Thanks for answering (maybe i could have asked on the linuxmao.org forum
too ;) ) .
I tried to change the rtirq script but it doesn't seem to make any
difference. But while looking at the rt priorities, i noticed that the
highest priority for usb was given to the irq 16 and cat /proc/interrupts
tells me that on irq 16 there's uhci_hcd:usb3 and NVIDIA !!!
When i plug my usb soundcard , it's always on irq 20.
So it looks like the highest priority is given to the graphics card .
Is this the problem to solve ?
Flo
> 2008/1/22, hitmuri@xxxxxxxxxx <hitmuri@xxxxxxxxxx>:
>>
>> Hi everyone,
>>
>> i have posted this on the planet ccrma list before, but i don't think
>> it's
>> a distribution problem. I get xruns when using a m-audio fast track pro
>> usb soundcard at 44100Hz, frames/period=64 (same with 128, i need low
>> latency) ,periods/buffer=2 with my new laptop when i have for example
>> freewheeling, tapeutape and jack-rack running (xruns seem to appear when
>> the dsp load rises, i've got none when using tapeutape alone for
>> example).
>> Some of them were related to the latest ccrma kernel, and they
>> disappeared
>> with a previous one. For the other ones, i have 4 ideas :
>>
>> 1) latency timer :
>> doing lspci, all the latencies show 0 , even when i set them to antoher
>> value with setpci. But with dmesg, i can see that at startup they are
>> set
>> to 64.
>> Fernando Lopez-Lezcano told me that on some hardware latency timer
>> couldn't be changed and that 64 could be enough actually.
>> (forgot to say that the usb irq isn't shared)
>>
>> So it looks like i can't do anything for that.
>>
>> 2) rtc :
>> At startup i have a message from udev : Node Symlink... node /dev/rtc
>> already exists , link to /dev/rtc0 will not overwrite it.
>
>
>
> I got this message too, but I don't know if there is any impact on the
> sound
> system.
>
> 3) soundcard power
>> The fast track pro can be powered by usb or by an external power supply.
>> Mine is usb powered for now. Is this a problem ?
>>
>> 4) rtirq
>> I noticed that in the rtirq script , i have these lines:
>> RTIRQ_NAME_LIST="rtc snd usb i8042"
>> RTIRQ_NON_THREADED="rtc snd"
>> Do they need to be changed when using a usb soundcard ?
>
>
> If your sound card works with USB, you can write this :
>
> RTIRQ_NAME_LIST="rtc usb i8042"
> RTIRQ_NON_THREADED="rtc usb"
>
>
> Then you restart the script and echo his status
>
> $ sudo /etc/init.d/rtirq restart
> $ /etc/init.d/rtirq status
>
> You will see the priority on each IRQ. Then you have to connect your sound
> card on the USB port wich has the best priority.
>
>
> If anyone has an idea on that...
>>
>> Sorry it was quite long !!
>>
>> Thanks
>>
>> Flo
>
>
> Hope this help you,
> cheers,
>
> Mysth-R
>
>
> --
> *
> ***************************************************************************************
> * {^_^} Mysth-R {^_^}
> *
> * http://myspace.com/mysthr
> * http://myspace.com/aideauditive
> * http://mysthr.free.fr => Site dédié à l'audio sous Fedora/PlanetCCRMA.
> *
> ***************************************************************************************
>
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