[Intel-gfx] [PATCH v2 22/22] drm/i915/audio: Resume HSW/BDW HDA controller around ELD access

[Kai Vehmanen]

Hi,

On Wed, 12 Oct 2022, Kai Vehmanen wrote:

> On Wed, 12 Oct 2022, Ville Syrjala wrote:
> 
> > On HSW/BDW the hardware ELD buffer does not work if the controller
> > is suspended. I'm not 100% which thing in there is needed to make it
> > work (at least just forcing the controller into D0 with setpci is
> 
> how does the error show up? I'm puzzled how this could have gone 
> unreported for so long. I know many distros have had runtime PM disabled 
> for the HDA controller driver, so that could perhaps explain some of this, 
> but still seems a bit amazing.
> 
> We started SOF testing with upstream around GLK, so we never covered 
> HSW/BDW, but surely in SOF we always have runtime suspend by default 
> enabled on the audio side.
> 
> I'll need some more time for review. Will follow up later.

adding Cezary to the mail thread as well (I forwarded you some context
separately.

Br, Kai