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authorTakashi Iwai <tiwai@suse.de>2014-11-04 14:02:40 +0100
committerTakashi Iwai <tiwai@suse.de>2014-11-04 14:09:16 +0100
commit2b30d411dbc6eddfb5b4f9afd5a2c57b6f4dd96c (patch)
tree02f9efaa6a39b5579eb3f708435ef743b2ab4d09
parentf5914908a5b7b2338f210e56827a1ef35585dc6d (diff)
ALSA: pcm: Add xrun_injection proc entry
This patch adds a new proc entry for PCM substreams to inject an XRUN. When a PCM substream is running and any value is written to its xrun_injection proc file, the driver triggers XRUN. This is a useful feature for debugging XRUN and error handling code paths. Note that this entry is enabled only when CONFIG_SND_PCM_XRUN_DEBUG is set. Signed-off-by: Takashi Iwai <tiwai@suse.de>
-rw-r--r--Documentation/sound/alsa/Procfile.txt4
-rw-r--r--include/sound/pcm.h3
-rw-r--r--sound/core/pcm.c33
3 files changed, 40 insertions, 0 deletions
diff --git a/Documentation/sound/alsa/Procfile.txt b/Documentation/sound/alsa/Procfile.txt
index cfc49567b9dc..7f8a0d325905 100644
--- a/Documentation/sound/alsa/Procfile.txt
+++ b/Documentation/sound/alsa/Procfile.txt
@@ -133,6 +133,10 @@ card*/pcm*/sub*/sw_params
card*/pcm*/sub*/prealloc
The buffer pre-allocation information.
+card*/pcm*/sub*/xrun_injection
+ Triggers an XRUN to the running stream when any value is
+ written to this proc file. Used for fault injection.
+ This entry is write-only.
AC97 Codec Information
----------------------
diff --git a/include/sound/pcm.h b/include/sound/pcm.h
index 29eb09ef2969..0b8daeed0a33 100644
--- a/include/sound/pcm.h
+++ b/include/sound/pcm.h
@@ -416,7 +416,10 @@ struct snd_pcm_substream {
struct snd_info_entry *proc_status_entry;
struct snd_info_entry *proc_prealloc_entry;
struct snd_info_entry *proc_prealloc_max_entry;
+#ifdef CONFIG_SND_PCM_XRUN_DEBUG
+ struct snd_info_entry *proc_xrun_injection_entry;
#endif
+#endif /* CONFIG_SND_VERBOSE_PROCFS */
/* misc flags */
unsigned int hw_opened: 1;
};
diff --git a/sound/core/pcm.c b/sound/core/pcm.c
index 31acc3df62cd..8f624b7af0ca 100644
--- a/sound/core/pcm.c
+++ b/sound/core/pcm.c
@@ -483,6 +483,19 @@ static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
}
#ifdef CONFIG_SND_PCM_XRUN_DEBUG
+static void snd_pcm_xrun_injection_write(struct snd_info_entry *entry,
+ struct snd_info_buffer *buffer)
+{
+ struct snd_pcm_substream *substream = entry->private_data;
+ struct snd_pcm_runtime *runtime;
+
+ snd_pcm_stream_lock_irq(substream);
+ runtime = substream->runtime;
+ if (runtime && runtime->status->state == SNDRV_PCM_STATE_RUNNING)
+ snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
+ snd_pcm_stream_unlock_irq(substream);
+}
+
static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
struct snd_info_buffer *buffer)
{
@@ -614,6 +627,22 @@ static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
}
substream->proc_status_entry = entry;
+#ifdef CONFIG_SND_PCM_XRUN_DEBUG
+ entry = snd_info_create_card_entry(card, "xrun_injection",
+ substream->proc_root);
+ if (entry) {
+ entry->private_data = substream;
+ entry->c.text.read = NULL;
+ entry->c.text.write = snd_pcm_xrun_injection_write;
+ entry->mode = S_IFREG | S_IWUSR;
+ if (snd_info_register(entry) < 0) {
+ snd_info_free_entry(entry);
+ entry = NULL;
+ }
+ }
+ substream->proc_xrun_injection_entry = entry;
+#endif /* CONFIG_SND_PCM_XRUN_DEBUG */
+
return 0;
}
@@ -627,6 +656,10 @@ static int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream)
substream->proc_sw_params_entry = NULL;
snd_info_free_entry(substream->proc_status_entry);
substream->proc_status_entry = NULL;
+#ifdef CONFIG_SND_PCM_XRUN_DEBUG
+ snd_info_free_entry(substream->proc_xrun_injection_entry);
+ substream->proc_xrun_injection_entry = NULL;
+#endif
snd_info_free_entry(substream->proc_root);
substream->proc_root = NULL;
return 0;