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[ALSA] pcm-midlevel: Add more strict buffer position checks based on jiffies

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Some drivers like Intel8x0 or Intel HDA are broken for some hardware variants.
This patch adds more strict buffer position checks based on jiffies when
internal hw_ptr is updated. Enable xrun_debug to see mangling of wrong
positions.

As a side effect, the hw_ptr interrupt update routine might do slightly better
job when many interrupts are lost.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
This commit is contained in:
Jaroslav Kysela 2009-04-10 12:28:58 +02:00
parent fa00e046b4
commit bbf6ad1399
2 changed files with 41 additions and 9 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
include/sound/pcm.h
View file

@ -268,7 +268,8 @@ struct snd_pcm_runtime {
int overrange;
snd_pcm_uframes_t avail_max;
snd_pcm_uframes_t hw_ptr_base; /* Position at buffer restart */
snd_pcm_uframes_t hw_ptr_interrupt; /* Position at interrupt time*/
snd_pcm_uframes_t hw_ptr_interrupt; /* Position at interrupt time */
unsigned long hw_ptr_jiffies; /* Time when hw_ptr is updated */
/* -- HW params -- */
snd_pcm_access_t access; /* access mode */

47
sound/core/pcm_lib.c
View file

@ -209,9 +209,11 @@ static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
snd_pcm_uframes_t pos;
snd_pcm_uframes_t new_hw_ptr, hw_ptr_interrupt, hw_base;
snd_pcm_sframes_t delta;
snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_ptr_interrupt, hw_base;
snd_pcm_sframes_t hdelta, delta;
unsigned long jdelta;
old_hw_ptr = runtime->status->hw_ptr;
pos = snd_pcm_update_hw_ptr_pos(substream, runtime);
if (pos == SNDRV_PCM_POS_XRUN) {
xrun(substream);
@ -247,7 +249,30 @@ static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream)
new_hw_ptr = hw_base + pos;
}
}
if (delta > runtime->period_size) {
hdelta = new_hw_ptr - old_hw_ptr;
jdelta = jiffies - runtime->hw_ptr_jiffies;
if (((hdelta * HZ) / runtime->rate) > jdelta + HZ/100) {
delta = jdelta /
(((runtime->period_size * HZ) / runtime->rate)
+ HZ/100);
hw_ptr_error(substream,
"hw_ptr skipping! [Q] "
"(pos=%ld, delta=%ld, period=%ld, "
"jdelta=%lu/%lu/%lu)\n",
(long)pos, (long)hdelta,
(long)runtime->period_size, jdelta,
((hdelta * HZ) / runtime->rate), delta);
hw_ptr_interrupt = runtime->hw_ptr_interrupt +
runtime->period_size * delta;
if (hw_ptr_interrupt >= runtime->boundary)
hw_ptr_interrupt -= runtime->boundary;
/* rebase to interrupt position */
hw_base = new_hw_ptr = hw_ptr_interrupt;
/* align hw_base to buffer_size */
hw_base -= hw_base % runtime->buffer_size;
delta = 0;
}
if (delta > runtime->period_size + runtime->period_size / 2) {
hw_ptr_error(substream,
"Lost interrupts? "
"(stream=%i, delta=%ld, intr_ptr=%ld)\n",
@ -263,6 +288,7 @@ static int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream)
runtime->hw_ptr_base = hw_base;
runtime->status->hw_ptr = new_hw_ptr;
runtime->hw_ptr_jiffies = jiffies;
runtime->hw_ptr_interrupt = hw_ptr_interrupt;
return snd_pcm_update_hw_ptr_post(substream, runtime);
@ -275,6 +301,7 @@ int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
snd_pcm_uframes_t pos;
snd_pcm_uframes_t old_hw_ptr, new_hw_ptr, hw_base;
snd_pcm_sframes_t delta;
unsigned long jdelta;
old_hw_ptr = runtime->status->hw_ptr;
pos = snd_pcm_update_hw_ptr_pos(substream, runtime);
@ -286,14 +313,15 @@ int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
new_hw_ptr = hw_base + pos;
delta = new_hw_ptr - old_hw_ptr;
jdelta = jiffies - runtime->hw_ptr_jiffies;
if (delta < 0) {
delta += runtime->buffer_size;
if (delta < 0) {
hw_ptr_error(substream,
"Unexpected hw_pointer value [2] "
"(stream=%i, pos=%ld, old_ptr=%ld)\n",
"(stream=%i, pos=%ld, old_ptr=%ld, jdelta=%li)\n",
substream->stream, (long)pos,
(long)old_hw_ptr);
(long)old_hw_ptr, jdelta);
return 0;
}
hw_base += runtime->buffer_size;
@ -301,12 +329,13 @@ int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
hw_base = 0;
new_hw_ptr = hw_base + pos;
}
if (delta > runtime->period_size && runtime->periods > 1) {
if (((delta * HZ) / runtime->rate) > jdelta + HZ/100) {
hw_ptr_error(substream,
"hw_ptr skipping! "
"(pos=%ld, delta=%ld, period=%ld)\n",
"(pos=%ld, delta=%ld, period=%ld, jdelta=%lu/%lu)\n",
(long)pos, (long)delta,
(long)runtime->period_size);
(long)runtime->period_size, jdelta,
((delta * HZ) / runtime->rate));
return 0;
}
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
@ -315,6 +344,7 @@ int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream)
runtime->hw_ptr_base = hw_base;
runtime->status->hw_ptr = new_hw_ptr;
runtime->hw_ptr_jiffies = jiffies;
return snd_pcm_update_hw_ptr_post(substream, runtime);
}
@ -1441,6 +1471,7 @@ 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;
}