ALSA: sound, core, pcm_lib: xrun_log: log also in_interrupt

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>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 8 insertions, 4 deletions

diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index 64449cb8f873..c8c8091f9a71 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) {