From e7373b702f6eab35f315e016a4159860a7a4d686 Mon Sep 17 00:00:00 2001 From: Clemens Ladisch Date: Tue, 10 Nov 2009 10:13:30 +0100 Subject: [PATCH] sound: pcm: record a substream's owner process Record the pid of the task that opened a PCM substream. For sound cards with hardware mixing, this allows determining which process is associated with a specific substream's volume control. Signed-off-by: Clemens Ladisch Signed-off-by: Takashi Iwai --- include/sound/pcm.h | 3 +++ sound/core/pcm.c | 4 ++++ 2 files changed, 7 insertions(+) diff --git a/include/sound/pcm.h b/include/sound/pcm.h index de6d981de5d6..c83a4a79f16b 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -348,6 +348,8 @@ struct snd_pcm_group { /* keep linked substreams */ int count; }; +struct pid; + struct snd_pcm_substream { struct snd_pcm *pcm; struct snd_pcm_str *pstr; @@ -379,6 +381,7 @@ struct snd_pcm_substream { atomic_t mmap_count; unsigned int f_flags; void (*pcm_release)(struct snd_pcm_substream *); + struct pid *pid; #if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE) /* -- OSS things -- */ struct snd_pcm_oss_substream oss; diff --git a/sound/core/pcm.c b/sound/core/pcm.c index 8e2c7833614c..6884ae031f6f 100644 --- a/sound/core/pcm.c +++ b/sound/core/pcm.c @@ -435,6 +435,7 @@ static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry, return; } snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state)); + snd_iprintf(buffer, "owner_pid : %d\n", pid_vnr(substream->pid)); snd_iprintf(buffer, "trigger_time: %ld.%09ld\n", status.trigger_tstamp.tv_sec, status.trigger_tstamp.tv_nsec); snd_iprintf(buffer, "tstamp : %ld.%09ld\n", @@ -900,6 +901,7 @@ int snd_pcm_attach_substream(struct snd_pcm *pcm, int stream, substream->private_data = pcm->private_data; substream->ref_count = 1; substream->f_flags = file->f_flags; + substream->pid = get_pid(task_pid(current)); pstr->substream_opened++; *rsubstream = substream; return 0; @@ -921,6 +923,8 @@ void snd_pcm_detach_substream(struct snd_pcm_substream *substream) kfree(runtime->hw_constraints.rules); kfree(runtime); substream->runtime = NULL; + put_pid(substream->pid); + substream->pid = NULL; substream->pstr->substream_opened--; } -- 2.39.2