_HRTIMER is not set
# CONFIG_SND_DYNAMIC_MINORS is not set
CONFIG_SND_SUPPORT_OLD_API=y
CONFIG_SND_VERBOSE_PROCFS=y
# CONFIG_SND_VERBOSE_PRINTK is not set
# CONFIG_SND_DEBUG is not set
CONFIG_SND_VMASTER=y
CONFIG_SND_MPU401_UART=m
CONFIG_SND_OPL3_LIB=m
CONFIG_SND_VX_LIB=m
CONFIG_SND_AC97_CODEC=m
CONFIG_SND_DRIVERS=y
CONFIG_SND_PCSP=m
CONFIG_SND_DUMMY=m
CONFIG_SND_VIRMIDI=m
CONFIG_SND_MTS64=m
CONFIG_SND_SERIAL_U16550=m
CONFIG_SND_MPU401=m
CONFIG_SND_PORTMAN2X4=m
CONFIG_SND_AC97_POWER_SAVE=y
CONFIG_SND_AC97_POWER_SAVE_DEFAULT=0
CONFIG_SND_SB_COMMON=m
CONFIG_SND_SB16_DSP=m
CONFIG_SND_PCI=y
CONFIG_SND_AD1889=m
CONFIG_SND_ALS300=m
CONFIG_SND_ALS4000=m
CONFIG_SND_ALI5451=m
CONFIG_SND_ATIIXP=m
CONFIG_SND_ATIIXP_MODEM=m
CONFIG_SND_AU8810=m
CONFIG_SND_AU8820=m
CONFIG_SND_AU8830=m
# CONFIG_SND_AW2 is not set
CONFIG_SND_AZT3328=m
CONFIG_SND_BT87X=m
# CONFIG_SND_BT87X_OVERCLOCK is not set
CONFIG_SND_CA0106=m
CONFIG_SND_CMIPCI=m
CONFIG_SND_OXYGEN_LIB=m
CONFIG_SND_OXYGEN=m
CONFIG_SND_CS4281=m
CONFIG_SND_CS46XX=m
CONFIG_SND_CS46XX_NEW_DSP=y
CONFIG_SND_CS5530=m
CONFIG_SND_DARLA20=m
CONFIG_SND_GINA20=m
CONFIG_SND_LAYLA20=m
CONFIG_SND_DARLA24=m
CONFIG_SND_GINA24=m
CONFIG_SND_LAYLA24=m
CONFIG_SND_MONA=m
CONFIG_SND_MIA=m
CONFIG_SND_ECHO3G=m
CONFIG_SND_INDIGO=m
CONFIG_SND_INDIGOIO=m
CONFIG_SND_INDIGODJ=m
CONFIG_SND_EMU10K1=m
CONFIG_SND_EMU10K1X=m
CONFIG_SND_ENS1370=m
CONFIG_SND_ENS1371=m
CONFIG_SND_ES1938=m
CONFIG_SND_ES1968=m
CONFIG_SND_FM801=m
CONFIG_SND_FM801_TEA575X_BOOL=y
CONFIG_SND_FM801_TEA575X=m
CONFIG_SND_HDA_INTEL=m
# CONFIG_SND_HDA_HWDEP is not set
CONFIG_SND_HDA_INPUT_BEEP=y
CONFIG_SND_HDA_CODEC_REALTEK=y
CONFIG_SND_HDA_CODEC_ANALOG=y
CONFIG_SND_HDA_CODEC_SIGMATEL=y
CONFIG_SND_HDA_CODEC_VIA=y
CONFIG_SND_HDA_CODEC_ATIHDMI=y
CONFIG_SND_HDA_CODEC_NVHDMI=y
CONFIG_SND_HDA_CODEC_INTELHDMI=y
CONFIG_SND_HDA_ELD=y
CONFIG_SND_HDA_CODEC_CONEXANT=y
CONFIG_SND_HDA_CODEC_CMEDIA=y
CONFIG_SND_HDA_CODEC_SI3054=y
CONFIG_SND_HDA_GENERIC=y
CONFIG_SND_HDA_POWER_SAVE=y
CONFIG_SND_HDA_POWER_SAVE_DEFAULT=0
CONFIG_SND_HDSP=m
CONFIG_SND_HDSPM=m
CONFIG_SND_HIFIER=m
CONFIG_SND_ICE1712=m
CONFIG_SND_ICE1724=m
CONFIG_SND_INTEL8X0=m
CONFIG_SND_INTEL8X0M=m
CONFIG_SND_KORG1212=m
CONFIG_SND_MAESTRO3=m
CONFIG_SND_MIXART=m
CONFIG_SND_NM256=m
CONFIG_SND_PCXHR=m
CONFIG_SND_RIPTIDE=m
CONFIG_SND_RME32=m
CONFIG_SND_RME96=m
CONFIG_SND_RME9652=m
CONFIG_SND_SONICVIBES=m
CONFIG_SND_TRIDENT=m
CONFIG_SND_VIA82XX=m
CONFIG_SND_VIA82XX_MODEM=m
CONFIG_SND_VIRTUOSO=m
CONFIG_SND_VX222=m
CONFIG_SND_YMFPCI=m
CONFIG_SND_SPI=y
CONFIG_SND_USB=y
CONFIG_SND_USB_AUDIO=m
CONFIG_SND_USB_USX2Y=m
CONFIG_SND_USB_CAIAQ=m
CONFIG_SND_USB_CAIAQ_INPUT=y
CONFIG_SND_USB_US122L=m
CONFIG_SND_PCMCIA=y
CONFIG_SND_VXPOCKET=m
CONFIG_SND_PDAUDIOCF=m
# CONFIG_SND_SOC is not set
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[Ray Rashif]

> CONFIG_SND=m
> CONFIG_SND_TIMER=m
> CONFIG_SND_PCM=m
> CONFIG_SND_HWDEP=m
> CONFIG_SND_RAWMIDI=m
> CONFIG_SND_SEQUENCER=m
> CONFIG_SND_SEQ_DUMMY=m
> # CONFIG_SND_MIXER_OSS is not set
> # CONFIG_SND_PCM_OSS is not set
> # CONFIG_SND_SEQUENCER_OSS is not set
> CONFIG_SND_HRTIMER=m
> CONFIG_SND_SEQ_HRTIMER_DEFAULT=y

Are defaults. You need:

CONFIG_HPET_TIMER=y

CONFIG_HPET_EMULATE_RTC=y

CONFIG_HPET=y

CONFIG_HPET_MMAP=y

It's inside one of the first few menus.

