Kelly Anderson wrote:

I had a consistent hard-lockup on one of my machines, an Amd X6, just after Kdm loaded the desktop (most certainly when it decides to start talking to the sound card). Everything was dead, even ssh access to the computer. I git bisected it until I found the commit that was causing it. After reverting the patch everything is fine.

commit 59ff878ffb26bc0be812ca8295799164f413ae88 Author: Clemens Ladisch Date: Thu Nov 18 09:43:52 2010 +0100

 ALSA: pcm: detect xruns in no-period-wakeup mode

This looks as if you get an infinite loop, probably because hw_ptr_buffer_jiffies is zero.

Please try this patch:

--- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -425,6 +425,8 @@ static int snd_pcm_hw_params(struct snd_ runtime->no_period_wakeup = (params->info & SNDRV_PCM_INFO_NO_PERIOD_WAKEUP) && (params->flags & SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP); + runtime->hw_ptr_buffer_jiffies = + max(1uL, (runtime->buffer_size * HZ) / runtime->rate);

bits = snd_pcm_format_physical_width(runtime->format); runtime->sample_bits = bits; @@ -866,8 +868,6 @@ static void snd_pcm_post_start(struct sn struct snd_pcm_runtime *runtime = substream->runtime; snd_pcm_trigger_tstamp(substream); runtime->hw_ptr_jiffies = jiffies; - runtime->hw_ptr_buffer_jiffies = (runtime->buffer_size * HZ) / - runtime->rate; runtime->status->state = state; if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK && runtime->silence_size > 0)