[alsa-devel] [PATCH 3/3] ALSA: hda - Improved position reporting on SKL+

[Takashi Iwai]

On Mon, 03 Apr 2017 04:58:38 +0200,
Vinod Koul wrote:
> 
> On Fri, Mar 31, 2017 at 10:49:30AM +0200, Takashi Iwai wrote:
> > Apply the same methods to obtain the current stream position as ASoC
> > Intel SKL driver uses.  It reads the position from DPIB for a playback
> > stream while it still reads from the position buffer for a capture
> > stream.  For a capture stream, some ugly workaround is needed to
> > settle down the inconsistent position.
> > 
> > Signed-off-by: Takashi Iwai <tiwai at suse.de>
> > ---
> >  sound/pci/hda/hda_intel.c | 36 ++++++++++++++++++++++++++++++++++--
> >  1 file changed, 34 insertions(+), 2 deletions(-)
> > 
> > diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
> > index a48330f4a1a9..64db6698214c 100644
> > --- a/sound/pci/hda/hda_intel.c
> > +++ b/sound/pci/hda/hda_intel.c
> > @@ -77,6 +77,7 @@ enum {
> >  	POS_FIX_POSBUF,
> >  	POS_FIX_VIACOMBO,
> >  	POS_FIX_COMBO,
> > +	POS_FIX_SKL,
> >  };
> >  
> >  /* Defines for ATI HD Audio support in SB450 south bridge */
> > @@ -148,7 +149,7 @@ module_param_array(model, charp, NULL, 0444);
> >  MODULE_PARM_DESC(model, "Use the given board model.");
> >  module_param_array(position_fix, int, NULL, 0444);
> >  MODULE_PARM_DESC(position_fix, "DMA pointer read method."
> > -		 "(-1 = system default, 0 = auto, 1 = LPIB, 2 = POSBUF, 3 = VIACOMBO, 4 = COMBO).");
> > +		 "(-1 = system default, 0 = auto, 1 = LPIB, 2 = POSBUF, 3 = VIACOMBO, 4 = COMBO, 5 = SKL+).");
> 
> do we have people use this module param, or is it find what works for
> them...

It's for debug purpose, and I know people trying this for various
issues.


Takashi