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[James Warden]

yeah, I have added a few things in a startup script. Among other things, I have:

chgrp audio /dev/hpet
echo 1024 > /proc/sys/dev/hpet/max-user-freq
modprobe snd-hrtimer

The modprobe may not be needed anymore as my kernel is using hr-timer by default. I wrote this script quite some time ago and forgot about it :)

J.

--- On Sat, 11/7/09, Ralf Mardorf <ralf.mardorf@...> wrote:

> From: Ralf Mardorf <ralf.mardorf@...>
> Subject: Re: [LAD] timers
> To:
> Cc: linux-audio-dev@...
> Date: Saturday, November 7, 2009, 8:52 AM
> James Warden wrote:
> > Ralf,
> >
> > It depends how ALSA was compiled in the kernel. Here
> is my kernel config related to this matter:
> >
> >
> > CONFIG_SND=m
> > CONFIG_SND_TIMER=m
> > CONFIG_SND_PCM=m
> > CONFIG_SND_HWDEP=m
> > CONFIG_SND_RAWMIDI=m
> > CONFIG_SND_SEQUENCER=m
> > CONFIG_SND_SEQ_DUMMY=m
> > # CONFIG_SND_MIXER_OSS is not set
> > # CONFIG_SND_PCM_OSS is not set
> > # CONFIG_SND_SEQUENCER_OSS is not set
> > CONFIG_SND_HRTIMER=m
> > CONFIG_SND_SEQ_HRTIMER_DEFAULT=y
> >
> > J.
>
> There is another question I've got :S.
>
> spinymouse-sudo@64studio:~$ ls -l /dev | grep hpet
> crw-rw----  1 root   root 
>    10, 228 2009-11-07 13:38 hpet
>
> The group for hpet isn't audio, thus I guess a user won't
> be able to use
> it?!
>
> Oops, "# CONFIG_SND_HRTIMER is not set", has this now
> become something I
> should post to the 64 Studio list? It's the default for the
> 64 Studio
> kernel. It's not a self build kernel.
>
> spinymouse-sudo@64studio:~$ cat
> /boot/config-2.6.29-1-multimedia-amd64 |
> grep CONFIG_SND
> CONFIG_SND=m
> CONFIG_SND_TIMER=m
> CONFIG_SND_PCM=m
> CONFIG_SND_HWDEP=m
> CONFIG_SND_RAWMIDI=m
> CONFIG_SND_JACK=y
> CONFIG_SND_SEQUENCER=m
> CONFIG_SND_SEQ_DUMMY=m
> CONFIG_SND_OSSEMUL=y
> CONFIG_SND_MIXER_OSS=m
> CONFIG_SND_PCM_OSS=m
> CONFIG_SND_PCM_OSS_PLUGINS=y
> CONFIG_SND_SEQUENCER_OSS=y
> # CONFIG_SND_HRTIMER is not set
> # CONFIG_SND_DYNAMIC_MINORS is not set
> CONFIG_SND_SUPPORT_OLD_API=y
> CONFIG_SND_VERBOSE_PROCFS=y
> # CONFIG_SND_VERBOSE_PRINTK is not set
> # CONFIG_SND_DEBUG is not set
> CONFIG_SND_VMASTER=y
> CONFIG_SND_MPU401_UART=m
> CONFIG_SND_OPL3_LIB=m
> CONFIG_SND_VX_LIB=m
> CONFIG_SND_AC97_CODEC=m
> CONFIG_SND_DRIVERS=y
> CONFIG_SND_PCSP=m
> CONFIG_SND_DUMMY=m
> CONFIG_SND_VIRMIDI=m
> CONFIG_SND_MTS64=m
> CONFIG_SND_SERIAL_U16550=m
> CONFIG_SND_MPU401=m
> CONFIG_SND_PORTMAN2X4=m
> CONFIG_SND_AC97_POWER_SAVE=y
> CONFIG_SND_AC97_POWER_SAVE_DEFAULT=0
> CONFIG_SND_SB_COMMON=m
> CONFIG_SND_SB16_DSP=m
> CONFIG_SND_PCI=y
> CONFIG_SND_AD1889=m
> CONFIG_SND_ALS300=m
> CONFIG_SND_ALS4000=m
> CONFIG_SND_ALI5451=m
> CONFIG_SND_ATIIXP=m
> CONFIG_SND_ATIIXP_MODEM=m
> CONFIG_SND_AU8810=m
> CONFIG_SND_AU8820=m
> CONFIG_SND_AU8830=m
> # CONFIG_SND_AW2 is not set
> CONFIG_SND_AZT3328=m
> CONFIG_SND_BT87X=m
> # CONFIG_SND_BT87X_OVERCLOCK is not set
> CONFIG_SND_CA0106=m
> CONFIG_SND_CMIPCI=m
> CONFIG_SND_OXYGEN_LIB=m
> CONFIG_SND_OXYGEN=m
> CONFIG_SND_CS4281=m
> CONFIG_SND_CS46XX=m
> CONFIG_SND_CS46XX_NEW_DSP=y
> CONFIG_SND_CS5530=m
> CONFIG_SND_DARLA20=m
> CONFIG_SND_GINA20=m
> CONFIG_SND_LAYLA20=m
> CONFIG_SND_DARLA24=m
> CONFIG_SND_GINA24=m
> CONFIG_SND_LAYLA24=m
> CONFIG_SND_MONA=m
> CONFIG_SND_MIA=m
> CONFIG_SND_ECHO3G=m
> CONFIG_SND_INDIGO=m
> CONFIG_SND_INDIGOIO=m
> CONFIG_SND_INDIGODJ=m
> CONFIG_SND_EMU10K1=m
> CONFIG_SND_EMU10K1X=m
> CONFIG_SND_ENS1370=m
> CONFIG_SND_ENS1371=m
> CONFIG_SND_ES1938=m
> CONFIG_SND_ES1968=m
> CONFIG_SND_FM801=m
> CONFIG_SND_FM801_TEA575X_BOOL=y
> CONFIG_SND_FM801_TEA575X=m
> CONFIG_SND_HDA_INTEL=m
> # CONFIG_SND_HDA_HWDEP is not set
> CONFIG_SND_HDA_INPUT_BEEP=y
> CONFIG_SND_HDA_CODEC_REALTEK=y
> CONFIG_SND_HDA_CODEC_ANALOG=y
> CONFIG_SND_HDA_CODEC_SIGMATEL=y
> CONFIG_SND_HDA_CODEC_VIA=y
> CONFIG_SND_HDA_CODEC_ATIHDMI=y
> CONFIG_SND_HDA_CODEC_NVHDMI=y
> CONFIG_SND_HDA_CODEC_INTELHDMI=y
> CONFIG_SND_HDA_ELD=y
> CONFIG_SND_HDA_CODEC_CONEXANT=y
> CONFIG_SND_HDA_CODEC_CMEDIA=y
> CONFIG_SND_HDA_CODEC_SI3054=y
> CONFIG_SND_HDA_GENERIC=y
> CONFIG_SND_HDA_POWER_SAVE=y
> CONFIG_SND_HDA_POWER_SAVE_DEFAULT=0
> CONFIG_SND_HDSP=m
> CONFIG_SND_HDSPM=m
> CONFIG_SND_HIFIER=m
> CONFIG_SND_ICE1712=m
> CONFIG_SND_ICE1724=m
> CONFIG_SND_INTEL8X0=m
> CONFIG_SND_INTEL8X0M=m
> CONFIG_SND_KORG1212=m
> CONFIG_SND_MAESTRO3=m
> CONFIG_SND_MIXART=m
> CONFIG_SND_NM256=m
> CONFIG_SND_PCXHR=m
> CONFIG_SND_RIPTIDE=m
> CONFIG_SND_RME32=m
> CONFIG_SND_RME96=m
> CONFIG_SND_RME9652=m
> CONFIG_SND_SONICVIBES=m
> CONFIG_SND_TRIDENT=m
> CONFIG_SND_VIA82XX=m
> CONFIG_SND_VIA82XX_MODEM=m
> CONFIG_SND_VIRTUOSO=m
> CONFIG_SND_VX222=m
> CONFIG_SND_YMFPCI=m
> CONFIG_SND_SPI=y
> CONFIG_SND_USB=y
> CONFIG_SND_USB_AUDIO=m
> CONFIG_SND_USB_USX2Y=m
> CONFIG_SND_USB_CAIAQ=m
> CONFIG_SND_USB_CAIAQ_INPUT=y
> CONFIG_SND_USB_US122L=m
> CONFIG_SND_PCMCIA=y
> CONFIG_SND_VXPOCKET=m
> CONFIG_SND_PDAUDIOCF=m
> # CONFIG_SND_SOC is not set
> _______________________________________________
> Linux-audio-dev mailing list
> Linux-audio-dev@...
> http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
>

