[PATCH v2] ALSA: pcm: Return 0 when size < start_threshold in capture

[PATCH v2] ALSA: pcm: Return 0 when size < start_threshold in capture

[Ricardo Biehl Pasquali]

In __snd_pcm_lib_xfer(), when capture, if state is PREPARED
and size is less than start_threshold nothing can be done.
As there is no error, 0 is returned.

Signed-off-by: Ricardo Biehl Pasquali <pasqualirb@gmail.com>
---

version 2:
The code was not changed. Just resubmitting to follow the
rules from Documentation/process/submitting-patches.rst.

--- pcm_lib.c.orig	2018-08-21 15:31:54.457405053 -0300
+++ pcm_lib.c	2018-08-21 15:56:01.264549084 -0300
@@ -2125,7 +2125,7 @@ snd_pcm_sframes_t __snd_pcm_lib_xfer(str
 	pcm_transfer_f transfer;
 	bool nonblock;
 	bool is_playback;
-	int err;
+	int err = 0;
 
 	err = pcm_sanity_check(substream);
 	if (err < 0)
@@ -2173,11 +2173,15 @@ snd_pcm_sframes_t __snd_pcm_lib_xfer(str
 		goto _end_unlock;
 
 	if (!is_playback &&
-	    runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
-	    size >= runtime->start_threshold) {
-		err = snd_pcm_start(substream);
-		if (err < 0)
+	    runtime->status->state == SNDRV_PCM_STATE_PREPARED) {
+		if (size >= runtime->start_threshold) {
+			err = snd_pcm_start(substream);
+			if (err < 0)
+				goto _end_unlock;
+		} else {
+			/* nothing to do */
 			goto _end_unlock;
+		}
 	}
 
 	runtime->twake = runtime->control->avail_min ? : 1;

Re: [PATCH v2] ALSA: pcm: Return 0 when size < start_threshold in capture

[Takashi Iwai]

On Wed, 22 Aug 2018 17:03:59 +0200,
Ricardo Biehl Pasquali wrote:
> 
> In __snd_pcm_lib_xfer(), when capture, if state is PREPARED
> and size is less than start_threshold nothing can be done.
> As there is no error, 0 is returned.
> 
> Signed-off-by: Ricardo Biehl Pasquali <pasqualirb@gmail.com>
> ---
> 
> version 2:
> The code was not changed. Just resubmitting to follow the
> rules from Documentation/process/submitting-patches.rst.

Almost good, but still not perfect, unfortunately :)
The patch should be applicable onto the kernel tree as is with -p1
option, i.e. the diff should be like
  --- a/sound/core/pcm_lib.c
  +++ b/sound/core/pcm_lib.c

But never mind, I'll apply this manually at this time, just keep the
above in mind for the next time.

Currently we're dealing with 4.19 merge, hence I'm going to queue to
the branch for 4.20.


thanks,

Takashi


> 
> --- pcm_lib.c.orig	2018-08-21 15:31:54.457405053 -0300
> +++ pcm_lib.c	2018-08-21 15:56:01.264549084 -0300
> @@ -2125,7 +2125,7 @@ snd_pcm_sframes_t __snd_pcm_lib_xfer(str
>  	pcm_transfer_f transfer;
>  	bool nonblock;
>  	bool is_playback;
> -	int err;
> +	int err = 0;
>  
>  	err = pcm_sanity_check(substream);
>  	if (err < 0)
> @@ -2173,11 +2173,15 @@ snd_pcm_sframes_t __snd_pcm_lib_xfer(str
>  		goto _end_unlock;
>  
>  	if (!is_playback &&
> -	    runtime->status->state == SNDRV_PCM_STATE_PREPARED &&
> -	    size >= runtime->start_threshold) {
> -		err = snd_pcm_start(substream);
> -		if (err < 0)
> +	    runtime->status->state == SNDRV_PCM_STATE_PREPARED) {
> +		if (size >= runtime->start_threshold) {
> +			err = snd_pcm_start(substream);
> +			if (err < 0)
> +				goto _end_unlock;
> +		} else {
> +			/* nothing to do */
>  			goto _end_unlock;
> +		}
>  	}
>  
>  	runtime->twake = runtime->control->avail_min ? : 1;
> 

Re: [PATCH v2] ALSA: pcm: Return 0 when size < start_threshold in capture

[Ricardo Biehl Pasquali]

Takashi wrote:
> Almost good, but still not perfect, unfortunately :)
> The patch should be applicable onto the kernel tree as is with -p1
> option, i.e. the diff should be like
>   --- a/sound/core/pcm_lib.c
>   +++ b/sound/core/pcm_lib.c
>
> But never mind, I'll apply this manually at this time, just keep the
> above in mind for the next time.

Ok, thank you!

The .orig thing is ok if I had used the full pathname?

diff does not generate a/ and b/ (at least with '-up'
options). By the way, 'diff -up' is what
submitting-patches document recommends when no git tree
is available.

Re: [PATCH v2] ALSA: pcm: Return 0 when size < start_threshold in capture

[Takashi Iwai]

On Wed, 22 Aug 2018 17:25:24 +0200,
Ricardo Biehl Pasquali wrote:
> 
> Takashi wrote:
> > Almost good, but still not perfect, unfortunately :)
> > The patch should be applicable onto the kernel tree as is with -p1
> > option, i.e. the diff should be like
> >   --- a/sound/core/pcm_lib.c
> >   +++ b/sound/core/pcm_lib.c
> >
> > But never mind, I'll apply this manually at this time, just keep the
> > above in mind for the next time.
> 
> Ok, thank you!
> 
> The .orig thing is ok if I had used the full pathname?

That's OK.  The patch just needs to be simply applicable with -p1.


Takashi