| Message ID | 541F3A31.3080604@ladisch.de (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Takashi Iwai |
| Headers | show |
At Sun, 21 Sep 2014 22:50:57 +0200, Clemens Ladisch wrote: > > The calculated frame size was wrong because snd_pcm_format_physical_width() > actually returns the number of bits, not bytes. > > Use snd_pcm_format_size() instead, which not only returns bytes, but also > simplifies the calculation. > > Fixes: 8bea869c5e56 ("ALSA: PCM midlevel: improve fifo_size handling") > Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Thanks, applied now. I put Cc to stable as this is a clear bug fix. Takashi > --- > sound/core/pcm_lib.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c > index b03c7ae..dfc2854 100644 > --- a/sound/core/pcm_lib.c > +++ b/sound/core/pcm_lib.c > @@ -1784,14 +1784,16 @@ static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream, > { > struct snd_pcm_hw_params *params = arg; > snd_pcm_format_t format; > - int channels, width; > + int channels; > + ssize_t frame_size; > > params->fifo_size = substream->runtime->hw.fifo_size; > if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) { > format = params_format(params); > channels = params_channels(params); > - width = snd_pcm_format_physical_width(format); > - params->fifo_size /= width * channels; > + frame_size = snd_pcm_format_size(format, channels); > + if (frame_size > 0) > + params->fifo_size /= (unsigned)frame_size; > } > return 0; > } >
diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index b03c7ae..dfc2854 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -1784,14 +1784,16 @@ static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream, { struct snd_pcm_hw_params *params = arg; snd_pcm_format_t format; - int channels, width; + int channels; + ssize_t frame_size; params->fifo_size = substream->runtime->hw.fifo_size; if (!(substream->runtime->hw.info & SNDRV_PCM_INFO_FIFO_IN_FRAMES)) { format = params_format(params); channels = params_channels(params); - width = snd_pcm_format_physical_width(format); - params->fifo_size /= width * channels; + frame_size = snd_pcm_format_size(format, channels); + if (frame_size > 0) + params->fifo_size /= (unsigned)frame_size; } return 0; }
The calculated frame size was wrong because snd_pcm_format_physical_width() actually returns the number of bits, not bytes. Use snd_pcm_format_size() instead, which not only returns bytes, but also simplifies the calculation. Fixes: 8bea869c5e56 ("ALSA: PCM midlevel: improve fifo_size handling") Signed-off-by: Clemens Ladisch <clemens@ladisch.de> --- sound/core/pcm_lib.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)