     
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[James Warden]

yeps, forgot to copy this part of the config here, thanks :)

J.

--- On Sat, 11/7/09, Ray Rashif <schivmeister@...> wrote:

> From: Ray Rashif <schivmeister@...>
> Subject: Re: [LAD] timers
> To: "Linux Audio Developers" <linux-audio-dev@...>
> Date: Saturday, November 7, 2009, 8:53 AM
> >
> CONFIG_SND=m
> > CONFIG_SND_TIMER=m
> > CONFIG_SND_PCM=m
> > CONFIG_SND_HWDEP=m
> > CONFIG_SND_RAWMIDI=m
>
>
> > CONFIG_SND_SEQUENCER=m
> > CONFIG_SND_SEQ_DUMMY=m
> > # CONFIG_SND_MIXER_OSS is not set
> > # CONFIG_SND_PCM_OSS is not set
> > # CONFIG_SND_SEQUENCER_OSS is not set
> > CONFIG_SND_HRTIMER=m
> > CONFIG_SND_SEQ_HRTIMER_DEFAULT=y
>
>
> Are defaults. You need:
> CONFIG_HPET_TIMER=yCONFIG_HPET_EMULATE_RTC=yCONFIG_HPET=yCONFIG_HPET_MMAP=y
> It's inside one of the first few
> menus.
>
>
>
> -----Inline Attachment Follows-----
>
> _______________________________________________
> Linux-audio-dev mailing list
> Linux-audio-dev@...
> http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
>

     
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[Ralf Mardorf]

Thank you very much James and Ray :).

Ralf

James Warden wrote:

