[LAU] usb soundcard: xruns and latency even with -rt kernel

[Jacob Lee]

On Dec 27, 2007 6:30 PM, Geoff Beasley <songshop at bizmedia.com.au> wrote:
> do you use Rui's rtprio? that should help. Are  the tickless & hpet timers
> enabled  in the kernel ?
>

I hadn't run into rtprio before. It seems to be a relatively blunt
tool for invoking chrt -- in my case, it finds an internal sound card
that I don't care about and also a few other usb-related interrupts
that don't need to be on high priority. It does, though, also increase
the priority of the rtc and i8042 irqs, which I hadn't been doing. So
now I'm (manually) setting rtc highest, followed by the irq for the
usb bus my soundcard is on, followed by the two i8042 interrupts. It
hasn't seemed to help, though.

Here are my HPET and timer settings. They -look- correct to me, though
I'm not really sure what they all mean. Is there anything else I
should look at?

CONFIG_HPET_TIMER=y
CONFIG_HPET_EMULATE_RTC=y
CONFIG_HPET=y
# CONFIG_HPET_RTC_IRQ is not set

CONFIG_NO_HZ=y
# CONFIG_HZ_100 is not set
# CONFIG_HZ_250 is not set
# CONFIG_HZ_300 is not set
CONFIG_HZ_1000=y
CONFIG_HZ=1000
CONFIG_HIGH_RES_TIMERS=y

-- 
Jacob Lee
artdent at gmail.com