[alsa-devel] Intel SST on a Bay Trail tablet

[Vinod Koul]

On Fri, Jun 26, 2015 at 03:05:28PM +0200, Antonio Ospite wrote:
> On Thu, 25 Jun 2015 22:17:17 +0530
> Vinod Koul <vinod.koul at intel.com> wrote:
> 
> > On Thu, Jun 25, 2015 at 12:21:24PM +0200, Antonio Ospite wrote:
> > > On Thu, 25 Jun 2015 11:20:46 +0530
> > > Vinod Koul <vinod.koul at intel.com> wrote:
> > > 
> > > > On Wed, Jun 24, 2015 at 03:46:13PM +0530, Vinod Koul wrote:
> > > > > On Tue, Apr 14, 2015 at 05:06:27PM +0300, Jarkko Nikula wrote:
> > > [...]
> > > > > > 
> > > > > > Which makes me thinking how does those strings describe the SSP port
> > > > > > setup? E.g. do they reflect what port is actually used or could it
> > > > > > be possible that those are just driver strings but firmware could
> > > > > > have been tuned for SSP0? If I looked at earlier right, Teclast has
> > > > > > the low pin-count Baytrail without SSP2 but I'm not sure about that.
> > > > > The FW doesnt provide way to changes ports from driver in this, so this
> > > > > doesnt mean much. If we are sure it is not ssp2, I can provide ssp1 fw for
> > > > > test
> > > > I ahve pushed latest BYT version we have as well as added binary for second
> > > > SSP port. Please give it a try:
> > > > 
> > > > https://git.kernel.org/cgit/linux/kernel/git/vkoul/firmware.git/commit/?h=byt&id=28ff420dd33ec299217bad7d526ff3bfd163b551
> > > > 
> > > 
> > > Thanks Vinod, but I see these are in the ELF format, and the mainline
> > > driver does not support this format, at least the last time I checked it
> > > didn't.
> > My bad, updated the patch now with right format
> > 
> > https://git.kernel.org/cgit/linux/kernel/git/vkoul/firmware.git/commit/?h=byt
> >
> 
> (Adding Michele to CC)
> 
> OK, so Jarkko was right: after a quick test I confirm that with
> fw_sst_0f28_ssp0.bin I get sound; this is quite an improvement,
> thanks!
Okay that is great

> 
> I am going to update the report on bugzilla:
> https://bugzilla.kernel.org/show_bug.cgi?id=86581
> 
> I used the amixer commands which Vinod provided in the other thread,
> in particular, the playback path is this one:
> 
> > amixer -c0 sset 'codec_out0 mix 0 pcm0_in' on
> > amixer -c0 sset 'media0_out mix 0 media1_in' on
> 
> The sound is a bit distorted tho, I can alleviate this effect by
> lowering the values of these controls:
>   - codec_out0 Gain0
>   - media1_in Gain0
>   - pcm0_in Gain0
> 
> but the distortions do not go completely away, and they are not present
> in Android even at the highest volume.
I dont think the gain is causing the distortion. It can be SSP settings
DO you see distortion in one channel or both (try with headset)

Also on Android, do you know kernel source for this, if vendor did release
we cna check the settings there and configure the same here. Also cna you
confirm which machine driver was loaded

> 
> I will perform more tests (capture, headphones) when 4.2-rc1 is out
> and report back the results.
> 
> JFTR, I made sure to use the DPCM driver by preventing the other one
> from being loaded:
You should blacklist that one ...

-- 
~Vinod

> 
> diff --git a/sound/soc/intel/common/sst-acpi.c b/sound/soc/intel/common/sst-acpi.c
> index 42f293f..66ee705 100644
> --- a/sound/soc/intel/common/sst-acpi.c
> +++ b/sound/soc/intel/common/sst-acpi.c
> @@ -266,7 +266,6 @@ static struct sst_acpi_desc sst_acpi_baytrail_desc = {
>  static struct acpi_device_id sst_acpi_match[] = {
>         { "INT33C8", (unsigned long)&sst_acpi_haswell_desc },
>         { "INT3438", (unsigned long)&sst_acpi_broadwell_desc },
> -       { "80860F28", (unsigned long)&sst_acpi_baytrail_desc },
>         { }
>  };
>  MODULE_DEVICE_TABLE(acpi, sst_acpi_match);
> 
> Would it be worth providing a SSP0 variant of
> fw_sst_0f28.bin-48kHz_i2s_master too? Or is the intel/atom/sst/sst_acpi.c
> going to completely replace intel/common/sst-acpi.c?
> 
> Thanks a lot,
>    Antonio
> 
> -- 
> Antonio Ospite
> http://ao2.it
> 
> A: Because it messes up the order in which people normally read text.
>    See http://en.wikipedia.org/wiki/Posting_style
> Q: Why is top-posting such a bad thing?

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