> yeah, I have added a few things in a startup script. Among other things, I have:
>
> chgrp audio /dev/hpet
> echo 1024 > /proc/sys/dev/hpet/max-user-freq
> modprobe snd-hrtimer
>
> The modprobe may not be needed anymore as my kernel is using hr-timer by default. I wrote this script quite some time ago and forgot about it :)
>
> J.
>
> --- On Sat, 11/7/09, Ralf Mardorf <ralf.mardorf@...> wrote:
>
>  
>> From: Ralf Mardorf <ralf.mardorf@...>
>> Subject: Re: [LAD] timers
>> To:
>> Cc: linux-audio-dev@...
>> Date: Saturday, November 7, 2009, 8:52 AM
>> James Warden wrote:
>>    
>>> Ralf,
>>>
>>> It depends how ALSA was compiled in the kernel. Here
>>>      
>> is my kernel config related to this matter:
>>    
>>> CONFIG_SND=m
>>> CONFIG_SND_TIMER=m
>>> CONFIG_SND_PCM=m
>>> CONFIG_SND_HWDEP=m
>>> CONFIG_SND_RAWMIDI=m
>>> CONFIG_SND_SEQUENCER=m
>>> CONFIG_SND_SEQ_DUMMY=m
>>> # CONFIG_SND_MIXER_OSS is not set
>>> # CONFIG_SND_PCM_OSS is not set
>>> # CONFIG_SND_SEQUENCER_OSS is not set
>>> CONFIG_SND_HRTIMER=m
>>> CONFIG_SND_SEQ_HRTIMER_DEFAULT=y
>>>
>>> J.
>>>      
>> There is another question I've got :S.
>>
>> spinymouse-sudo@64studio:~$ ls -l /dev | grep hpet
>> crw-rw----  1 root   root
>>    10, 228 2009-11-07 13:38 hpet
>>
>> The group for hpet isn't audio, thus I guess a user won't
>> be able to use
>> it?!
>>
>> Oops, "# CONFIG_SND_HRTIMER is not set", has this now
>> become something I
>> should post to the 64 Studio list? It's the default for the
>> 64 Studio
>> kernel. It's not a self build kernel.
>>
>> spinymouse-sudo@64studio:~$ cat
>> /boot/config-2.6.29-1-multimedia-amd64 |
>> grep CONFIG_SND
>> CONFIG_SND=m
>> CONFIG_SND_TIMER=m
>> CONFIG_SND_PCM=m
>> CONFIG_SND_HWDEP=m
>> CONFIG_SND_RAWMIDI=m
>> CONFIG_SND_JACK=y
>> CONFIG_SND_SEQUENCER=m
>> CONFIG_SND_SEQ_DUMMY=m
>> CONFIG_SND_OSSEMUL=y
>> CONFIG_SND_MIXER_OSS=m
>> CONFIG_SND_PCM_OSS=m
>> CONFIG_SND_PCM_OSS_PLUGINS=y
>> CONFIG_SND_SEQUENCER_OSS=y
>> # CONFIG_SND_HRTIMER is not set
>> # CONFIG_SND_DYNAMIC_MINORS is not set
>> CONFIG_SND_SUPPORT_OLD_API=y
>> CONFIG_SND_VERBOSE_PROCFS=y
>> # CONFIG_SND_VERBOSE_PRINTK is not set
>> # CONFIG_SND_DEBUG is not set
>> CONFIG_SND_VMASTER=y
>> CONFIG_SND_MPU401_UART=m
>> CONFIG_SND_OPL3_LIB=m
>> CONFIG_SND_VX_LIB=m
>> CONFIG_SND_AC97_CODEC=m
>> CONFIG_SND_DRIVERS=y
>> CONFIG_SND_PCSP=m
>> CONFIG_SND_DUMMY=m
>> CONFIG_SND_VIRMIDI=m
>> CONFIG_SND_MTS64=m
>> CONFIG_SND_SERIAL_U16550=m
>> CONFIG_SND_MPU401=m
>> CONFIG_SND_PORTMAN2X4=m
>> CONFIG_SND_AC97_POWER_SAVE=y
>> CONFIG_SND_AC97_POWER_SAVE_DEFAULT=0
>> CONFIG_SND_SB_COMMON=m
>> CONFIG_SND_SB16_DSP=m
>> CONFIG_SND_PCI=y
>> CONFIG_SND_AD1889=m
>> CONFIG_SND_ALS300=m
>> CONFIG_SND_ALS4000=m
>> CONFIG_SND_ALI5451=m
>> CONFIG_SND_ATIIXP=m
>> CONFIG_SND_ATIIXP_MODEM=m
>> CONFIG_SND_AU8810=m
>> CONFIG_SND_AU8820=m
>> CONFIG_SND_AU8830=m
>> # CONFIG_SND_AW2 is not set
>> CONFIG_SND_AZT3328=m
>> CONFIG_SND_BT87X=m
>> # CONFIG_SND_BT87X_OVERCLOCK is not set
>> CONFIG_SND_CA0106=m
>> CONFIG_SND_CMIPCI=m
>> CONFIG_SND_OXYGEN_LIB=m
>> CONFIG_SND_OXYGEN=m
>> CONFIG_SND_CS4281=m
>> CONFIG_SND_CS46XX=m
>> CONFIG_SND_CS46XX_NEW_DSP=y
>> CONFIG_SND_CS5530=m
>> CONFIG_SND_DARLA20=m
>> CONFIG_SND_GINA20=m
>> CONFIG_SND_LAYLA20=m
>> CONFIG_SND_DARLA24=m
>> CONFIG_SND_GINA24=m
>> CONFIG_SND_LAYLA24=m
>> CONFIG_SND_MONA=m
>> CONFIG_SND_MIA=m
>> CONFIG_SND_ECHO3G=m
>> CONFIG_SND_INDIGO=m
>> CONFIG_SND_INDIGOIO=m
>> CONFIG_SND_INDIGODJ=m
>> CONFIG_SND_EMU10K1=m
>> CONFIG_SND_EMU10K1X=m
>> CONFIG_SND_ENS1370=m
>> CONFIG_SND_ENS1371=m
>> CONFIG_SND_ES1938=m
>> CONFIG_SND_ES1968=m
>> CONFIG_SND_FM801=m
>> CONFIG_SND_FM801_TEA575X_BOOL=y
>> CONFIG_SND_FM801_TEA575X=m
>> CONFIG_SND_HDA_INTEL=m
>> # CONFIG_SND_HDA_HWDEP is not set
>> CONFIG_SND_HDA_INPUT_BEEP=y
>> CONFIG_SND_HDA_CODEC_REALTEK=y
>> CONFIG_SND_HDA_CODEC_ANALOG=y
>> CONFIG_SND_HDA_CODEC_SIGMATEL=y
>> CONFIG_SND_HDA_CODEC_VIA=y
>> CONFIG_SND_HDA_CODEC_ATIHDMI=y
>> CONFIG_SND_HDA_CODEC_NVHDMI=y
>> CONFIG_SND_HDA_CODEC_INTELHDMI=y
>> CONFIG_SND_HDA_ELD=y
>> CONFIG_SND_HDA_CODEC_CONEXANT=y
>> CONFIG_SND_HDA_CODEC_CMEDIA=y
>> CONFIG_SND_HDA_CODEC_SI3054=y
>> CONFIG_SND_HDA_GENERIC=y
>> CONFIG_SND_HDA_POWER_SAVE=y
>> CONFIG_SND_HDA_POWER_SAVE_DEFAULT=0
>> CONFIG_SND_HDSP=m
>> CONFIG_SND_HDSPM=m
>> CONFIG_SND_HIFIER=m
>> CONFIG_SND_ICE1712=m
>> CONFIG_SND_ICE1724=m
>> CONFIG_SND_INTEL8X0=m
>> CONFIG_SND_INTEL8X0M=m
>> CONFIG_SND_KORG1212=m
>> CONFIG_SND_MAESTRO3=m
>> CONFIG_SND_MIXART=m
>> CONFIG_SND_NM256=m
>> CONFIG_SND_PCXHR=m
>> CONFIG_SND_RIPTIDE=m
>> CONFIG_SND_RME32=m
>> CONFIG_SND_RME96=m
>> CONFIG_SND_RME9652=m
>> CONFIG_SND_SONICVIBES=m
>> CONFIG_SND_TRIDENT=m
>> CONFIG_SND_VIA82XX=m
>> CONFIG_SND_VIA82XX_MODEM=m
>> CONFIG_SND_VIRTUOSO=m
>> CONFIG_SND_VX222=m
>> CONFIG_SND_YMFPCI=m
>> CONFIG_SND_SPI=y
>> CONFIG_SND_USB=y
>> CONFIG_SND_USB_AUDIO=m
>> CONFIG_SND_USB_USX2Y=m
>> CONFIG_SND_USB_CAIAQ=m
>> CONFIG_SND_USB_CAIAQ_INPUT=y
>> CONFIG_SND_USB_US122L=m
>> CONFIG_SND_PCMCIA=y
>> CONFIG_SND_VXPOCKET=m
>> CONFIG_SND_PDAUDIOCF=m
>> # CONFIG_SND_SOC is not set
>> _______________________________________________
>> Linux-audio-dev mailing list
>> Linux-audio-dev@...
>> http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
>>
>>    
>
>
>      
>
>  

