[Letux-kernel] AESS / Audio Driver for Pyra

Andreas Kemnade andreas at kemnade.info
Tue Oct 30 07:01:52 CET 2018


On Mon, 29 Oct 2018 15:42:49 +0100
"H. Nikolaus Schaller" <hns at goldelico.com> wrote:

> Hi all,
> 
> > Am 29.10.2018 um 13:50 schrieb H. Nikolaus Schaller <hns at goldelico.com>:
> > 
> >   
> >> Am 29.10.2018 um 12:44 schrieb Michael Mrozek <EvilDragon at openpandora.org>:
> >> 
> >> Hi,
> >> 
> >> AESS / Audio is one of the biggest remaining issues we have on the Pyra.
> >> Everything else seems to work good enough for a start now, but missing audio on
> >> a gaming handheld is a bit annoying :)
> >> 
> >> With some kernel version, speaker output stopped completely, but Nikolaus is
> >> currently looking into what changed with each kernel version and when exactly it
> >> stopped working to get this to work again, at least.  
> > 
> > Ok, here is the result:
> > 
> > letux-4.16-rc3	is the last version where audio works fine
> > letux-4.16-rc4	makes the play command stop after some random time (ca. 1 .. 8 seconds)
> > 		and audio sounds fluttering like a damaged capstan
> > 
> > In letux-4.17 and later there is no sound from the handsfree speakers any more,
> > but headsets work. At least sometimes.  
> 
> I have tried to find diffs for twl6040 or generally sound/ or mcpdm driver or
> device tree changes. But there aren't any.
> 
> What I did ffind is a diff in the letux_defconfig:
> 
> > -# CONFIG_CPU_IDLE is not set
> > +CONFIG_CPU_IDLE=y
> > +CONFIG_CPU_IDLE_MULTIPLE_DRIVERS=y
> > +# CONFIG_CPU_IDLE_GOV_LADDER is not set
> > +CONFIG_CPU_IDLE_GOV_MENU=y
> > +CONFIG_DT_IDLE_STATES=y
> > +
> > +#
> > +# ARM CPU Idle Drivers
> > +#
> > +CONFIG_ARM_CPUIDLE=y
> > 
> > +CONFIG_VIDEOBUF2_V4L2=m  
> 
> Could CPU_IDLE break the twl6040 audio subsystem? No idea. Therefore, I tried to remove it from 4.19.
> 
> And ... it makes audio work!
> 
> So we have a simple fix for 4.19. Although no explanation. And no idea how to make it work with CONFIG_CPU_IDLE=y.
> 
What about simply adding pm_qos stuff like in omap-mcbsp.c to
omap-abe-twl6030.c? If used harsh enough it should prevent any
cpu idling. This as a first step.
As a second step, RTFM again and check what can be idled and what not.

Well, no hardware here to test it myself.

Regards,
Andreas
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 833 bytes
Desc: OpenPGP digital signature
URL: <http://lists.goldelico.com/pipermail/letux-kernel/attachments/20181030/0904129a/attachment.asc>


More information about the Letux-kernel mailing list