diff options
| author | Takashi Iwai <tiwai@suse.de> | 2018-01-08 14:03:53 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-01-17 09:35:26 +0100 |
| commit | fa6c1876ecf724f4bb77842770941db41d35c3f9 (patch) | |
| tree | 84fb0e0c53c2f371693ce2070be8037663e871ad /sound | |
| parent | 9bb4bb18ccffc4dc4a1f1038a5dc0fb3a4020c05 (diff) | |
ALSA: pcm: Allow aborting mutex lock at OSS read/write loops
commit 900498a34a3ac9c611e9b425094c8106bdd7dc1c upstream.
PCM OSS read/write loops keep taking the mutex lock for the whole
read/write, and this might take very long when the exceptionally high
amount of data is given. Also, since it invokes with mutex_lock(),
the concurrent read/write becomes unbreakable.
This patch tries to address these issues by replacing mutex_lock()
with mutex_lock_interruptible(), and also splits / re-takes the lock
at each read/write period chunk, so that it can switch the context
more finely if requested.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/core/oss/pcm_oss.c | 36 |
1 files changed, 21 insertions, 15 deletions
diff --git a/sound/core/oss/pcm_oss.c b/sound/core/oss/pcm_oss.c index d2a9e0fd46b0..494b7b533366 100644 --- a/sound/core/oss/pcm_oss.c +++ b/sound/core/oss/pcm_oss.c @@ -1369,8 +1369,11 @@ static ssize_t snd_pcm_oss_write1(struct snd_pcm_substream *substream, const cha if ((tmp = snd_pcm_oss_make_ready(substream)) < 0) return tmp; - mutex_lock(&runtime->oss.params_lock); while (bytes > 0) { + if (mutex_lock_interruptible(&runtime->oss.params_lock)) { + tmp = -ERESTARTSYS; + break; + } if (bytes < runtime->oss.period_bytes || runtime->oss.buffer_used > 0) { tmp = bytes; if (tmp + runtime->oss.buffer_used > runtime->oss.period_bytes) @@ -1414,18 +1417,18 @@ static ssize_t snd_pcm_oss_write1(struct snd_pcm_substream *substream, const cha xfer += tmp; if ((substream->f_flags & O_NONBLOCK) != 0 && tmp != runtime->oss.period_bytes) - break; + tmp = -EAGAIN; } + err: + mutex_unlock(&runtime->oss.params_lock); + if (tmp < 0) + break; if (signal_pending(current)) { tmp = -ERESTARTSYS; - goto err; + break; } + tmp = 0; } - mutex_unlock(&runtime->oss.params_lock); - return xfer; - - err: - mutex_unlock(&runtime->oss.params_lock); return xfer > 0 ? (snd_pcm_sframes_t)xfer : tmp; } @@ -1473,8 +1476,11 @@ static ssize_t snd_pcm_oss_read1(struct snd_pcm_substream *substream, char __use if ((tmp = snd_pcm_oss_make_ready(substream)) < 0) return tmp; - mutex_lock(&runtime->oss.params_lock); while (bytes > 0) { + if (mutex_lock_interruptible(&runtime->oss.params_lock)) { + tmp = -ERESTARTSYS; + break; + } if (bytes < runtime->oss.period_bytes || runtime->oss.buffer_used > 0) { if (runtime->oss.buffer_used == 0) { tmp = snd_pcm_oss_read2(substream, runtime->oss.buffer, runtime->oss.period_bytes, 1); @@ -1505,16 +1511,16 @@ static ssize_t snd_pcm_oss_read1(struct snd_pcm_substream *substream, char __use bytes -= tmp; xfer += tmp; } + err: + mutex_unlock(&runtime->oss.params_lock); + if (tmp < 0) + break; if (signal_pending(current)) { tmp = -ERESTARTSYS; - goto err; + break; } + tmp = 0; } - mutex_unlock(&runtime->oss.params_lock); - return xfer; - - err: - mutex_unlock(&runtime->oss.params_lock); return xfer > 0 ? (snd_pcm_sframes_t)xfer : tmp; } |