--
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[James Warden]

Another thing you can check:

dmesg | grep -i hpet

You'll see if your h/w supports it.

You can read more at
http://en.wikipedia.org/wiki/High_Precision_Event_Timer

J.

--- On Sat, 11/7/09, Ralf Mardorf <ralf.mardorf@...> wrote:

> From: Ralf Mardorf <ralf.mardorf@...>
> Subject: Re: [LAD] timers
> To: "James Warden" <warjamy@...>
> Cc: linux-audio-dev@...
> Date: Saturday, November 7, 2009, 8:57 AM
> Thank you very much James and Ray
> :).
>
> Ralf
>
> James Warden wrote:
> > yeah, I have added a few things in a startup script.
> Among other things, I have:
> >
> > chgrp audio /dev/hpet
> > echo 1024 > /proc/sys/dev/hpet/max-user-freq
> > modprobe snd-hrtimer
> >
> > The modprobe may not be needed anymore as my kernel is
> using hr-timer by default. I wrote this script quite some
> time ago and forgot about it :)
> >
> > J.
> >
> > --- On Sat, 11/7/09, Ralf Mardorf <ralf.mardorf@...>
> wrote:
> >
> >   
> >> From: Ralf Mardorf <ralf.mardorf@...>
> >> Subject: Re: [LAD] timers
> >> To: Cc: linux-audio-dev@...
> >> Date: Saturday, November 7, 2009, 8:52 AM
> >> James Warden wrote:
> >>     
> >>> Ralf,
> >>>
> >>> It depends how ALSA was compiled in the
> kernel. Here
> >>>       
> >> is my kernel config related to this matter:
> >>     
> >>> CONFIG_SND=m
> >>> CONFIG_SND_TIMER=m
> >>> CONFIG_SND_PCM=m
> >>> CONFIG_SND_HWDEP=m
> >>> CONFIG_SND_RAWMIDI=m
> >>> CONFIG_SND_SEQUENCER=m
> >>> CONFIG_SND_SEQ_DUMMY=m
> >>> # CONFIG_SND_MIXER_OSS is not set
> >>> # CONFIG_SND_PCM_OSS is not set
> >>> # CONFIG_SND_SEQUENCER_OSS is not set
> >>> CONFIG_SND_HRTIMER=m
> >>> CONFIG_SND_SEQ_HRTIMER_DEFAULT=y
> >>>
> >>> J.
> >>>       
> >> There is another question I've got :S.
> >>
> >> spinymouse-sudo@64studio:~$ ls -l /dev | grep
> hpet
> >> crw-rw----  1
> root   root    10, 228 2009-11-07
> 13:38 hpet
> >>
> >> The group for hpet isn't audio, thus I guess a
> user won't
> >> be able to use it?!
> >>
> >> Oops, "# CONFIG_SND_HRTIMER is not set", has this
> now
> >> become something I should post to the 64 Studio
> list? It's the default for the
> >> 64 Studio kernel. It's not a self build kernel.
> >>
> >> spinymouse-sudo@64studio:~$ cat
> >> /boot/config-2.6.29-1-multimedia-amd64 | grep
> CONFIG_SND
> >> CONFIG_SND=m
> >> CONFIG_SND_TIMER=m
> >> CONFIG_SND_PCM=m
> >> CONFIG_SND_HWDEP=m
> >> CONFIG_SND_RAWMIDI=m
> >> CONFIG_SND_JACK=y
> >> CONFIG_SND_SEQUENCER=m
> >> CONFIG_SND_SEQ_DUMMY=m
> >> CONFIG_SND_OSSEMUL=y
> >> CONFIG_SND_MIXER_OSS=m
> >> CONFIG_SND_PCM_OSS=m
> >> CONFIG_SND_PCM_OSS_PLUGINS=y
> >> CONFIG_SND_SEQUENCER_OSS=y
> >> # CONFIG_SND_HRTIMER is not set
> >> # CONFIG_SND_DYNAMIC_MINORS is not set
> >> CONFIG_SND_SUPPORT_OLD_API=y
> >> CONFIG_SND_VERBOSE_PROCFS=y
> >> # CONFIG_SND_VERBOSE_PRINTK is not set
> >> # CONFIG_SND_DEBUG is not set
> >> CONFIG_SND_VMASTER=y
> >> CONFIG_SND_MPU401_UART=m
> >> CONFIG_SND_OPL3_LIB=m
> >> CONFIG_SND_VX_LIB=m
> >> CONFIG_SND_AC97_CODEC=m
> >> CONFIG_SND_DRIVERS=y
> >> CONFIG_SND_PCSP=m
> >> CONFIG_SND_DUMMY=m
> >> CONFIG_SND_VIRMIDI=m
> >> CONFIG_SND_MTS64=m
> >> CONFIG_SND_SERIAL_U16550=m
> >> CONFIG_SND_MPU401=m
> >> CONFIG_SND_PORTMAN2X4=m
> >> CONFIG_SND_AC97_POWER_SAVE=y
> >> CONFIG_SND_AC97_POWER_SAVE_DEFAULT=0
> >> CONFIG_SND_SB_COMMON=m
