From 6af3fb72d2437239e5eb13a59e95dc43ccab3e8f Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 27 May 2009 10:49:26 +0200 Subject: ALSA: Fix invalid jiffies check after pause The hw_ptr_jiffies has to be reset properly to avoid the invalid check of jiffies delta in snd_pcm_update_hw_ptr*() functions. Especailly this patch fixes the bogus jiffies check after the puase and resume. This patch is a modified version of the original patch by Jaroslav. Signed-off-by: Takashi Iwai --- sound/core/pcm_lib.c | 1 - sound/core/pcm_native.c | 6 ++++++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index a2a792c18c4..3eea98a4e65 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -1478,7 +1478,6 @@ static int snd_pcm_lib_ioctl_reset(struct snd_pcm_substream *substream, runtime->status->hw_ptr %= runtime->buffer_size; else runtime->status->hw_ptr = 0; - runtime->hw_ptr_jiffies = jiffies; snd_pcm_stream_unlock_irqrestore(substream, flags); return 0; } diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index fc6f98e257d..b5da656d1ec 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -848,6 +848,7 @@ static void snd_pcm_post_start(struct snd_pcm_substream *substream, int state) { struct snd_pcm_runtime *runtime = substream->runtime; snd_pcm_trigger_tstamp(substream); + runtime->hw_ptr_jiffies = jiffies; runtime->status->state = state; if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK && runtime->silence_size > 0) @@ -961,6 +962,11 @@ static int snd_pcm_do_pause(struct snd_pcm_substream *substream, int push) { if (substream->runtime->trigger_master != substream) return 0; + /* The jiffies check in snd_pcm_update_hw_ptr*() is done by + * a delta betwen the current jiffies, this gives a large enough + * delta, effectively to skip the check once. + */ + substream->runtime->hw_ptr_jiffies = jiffies - HZ * 1000; return substream->ops->trigger(substream, push ? SNDRV_PCM_TRIGGER_PAUSE_PUSH : SNDRV_PCM_TRIGGER_PAUSE_RELEASE); -- cgit v1.2.3 From c87d9732004b3f8fd82d729f12ccfb96c0df279e Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 27 May 2009 10:53:33 +0200 Subject: ALSA: Enable PCM hw_ptr_jiffies check only in xrun_debug mode The PCM hw_ptr jiffies check results sometimes in problems when a hardware doesn't give smooth hw_ptr updates. So far, au88x0 and some other drivers appear not working due to this strict check. However, this check is a nice debug tool, and the capability should be still kept. Hence, we disable this check now as default unless the user enables it by setting the xrun_debug mode to the specific stream via a proc file. Signed-off-by: Takashi Iwai --- Documentation/sound/alsa/Procfile.txt | 5 +++++ sound/core/pcm_lib.c | 9 ++++++++- 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/Documentation/sound/alsa/Procfile.txt b/Documentation/sound/alsa/Procfile.txt index bba2dbb79d8..cfac20cf9e3 100644 --- a/Documentation/sound/alsa/Procfile.txt +++ b/Documentation/sound/alsa/Procfile.txt @@ -104,6 +104,11 @@ card*/pcm*/xrun_debug When this value is greater than 1, the driver will show the stack trace additionally. This may help the debugging. + Since 2.6.30, this option also enables the hwptr check using + jiffies. This detects spontaneous invalid pointer callback + values, but can be lead to too much corrections for a (mostly + buggy) hardware that doesn't give smooth pointer updates. + card*/pcm*/sub*/info The general information of this PCM sub-stream. diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index 3eea98a4e65..d659995ac3a 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -249,6 +249,11 @@ static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream) new_hw_ptr = hw_base + pos; } } + + /* Do jiffies check only in xrun_debug mode */ + if (!xrun_debug(substream)) + goto no_jiffies_check; + /* Skip the jiffies check for hardwares with BATCH flag. * Such hardware usually just increases the position at each IRQ, * thus it can't give any strange position. @@ -336,7 +341,9 @@ int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream) hw_base = 0; new_hw_ptr = hw_base + pos; } - if (((delta * HZ) / runtime->rate) > jdelta + HZ/100) { + /* Do jiffies check only in xrun_debug mode */ + if (xrun_debug(substream) && + ((delta * HZ) / runtime->rate) > jdelta + HZ/100) { hw_ptr_error(substream, "hw_ptr skipping! " "(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu)\n", -- cgit v1.2.3