[alsa-devel] [PATCH v2] ALSA: hda - program ICT bits to support HBR audio

[Takashi Iwai]

On Mon, 25 Sep 2017 16:56:53 +0200,
Subhransu S. Prusty wrote:
> 
> On Wed, Sep 20, 2017 at 08:12:36AM -0500, Pierre-Louis Bossart wrote:
> > On 9/20/17 5:00 AM, Takashi Iwai wrote:
> > >On Wed, 20 Sep 2017 00:25:05 +0200,
> > >Pierre-Louis Bossart wrote:
> > >>
> > >>From: Sriram Periyasamy <sriramx.periyasamy at intel.com>
> > >>
> > >>On recent Intel platforms (Haswell, Broadwell, Skylake, ApolloLake,
> > >>KabyLake, ...), the IEC Coding Type (ICT) bitfield in the Digital
> > >>Converter Control #3 needs to be set explicitly for HDMI/DisplayPort
> > >>High Bit Rate (HBR) audio playback to work. This was not required in
> > >>earlier platforms when HBR was first introduced. The ICT bits are
> > >>defined in Section 7.3.3.9 of the HDaudio 1.0a specification.
> > >>
> > >>Since the ICT bitfield was not specified for HDAudio 1.0 devices
> > >>(before 2009), we only program it on machines more recent than
> > >>Haswell.
> > >>
> > >>We tested that this fix is not needed on Baytrail-I (MinnowBoard
> > >>Turbot) and believe by extension it also does not apply to Braswell.
> > >>
> > >>Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98797
> > >>
> > >>Signed-off-by: Sriram Periyasamy <sriramx.periyasamy at intel.com>
> > >>Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
> > >>Signed-off-by: Subhransu S. Prusty <subhransu.s.prusty at intel.com>
> > >>---
> > >>v2: move digi3 verb in Set section, only set ICT for haswell and newer
> > >
> > >Applied now with a slight fix (moving *_SET_* definition to the right
> > >place).
> > 
> > Thanks Takashi. Not sure what happened since I have a clear memory
> > of doing that change and making a note of it...
> 
> Hi Takashi,
> 
> I think this patch should have also gone to stable. We didn't cc. Please
> suggest whether we should submit it separately for stable.

In such a case, please send a mail to Greg KH once after the patch
gets merged to Linus tree and tell him the upstream git commit id to
cherry-pick for stable kernels.


thanks,

Takashi