> >> CONFIG_SND_SB16_DSP=m
> >> CONFIG_SND_PCI=y
> >> CONFIG_SND_AD1889=m
> >> CONFIG_SND_ALS300=m
> >> CONFIG_SND_ALS4000=m
> >> CONFIG_SND_ALI5451=m
> >> CONFIG_SND_ATIIXP=m
> >> CONFIG_SND_ATIIXP_MODEM=m
> >> CONFIG_SND_AU8810=m
> >> CONFIG_SND_AU8820=m
> >> CONFIG_SND_AU8830=m
> >> # CONFIG_SND_AW2 is not set
> >> CONFIG_SND_AZT3328=m
> >> CONFIG_SND_BT87X=m
> >> # CONFIG_SND_BT87X_OVERCLOCK is not set
> >> CONFIG_SND_CA0106=m
> >> CONFIG_SND_CMIPCI=m
> >> CONFIG_SND_OXYGEN_LIB=m
> >> CONFIG_SND_OXYGEN=m
> >> CONFIG_SND_CS4281=m
> >> CONFIG_SND_CS46XX=m
> >> CONFIG_SND_CS46XX_NEW_DSP=y
> >> CONFIG_SND_CS5530=m
> >> CONFIG_SND_DARLA20=m
> >> CONFIG_SND_GINA20=m
> >> CONFIG_SND_LAYLA20=m
> >> CONFIG_SND_DARLA24=m
> >> CONFIG_SND_GINA24=m
> >> CONFIG_SND_LAYLA24=m
> >> CONFIG_SND_MONA=m
> >> CONFIG_SND_MIA=m
> >> CONFIG_SND_ECHO3G=m
> >> CONFIG_SND_INDIGO=m
> >> CONFIG_SND_INDIGOIO=m
> >> CONFIG_SND_INDIGODJ=m
> >> CONFIG_SND_EMU10K1=m
> >> CONFIG_SND_EMU10K1X=m
> >> CONFIG_SND_ENS1370=m
> >> CONFIG_SND_ENS1371=m
> >> CONFIG_SND_ES1938=m
> >> CONFIG_SND_ES1968=m
> >> CONFIG_SND_FM801=m
> >> CONFIG_SND_FM801_TEA575X_BOOL=y
> >> CONFIG_SND_FM801_TEA575X=m
> >> CONFIG_SND_HDA_INTEL=m
> >> # CONFIG_SND_HDA_HWDEP is not set
> >> CONFIG_SND_HDA_INPUT_BEEP=y
> >> CONFIG_SND_HDA_CODEC_REALTEK=y
> >> CONFIG_SND_HDA_CODEC_ANALOG=y
> >> CONFIG_SND_HDA_CODEC_SIGMATEL=y
> >> CONFIG_SND_HDA_CODEC_VIA=y
> >> CONFIG_SND_HDA_CODEC_ATIHDMI=y
> >> CONFIG_SND_HDA_CODEC_NVHDMI=y
> >> CONFIG_SND_HDA_CODEC_INTELHDMI=y
> >> CONFIG_SND_HDA_ELD=y
> >> CONFIG_SND_HDA_CODEC_CONEXANT=y
> >> CONFIG_SND_HDA_CODEC_CMEDIA=y
> >> CONFIG_SND_HDA_CODEC_SI3054=y
> >> CONFIG_SND_HDA_GENERIC=y
> >> CONFIG_SND_HDA_POWER_SAVE=y
> >> CONFIG_SND_HDA_POWER_SAVE_DEFAULT=0
> >> CONFIG_SND_HDSP=m
> >> CONFIG_SND_HDSPM=m
> >> CONFIG_SND_HIFIER=m
> >> CONFIG_SND_ICE1712=m
> >> CONFIG_SND_ICE1724=m
> >> CONFIG_SND_INTEL8X0=m
> >> CONFIG_SND_INTEL8X0M=m
> >> CONFIG_SND_KORG1212=m
> >> CONFIG_SND_MAESTRO3=m
> >> CONFIG_SND_MIXART=m
> >> CONFIG_SND_NM256=m
> >> CONFIG_SND_PCXHR=m
> >> CONFIG_SND_RIPTIDE=m
> >> CONFIG_SND_RME32=m
> >> CONFIG_SND_RME96=m
> >> CONFIG_SND_RME9652=m
> >> CONFIG_SND_SONICVIBES=m
> >> CONFIG_SND_TRIDENT=m
> >> CONFIG_SND_VIA82XX=m
> >> CONFIG_SND_VIA82XX_MODEM=m
> >> CONFIG_SND_VIRTUOSO=m
> >> CONFIG_SND_VX222=m
> >> CONFIG_SND_YMFPCI=m
> >> CONFIG_SND_SPI=y
> >> CONFIG_SND_USB=y
> >> CONFIG_SND_USB_AUDIO=m
> >> CONFIG_SND_USB_USX2Y=m
> >> CONFIG_SND_USB_CAIAQ=m
> >> CONFIG_SND_USB_CAIAQ_INPUT=y
> >> CONFIG_SND_USB_US122L=m
> >> CONFIG_SND_PCMCIA=y
> >> CONFIG_SND_VXPOCKET=m
> >> CONFIG_SND_PDAUDIOCF=m
> >> # CONFIG_SND_SOC is not set
> >> _______________________________________________
> >> Linux-audio-dev mailing list
> >> Linux-audio-dev@...
> >> http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
> >>
> >>     
> >
> >
> >       
> >   
>
> -- Secret of Tux: http://images.wallaceandgromit.com/user_uploads/forum_thumbnails/5/75/355.jpg
> "Gromit bit me" says HMV dog: http://img.dailymail.co.uk/i/pix/2007/03_03/GomitHMVPA_468x319.jpg
>
>

     
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[Emanuel Rumpf-2]

2009/11/7 James Warden <warjamy@...>:
>
> You can read more at
> http://en.wikipedia.org/wiki/High_Precision_Event_Timer
>

Thanks for your interrest.

