From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vinod Koul Subject: Re: [PATCH 1/4] ASoC: compress: Pass error out of soc_compr_pointer Date: Fri, 11 Mar 2016 16:44:28 +0530 Message-ID: <20160311111428.GB11154@localhost> References: <1457606694-10985-1-git-send-email-ckeepax@opensource.wolfsonmicro.com> <20160311074843.GV11154@localhost> <20160311100425.GH1490@localhost.localdomain> <20160311103747.GZ11154@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by alsa0.perex.cz (Postfix) with ESMTP id 885A326655C for ; Fri, 11 Mar 2016 12:10:17 +0100 (CET) Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Takashi Iwai Cc: alsa-devel@alsa-project.org, patches@opensource.wolfsonmicro.com, broonie@kernel.org, lgirdwood@gmail.com, Charles Keepax List-Id: alsa-devel@alsa-project.org On Fri, Mar 11, 2016 at 11:39:11AM +0100, Takashi Iwai wrote: > On Fri, 11 Mar 2016 11:37:47 +0100, > Vinod Koul wrote: > > > > On Fri, Mar 11, 2016 at 10:04:25AM +0000, Charles Keepax wrote: > > > On Fri, Mar 11, 2016 at 01:18:43PM +0530, Vinod Koul wrote: > > > > On Thu, Mar 10, 2016 at 10:44:51AM +0000, Charles Keepax wrote: > > > > > The soc_compr_pointer does not correctly pass any errors returned by the > > > > > driver callback back up the stack. This patch corrects this issue. > > > > > > > > Should we do that :) I am not too sure. Pointer query is supposed to read > > > > the current value and return. You are trying to indicate that stream has > > > > gone bad which is not the same as read faced an error... > > > > > > > > Also please use cover letter for these things to describe problem you are > > > > trying to solve. > > > > > > Apologies for not doing so, I had been viewing this as more of a > > > simple oversight in the framework rather than a design choice. > > > > > > The problem I am looking at is the DSP suffers an unrecoverable > > > error. We can find out about this error in our driver because the > > > DSP returns some error status to us. This is fine if user-space > > > is doing a read as reads return error status back to user-space > > > so the user can find out that things have gone bad. However, if > > > user-space is doing an avail request there is no path for the > > > error to come back up to user-space. The pointer request returns > > > zero available data, so a read never happens and we basically > > > just end up sitting waiting for data on a stream that we know > > > full well has died. > > > > So this confirms my hunch and we should then notify core of error by stopping > > the stream properly and then return error on poll/pointer query. > > > > So cna try this untested patch, whcih includes a hack for stopped state. We > > don't seem to have a stopped state in ALSA, that bit would need refinement > > In PCM, the stopped state is either SETUP/PREPARE or XRUN. We didn't use PREPARE so we can set to XRUN. So here is alternate patch for this, whcih looks much better :) -- >8 -- diff --git a/include/sound/compress_driver.h b/include/sound/compress_driver.h index c0abcdc11470..a42c64248ad7 100644 --- a/include/sound/compress_driver.h +++ b/include/sound/compress_driver.h @@ -187,4 +187,5 @@ static inline void snd_compr_drain_notify(struct snd_compr_stream *stream) wake_up(&stream->runtime->sleep); } +int snd_compr_stop(struct snd_compr_stream *stream); #endif diff --git a/sound/core/compress_offload.c b/sound/core/compress_offload.c index 18b8dc45bb8f..5d2a4d30eb6e 100644 --- a/sound/core/compress_offload.c +++ b/sound/core/compress_offload.c @@ -224,6 +224,14 @@ snd_compr_ioctl_avail(struct snd_compr_stream *stream, unsigned long arg) struct snd_compr_avail ioctl_avail; size_t avail; + mutex_lock(&stream->device->lock); + if (stream->runtime->state == SNDRV_PCM_STATE_OPEN || + stream->runtime->state == SNDRV_PCM_STATE_XRUN) { + mutex_unlock(&stream->device->lock); + return -EBADFD; + } + mutex_unlock(&stream->device->lock); + avail = snd_compr_calc_avail(stream, &ioctl_avail); ioctl_avail.avail = avail; @@ -386,7 +394,8 @@ static unsigned int snd_compr_poll(struct file *f, poll_table *wait) return -EFAULT; mutex_lock(&stream->device->lock); - if (stream->runtime->state == SNDRV_PCM_STATE_OPEN) { + if (stream->runtime->state == SNDRV_PCM_STATE_OPEN || + stream->runtime->state == SNDRV_PCM_STATE_XRUN) { retval = -EBADFD; goto out; } @@ -669,7 +678,7 @@ static int snd_compr_start(struct snd_compr_stream *stream) return retval; } -static int snd_compr_stop(struct snd_compr_stream *stream) +static int _snd_compr_stop(struct snd_compr_stream *stream) { int retval; @@ -685,6 +694,20 @@ static int snd_compr_stop(struct snd_compr_stream *stream) return retval; } +int snd_compr_stop(struct snd_compr_stream *stream) +{ + int ret = _snd_compr_stop(stream); + + if (ret) { + mutex_lock(&stream->device->lock); + stream->runtime->state = SNDRV_PCM_STATE_XRUN; + mutex_unlock(&stream->device->lock); + } + + return ret; +} +EXPORT_SYMBOL_GPL(snd_compr_stop); + static int snd_compress_wait_for_drain(struct snd_compr_stream *stream) { int ret; @@ -832,7 +855,7 @@ static long snd_compr_ioctl(struct file *f, unsigned int cmd, unsigned long arg) retval = snd_compr_start(stream); break; case _IOC_NR(SNDRV_COMPRESS_STOP): - retval = snd_compr_stop(stream); + retval = _snd_compr_stop(stream); break; case _IOC_NR(SNDRV_COMPRESS_DRAIN): retval = snd_compr_drain(stream); -- ~Vinod