[alsa-devel] [PATCH 0/3] Add SPIB Support for Intel Skylake platforms

Vinod Koul vinod.koul at intel.com
Tue Jan 30 12:44:32 CET 2018


On Tue, Jan 30, 2018 at 04:37:44PM +0530, Subhransu S. Prusty wrote:
> On Tue, Jan 30, 2018 at 04:08:39PM +0530, Takashi Sakamoto wrote:
> > Hi,

Hi Takashi Sakamoto,

> > In my opinion, when drivers
> > return appropriate values at implementations of
> > "struct snd_pcm_ops.pointer" and "struct snd_pcm_ops.ack", your aim is
> > satisfied. In short, you can let ALSA PCM core to handle
> > rewinding/forwarding requests from userland for zero number of handled
> > frames in result. So the 'SNDRV_PCM_HW_PARAMS_NO_REWINDS' flag is
> > useless.
> 
> Based on the earlier discussion in v3, this series includes the usage of the
> 'SNDRV_PCM_HW_PARAMS_NO_REWINDS' flag. Please refer to the discussion on
> https://patchwork.kernel.org/patch/9795233/

Also it is worth mentioning that this supports a HW feature which requires
the knowledge of data available in ring buffer to be provided to hardware.
With the feature enabled, we cannot rewind/forward, hence the support is
dependent upon application querying about no rewind capability and setting
it, otherwise this feature is not enabled...

> 
> > 
> > From me, please refer to our previous discussion about this
> > flag[1][2][3], then describe your insistence of this flag. At least,
> > it's not better idea to abandon the old discussion when posting this
> > kind of patches. Additionally you should add 'v4' in title of this
> 
> Yes should have added the reference and v4. Sorry to have missed it.

-- 
~Vinod


More information about the Alsa-devel mailing list