Hi there
Okay, I had time today to test a bit more on what was going on
On 13 February 2012 00:17, Anssi Hannula anssi.hannula@iki.fi wrote:
I'm not familiar enough with HDA to comment on the cause of the issue, but out of interest, does the hang really only happen with passthrough, i.e. (AES0 & 0x02) set, or does it happen with a PCM stream with the same parameters as well (and the application(s) just happen to set problematic ALSA parameters only in passthrough mode)?
Actually, went through over a lot of different type, only to find that the problem isn't with passthrough as such, but a combination of the prealloc value set and if 16 bits / 32 bits audio.
16 bits audio, as soon as the ALSA hardware buffer is set to something different than the default 64 (like 4096, the default when using Ubuntu) snd_pcm_write will hang then error.
32 bits audio, plays under most combinations tried, except for 5.1 PCM where I had to set the prealloc buffer to 1024 and above to get it work
Here are the various mode I tried, the output of the log is for 4096 prealloc buffer
For a reminder: format=2 -> SND_PCM_FORMAT_S16_LE format=10 -> SND_PCM_FORMAT_S32_LE
AC3 Passthrough: working for 64kB, Not working for: 128, 256, 512, 1024, 2048 and 4096 2012-02-13 15:58:50.339376 I ALSA: SetParameters(format=2, channels=2, rate=48000, buffer_time=500000, period_time=4) 2012-02-13 15:58:50.339437 I ALSA: Buffer size range from 64 to 1048576 2012-02-13 15:58:50.339441 I ALSA: Period size range from 32 to 524288 2012-02-13 15:58:50.339455 I ALSA: Buffer time = 500000 us 2012-02-13 15:58:50.339465 I ALSA: Period time = 4 periods 2012-02-13 15:58:50.458098 I ALSA: Buffer size = 24000 | Period size = 6000 2012-02-13 15:58:50.696838 I AO: Audio fragment size: 12000
16 bits stereo: working for 64, Not working for: 128, 256, 512, 1024, 2048, 4096 2012-02-13 16:20:39.027793 I ALSA: SetParameters(format=2, channels=2, rate=48000, buffer_time=500000, period_time=4) 2012-02-13 16:20:39.027855 I ALSA: Buffer size range from 64 to 1048576 2012-02-13 16:20:39.027859 I ALSA: Period size range from 32 to 524288 2012-02-13 16:20:39.027873 I ALSA: Buffer time = 500000 us 2012-02-13 16:20:39.027883 I ALSA: Period time = 4 periods 2012-02-13 16:20:39.267237 I ALSA: Buffer size = 24000 | Period size = 6000 2012-02-13 16:20:39.507467 I AO: Audio fragment size: 12000
32 bits Stereo: working for: 64, 128,,256, 512, 1024, 2048 and 4096 2012-02-13 16:05:25.010312 I ALSA: SetParameters(format=10, channels=2, rate=48000, buffer_time=500000, period_time=4) 2012-02-13 16:05:25.010372 I ALSA: Buffer size range from 32 to 524288 2012-02-13 16:05:25.010376 I ALSA: Period size range from 16 to 262144 2012-02-13 16:05:25.010389 I ALSA: Buffer time = 500000 us 2012-02-13 16:05:25.010400 I ALSA: Period time = 4 periods 2012-02-13 16:05:25.286857 I ALSA: Buffer size = 24000 | Period size = 6000 2012-02-13 16:05:25.526849 I AO: Audio fragment size: 24000
5.1 16 bits PCM: Using 64kB prealloc buffer, snd_pcm_hw_params_set_buffer_time_near gives the error "Invalid Parameter" for 500000 Not working for 128, 256, 512, 1024, 2048 and 4096
2012-02-13 16:09:11.621562 I ALSA: SetParameters(format=2, channels=6, rate=48000, buffer_time=500000, period_time=4) 2012-02-13 16:09:11.621628 I ALSA: Buffer size range from 22 to 349525 2012-02-13 16:09:11.621632 I ALSA: Period size range from 11 to 174762 2012-02-13 16:09:11.621645 I ALSA: Buffer time = 500000 us 2012-02-13 16:09:11.621663 I ALSA: Period time = 4 periods 2012-02-13 16:09:11.796861 I ALSA: Buffer size = 24000 | Period size = 6000 2012-02-13 16:09:12.036842 I AO: Audio fragment size: 36000
5.1 32 bits PCM: Not working for: 64, 256, 512. Working for 1024, 2048, 4096 128 gives Invalid argument for snd_pcm_hw_params_set_buffer_time_near
2012-02-13 16:25:12.890306 I ALSA: SetParameters(format=10, channels=6, rate=48000, buffer_time=500000, period_time=4) 2012-02-13 16:25:12.890366 I ALSA: Buffer size range from 12 to 174762 2012-02-13 16:25:12.890370 I ALSA: Period size range from 6 to 87381 2012-02-13 16:25:12.890383 I ALSA: Buffer time = 500000 us 2012-02-13 16:25:12.890393 I ALSA: Period time = 4 periods 2012-02-13 16:25:13.066855 I ALSA: Buffer size = 24000 | Period size = 6000 2012-02-13 16:25:13.316823 I AO: Audio fragment size: 72000
_From looking at hda_intel.c, it seems that the problem is that the nvidia set AZX_DCAPS_BUFSIZE in driver_caps when it probably doesn't support it.. Hopefully Stephen will be able to answer that one.
I'm surprised not more people has reported the problem, surely there are a lot of people affected by this... Though 1.0.25 is very recent and not used yet by many linux distribution. Soon this will change :(
Jean-Yves