I found some kernel docu:
http://www.mjmwired.net/kernel/Documentation/timers/

And:
http://lwn.net/Articles/167897/


Looks like HPET and RTC are hardware devices, where HPET is meant
to be superior and replace the RTC.

I still don't get: What is the HR-timer ?
I mean how does it compare to the HPET ?
When to decide for the HPET, when for the HRT  api ?
Does one if it depend on the other ?

The kernel-devs seem to distinguish between "high-resolution clock" (=hpet ??)
and HR-timer :
   " We used the high-resolution clock subsystem ontop of hrtimers to verify
152 the hrtimer implementation details in praxis ... "



--
E.R.
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[Paul Davis]

On Sat, Nov 7, 2009 at 2:51 PM, Emanuel Rumpf <xbran@...> wrote:

> Looks like HPET and RTC are hardware devices, where HPET is meant
> to be superior and replace the RTC.

correct, to a large extent.

> I still don't get: What is the HR-timer ?
> I mean how does it compare to the HPET ?
> When to decide for the HPET, when for the HRT  api ?
> Does one if it depend on the other ?

Modern motherboads come with timers that are capable of massively
higher precision than older ones, and allow for very precise
scheduling of timer interrupts quite along time in advance of the
timer going off. The existence of this kind of capability can be used
to implement system scheduling in some moderately different ways.

HR-Timer is the name given to some kernel patches (now in the
mainstream kernel) that allowed the use of this timing hardware. The
changes were a mix of new code that deals with the new capabilities,
and patches that reimplement the existing system timer/scheduling
design using the new hardware.

So, HR-Timer (patches/code/design) requires a high res clock (like HPET).

Note that one of the possible ways to use the HR Time infrastructure
is to go totally tickless. In this design, the kernel is no longer
woken at fixed, regular intervals as has been the case for the entire
history of Linux. Instead, the kernel constantly adds new deadline
times which, when expired, generate an interrupt. In the very, very
unlikely case of there being only one process that is runnable, you
can it without any timer deadlines at all (until some other process
becomes runnable). Obviously, its rather complex, but also totally
awesome stuff. This is separate from HR-Timer, but relies upon it, and
it generally referred to as a "tickless kernel".

the HR-Timer infrastructure is a MUCH better basis for scheduling
MIDI. Even with RTC=10000 (10^4), you still don't have a clock that is
running in sync with the nominal MIDI data rate. with HR-Timer in
place, you can actually schedule the delivery of MIDI bytes precisely
on time ("wake me up in another 0.3msecs") and not rely on a
metronomic tick like RTC.
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[Ralf Mardorf]

Summarized:

I guess my mobo supports hpet :).

$ dmesg | grep -i hpet
[    0.000000] ACPI: HPET 77EE89C0, 0038 (r1 ATI    ASUSACPI 42302E31
AWRD       98)
[    0.000000] ACPI: HPET id: 0x8200 base: 0xfed00000
[    0.000999] hpet clockevent registered
[    0.000999] HPET: 4 timers in total, 0 timers will be used for
per-cpu timer
[    0.177117] hpet0: at MMIO 0xfed00000, IRQs 2, 8, 0, 0
[    0.177123] hpet0: 4 comparators, 32-bit 14.318180 MHz counter
[    1.166497] rtc0: alarms up to one month, 242 bytes nvram, hpet irqs

1. The kernel has to support it too.
2. If the kernel-rt does support it, I need to add a startup script:

    chgrp audio /dev/hpet
    echo 1024 > /proc/sys/dev/hpet/max-user-freq
    modprobe snd-hrtimer
     

Here I don't understand what the value 1024, written to max-user-freq
does mean ;).

3. I need to launch JACK2 with the option "-c", e.g.:

jackd -Rc h -dalsa -dhw:0 -r96000 -p512 -n2 -Xseq

4. The sequencer timing source needs to be set up to hpet or hrtimer too?
rosegarden -v 1.7.3 and qtractor -v 0.4.3.1418 aren't able to do it?

Or will the "-c" option for JACK2 replace a chosen timer for Qtractor or
Rosegarden with hpet?

---

"With a Linux kernel, you need the newer "rtc-cmos" hardware clock
device driver rather than the original "rtc" driver."
(http://en.wikipedia.org/wiki/High_Precision_Event_Timer)

I guess this is within the vanilla kernel source code?!

Cheers,
Ralf
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[James Warden]

Ralph,

As I said, this startup script is something I wrote a long time ago. The max-user-freq is for apps like video players, some polling frequency for improving the playback performance (smoother playback). The default used to be 64Hz. Increasing it to 1024 was making mplayer or xine much more performant.

Actually, I will reboot my DAW when I have some spare time without this startup script (except for the /dev/hpet group permission) and see what the newer kernel sets as default.

J.

