On Tuesday 03 Mar 2009 17:41:22 Takashi Iwai wrote: > > Hrm, but still an unexpected jump is found. > > > > If you build the driver with CONFIG_SND_PCM_XRUN_DEBUG=y, you must > > have /proc/asound/card0/pcm0p/xrun_debug. Echo 1 to this (as root) > > echo 1 > /proc/asound/card0/pcm0p/xrun_debug > > and try the program, see whether any debug message appears. > > If any message appears, it means basically an unstable hardware. > > > > Also, the below is a patch I tried to clean up and improve the > > handling. Give it a try (and do echo 1 above for testing). > > BTW, the original test program is very hard to see what's wrong > because it spews out way too many lines. The below is a filtered-out > version. > > It prints only unexpected jumps of avail values (the threshold is > set 100 blindly). The output is like below: > > % ./alsa-time-test hw > 21720872 (4987) delta 216 avail 216 delay 4200 > 21943118 (65) delta 208 avail 208 delay 4208 > 23752310 (3) delta 232 avail 232 delay 4184 > 23761847 (5972) delta 264 avail 264 delay 4152 > > The first column is the usec from the program start, the next value in > parentheses is the time-step from the last time of status changes, > the delta is the increase of avail, and the rest are raw values. > > If a too large delta appears in a short time-step, something is wrong. > If it appears in a large time-step, it's simply a wrong responsiveness > (aka system latency). Hello Takashi/Lennart, Sorry, I have been busy for a few days. I patched my kernel (kernel-2.6.29-0.53.rc7.fc10.x86_64) with your pcm_lib.c patch and 'echo 1 > /proc/asound/card0/pcm0p/xrun_debug'. I have done several runs with the new alsa-time-test.c code. Typically I get a bunch of kernel dmesg when I start the alsa-time-test program but not afterwards. Just a reminder - I'm running this on fast hardware - X58 / Core i7 920 - the machine is not loaded at all, so latency should be very low. snd_hda_intel - ' 00-00: AD198x Analog : AD198x Analog : playback 1 : capture 3'. Here is an example run ..... hw_ptr skipping! (pos=2096, delta=2096, period=1472) hw_ptr skipping! (pos=2096, delta=2096, period=1472) hw_ptr skipping! (pos=3600, delta=3600, period=1472) hw_ptr skipping! (pos=3600, delta=3600, period=1472) hw_ptr skipping! (pos=3600, delta=3600, period=1472) hw_ptr skipping! (pos=3600, delta=3600, period=1472) hw_ptr skipping! (pos=3600, delta=3600, period=1472) hw_ptr skipping! (pos=3600, delta=3600, period=1472) 9901323 (2632) delta 111 avail 117 delay 4299 19901290 (2599) delta 112 avail 112 delay 4304 29901285 (3) delta 112 avail 112 delay 4304 39901315 (2624) delta 120 avail 120 delay 4296 49901317 (2626) delta 112 avail 112 delay 4304 59901317 (2625) delta 112 avail 112 delay 4304 69901323 (2632) delta 118 avail 118 delay 4298 79901391 (3) delta 120 avail 120 delay 4296 89901327 (2634) delta 112 avail 112 delay 4304 99901283 (2591) delta 120 avail 120 delay 4296 109901334 (2642) delta 120 avail 120 delay 4296 119901320 (2627) delta 112 avail 112 delay 4304 Regards Clive -- Clive Messer <clive@xxxxxxxxxxxxxxxxx> _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
