[Intel-gfx] [PATCH 0/4] i915 to call hda driver on HDMI plug/unplug

[Takashi Iwai]

On Tue, 21 Jul 2015 19:37:17 +0200,
R, Durgadoss wrote:
> 
> Hi David,
> 
> >-----Original Message-----
> >From: Intel-gfx [mailto:intel-gfx-bounces at lists.freedesktop.org] On Behalf Of David Henningsson
> >Sent: Tuesday, July 21, 2015 1:27 PM
> >To: alsa-devel at alsa-project.org; intel-gfx at lists.freedesktop.org; tiwai at suse.de; Vetter, Daniel;
> >jani.nikula at linux.intel.com
> >Cc: Koul, Vinod; David Henningsson
> >Subject: [Intel-gfx] [PATCH 0/4] i915 to call hda driver on HDMI plug/unplug
> >
> >This patch set aims to resolve three problems:
> >
> > * The first - and most serious one - is that the audio driver is not woken up
> >   properly when in power save modes, especially not when the HDA controller is
> >   in D3. By having the i915 driver call directly into the hda driver, the HDA
> >   driver is always notified that an HDMI hotplug event has happened.
> >
> > * Second, there is currently no way for userspace to match an HDMI audio output
> >   with an HDMI video output. We fix this by sending connector_type and
> >   connector_type_id in the HDMI hotplug callback.
> >
> > * Third, writing ELD info to the hardware just so the HDA driver can read it
> >   from the hardware seems a bit inefficient. We could just pass that information
> >   in the callback, too.
> >
> >The patch in its current form fixes the first of these problems and provides most
> >of the infrastructure for the second and third problem.
> >
> >The patch set is based on 4.2rc2 + my recent codec wakeup patch. So far, it has
> >been tested (and working) on one Skylake machine.
> 
> I believe you tested these patches with hda driver after few cycles of D3.
> By any chance, did you also try this once after i915 driver's D3 cycle also ?
> In this case, can the check_presence_and_report() function get the
> pin presence and ELD valid bits read out properly..?

The code path will call power well on, thus the i915 driver will be
woken up, in anyway.


thanks,

Takashi