When debugging pcm drivers I found the "period" or "hw" prefix printed by either XRUN_DEBUG_PERIODUPDATE or XRUN_DEBUG_PERIODUPDATE events, respectively to be very useful is observing the interplay between interrupt-context updates and syscall-context updates.
Similarly, when debugging overruns with XRUN_DEBUG_LOG it is useful to see the context of the last 10 positions.
Add an in_interrupt member to hwptr_log_entry which stores the value of the in_interrupt parameter of snd_pcm_update_hw_ptr0 when the log entry is created. Print a "[Q]" prefix when dumping the log entries if in_interrupt was true.
Signed-off-by: Ben Gardiner bengardiner@nanometrics.ca --- sound/core/pcm_lib.c | 12 ++++++++---- 1 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index 64449cb..c8c8091 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -189,6 +189,7 @@ static void xrun(struct snd_pcm_substream *substream) #define XRUN_LOG_CNT 10
struct hwptr_log_entry { + unsigned int in_interrupt; unsigned long jiffies; snd_pcm_uframes_t pos; snd_pcm_uframes_t period_size; @@ -204,7 +205,7 @@ struct snd_pcm_hwptr_log { };
static void xrun_log(struct snd_pcm_substream *substream, - snd_pcm_uframes_t pos) + snd_pcm_uframes_t pos, int in_interrupt) { struct snd_pcm_runtime *runtime = substream->runtime; struct snd_pcm_hwptr_log *log = runtime->hwptr_log; @@ -220,6 +221,7 @@ static void xrun_log(struct snd_pcm_substream *substream, return; } entry = &log->entries[log->idx]; + entry->in_interrupt = in_interrupt; entry->jiffies = jiffies; entry->pos = pos; entry->period_size = runtime->period_size; @@ -246,9 +248,11 @@ static void xrun_log_show(struct snd_pcm_substream *substream) entry = &log->entries[idx]; if (entry->period_size == 0) break; - snd_printd("hwptr log: %s: j=%lu, pos=%ld/%ld/%ld, " + snd_printd("hwptr log: %s: %sj=%lu, pos=%ld/%ld/%ld, " "hwptr=%ld/%ld\n", - name, entry->jiffies, (unsigned long)entry->pos, + name, entry->in_interrupt ? "[Q] " : "", + entry->jiffies, + (unsigned long)entry->pos, (unsigned long)entry->period_size, (unsigned long)entry->buffer_size, (unsigned long)entry->old_hw_ptr, @@ -326,7 +330,7 @@ static int snd_pcm_update_hw_ptr0(struct snd_pcm_substream *substream, } pos -= pos % runtime->min_align; if (xrun_debug(substream, XRUN_DEBUG_LOG)) - xrun_log(substream, pos); + xrun_log(substream, pos, in_interrupt); hw_base = runtime->hw_ptr_base; new_hw_ptr = hw_base + pos; if (in_interrupt) {