Re: [PATCH 0/3] ALSA: pcm:

[Takashi Iwai <tiwai@suse.de>]

On Fri, 09 Jun 2017 02:34:37 +0200,
Takashi Sakamoto wrote:
> 
> Hi,
> 
> This patchset is a revised version of my former RFC.
> 
> 
> [alsa-devel] [PATCH RFC 00/21] ALSA: pcm: add tracepoints for PCM params operation
> http://mailman.alsa-project.org/pipermail/alsa-devel/2017-May/120548.html
> 
> In ALSA PCM interface, applications can get hardware capability as
> 'struct snd_pcm_hw_params' type of data returned by a call of ioctl(2)
> with SNDRV_PCM_IOCTL_HW_REFINE/SNDRV_PCM_IOCTL_HW_PARAMS' commands.
> Results of these commands should be the same in a certain conditions but
> actually it's not.
> 
> This is a part of layout of the structure.
> 
> struct snd_pcm_hw_params {
>     ...
>     unsigned int info;
>     unsigned int msbits;
>     unsigned int rate_num;
>     unsigned int rate_den;
>     snd_pcm_uframes_t fifo_size;
>     ...
> };
> 
> For example, although the 'msbits', 'rate_num' and 'rate_den' fields are
> filled in a result of HW_REFINE command conditionally, they're never
> filled in a result of HW_PARAMS command. This seems a bug.
> 
> This patchset attempts to fix the bug. This affects userspace applications
> in cotents of the result, but it's acceptrable with a merit for the
> applications to get enough parameters.
> 
> Takashi Sakamoto (3):
>   ALSA: pcm: use helper functions to refer parameters as constants
>   ALSA: pcm: calculate non-mask/non-interval parameters always when
>     possible
>   ALSA: pcm: move fixup of info flag after selecting single parameters

Applied all three patches now.  Thanks.


Takashi