--- On Sat, 11/7/09, Ralf Mardorf <ralf.mardorf@...> wrote:

> From: Ralf Mardorf <ralf.mardorf@...>
> Subject: Re: [LAD] timers
> To: "Paul Davis" <paul@...>, "Emanuel Rumpf" <xbran@...>, "James Warden" <warjamy@...>
> Cc: linux-audio-dev@...
> Date: Saturday, November 7, 2009, 4:40 PM
> Summarized:
>
> I guess my mobo supports hpet :).
>
> $ dmesg | grep -i hpet
> [    0.000000] ACPI: HPET 77EE89C0, 0038 (r1
> ATI    ASUSACPI 42302E31 AWRD   
>    98)
> [    0.000000] ACPI: HPET id: 0x8200 base:
> 0xfed00000
> [    0.000999] hpet clockevent registered
> [    0.000999] HPET: 4 timers in total, 0 timers
> will be used for per-cpu timer
> [    0.177117] hpet0: at MMIO 0xfed00000, IRQs 2,
> 8, 0, 0
> [    0.177123] hpet0: 4 comparators, 32-bit
> 14.318180 MHz counter
> [    1.166497] rtc0: alarms up to one month, 242
> bytes nvram, hpet irqs
>
> 1. The kernel has to support it too.
> 2. If the kernel-rt does support it, I need to add a
> startup script:
>
>    chgrp audio /dev/hpet
>    echo 1024 >
> /proc/sys/dev/hpet/max-user-freq
>    modprobe snd-hrtimer
>      
> Here I don't understand what the value 1024, written to
> max-user-freq does mean ;).
>
> 3. I need to launch JACK2 with the option "-c", e.g.:
>
> jackd -Rc h -dalsa -dhw:0 -r96000 -p512 -n2 -Xseq
>
> 4. The sequencer timing source needs to be set up to hpet
> or hrtimer too?
> rosegarden -v 1.7.3 and qtractor -v 0.4.3.1418 aren't able
> to do it?
>
> Or will the "-c" option for JACK2 replace a chosen timer
> for Qtractor or Rosegarden with hpet?
>
> ---
>
> "With a Linux kernel, you need the newer "rtc-cmos"
> hardware clock device driver rather than the original "rtc"
> driver." (http://en.wikipedia.org/wiki/High_Precision_Event_Timer)
>
> I guess this is within the vanilla kernel source code?!
>
> Cheers,
> Ralf
>

     
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[Adrian Knoth]

On Sat, Nov 07, 2009 at 02:42:56PM +0100, Ralf Mardorf wrote:

> spinymouse-sudo@64studio:~$ ll /dev/hpet
> bash: ll: command not found

See below.

> spinymouse-sudo@64studio:~$ ls /dev | grep hpet
> hpet

Useless Use Of Pipe.

> spinymouse-sudo@64studio:~$ cat /boot/config-2.6.29-1-multimedia-amd64 |
> grep CONFIG_SND

Useless Use Of Cat.[0]



Why is it that you constantly prove your lack of knowledge on LAD? Looks
like you don't even know the most basic UNIX commands. That is:

adi@chopin:~$ ls -l /dev/hpet
crw-rw---- 1 root root 10, 228 Nov  7 16:03 /dev/hpet

"ll" has historically been an alias for "ls -l" on some systems, let's
say SuSE 4.x ;)

I suggest you check what the "D" in "LAD" stands for and ask yourself if
this is really the right audience for your Linux n00b questions.


HTH


[0] http://en.wikipedia.org/wiki/Cat_%28Unix%29#Useless_use_of_cat

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[Ray Rashif]

2009/11/8 Adrian Knoth <adi@...>

On Sat, Nov 07, 2009 at 02:42:56PM +0100, Ralf Mardorf wrote:

> spinymouse-sudo@64studio:~$ ll /dev/hpet
> bash: ll: command not found

See below.

> spinymouse-sudo@64studio:~$ ls /dev | grep hpet
> hpet

Useless Use Of Pipe.

> spinymouse-sudo@64studio:~$ cat /boot/config-2.6.29-1-multimedia-amd64 |
> grep CONFIG_SND

Useless Use Of Cat.[0]



Why is it that you constantly prove your lack of knowledge on LAD? Looks
like you don't even know the most basic UNIX commands. That is:

adi@chopin:~$ ls -l /dev/hpet
crw-rw---- 1 root root 10, 228 Nov  7 16:03 /dev/hpet

"ll" has historically been an alias for "ls -l" on some systems, let's
say SuSE 4.x ;)

I suggest you check what the "D" in "LAD" stands for and ask yourself if
this is really the right audience for your Linux n00b questions.


HTH


[0] http://en.wikipedia.org/wiki/Cat_%28Unix%29#Useless_use_of_cat

Holy shit, wait, is that one a demonstration of a "useless use of reply in e-mail"? Good one!

People should _never_ post aliases. What SuSE or corporationX/distributionY does is their useless business, and customers/users should never bring the resulting useless habits outside.

There are countless users on this and related lists (there is no way to bar them from subscribing) who possess such useless knowledge, maybe we should start crucifying them for being uselessly inferior?

Oh wait, sorry. Ignore this (yet another useless) reply!

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[Ray Rashif]

2009/11/8 Ray Rashif <schivmeister@...>

2009/11/8 Adrian Knoth <adi@...>

On Sat, Nov 07, 2009 at 02:42:56PM +0100, Ralf Mardorf wrote:

> spinymouse-sudo@64studio:~$ ll /dev/hpet
> bash: ll: command not found

See below.

> spinymouse-sudo@64studio:~$ ls /dev | grep hpet
> hpet

Useless Use Of Pipe.

> spinymouse-sudo@64studio:~$ cat /boot/config-2.6.29-1-multimedia-amd64 |
> grep CONFIG_SND

Useless Use Of Cat.[0]



Why is it that you constantly prove your lack of knowledge on LAD? Looks
like you don't even know the most basic UNIX commands. That is:

adi@chopin:~$ ls -l /dev/hpet
crw-rw---- 1 root root 10, 228 Nov  7 16:03 /dev/hpet

"ll" has historically been an alias for "ls -l" on some systems, let's
say SuSE 4.x ;)

I suggest you check what the "D" in "LAD" stands for and ask yourself if
this is really the right audience for your Linux n00b questions.


HTH


[0] http://en.wikipedia.org/wiki/Cat_%28Unix%29#Useless_use_of_cat

Holy shit, wait, is that one a demonstration of a "useless use of reply in e-mail"? Good one!

People should _never_ post aliases. What SuSE or corporationX/distributionY does is their useless business, and customers/users should never bring the resulting useless habits outside.

There are countless users on this and related lists (there is no way to bar them from subscribing) who possess such useless knowledge, maybe we should start crucifying them for being uselessly inferior?

Oh wait, sorry. Ignore this (yet another useless) reply!

On a serious note, someone has got to enforce a way to stop topics like these from being posted to LAD. Some kind of warning at http://linuxaudio.org/mailarchive/ should suffice, I think.

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Linux-audio-dev mailing list
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