[ALSA] pcm-midlevel: Add more strict buffer position checks based on jiffies
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>
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index fbb2e39..63d088f 100644
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -209,9 +209,11 @@
{
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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;
}