[alsa-devel] [PATCH 2/2] hda - delayed ELD repoll

[Takashi Iwai]

At Wed, 16 Nov 2011 07:51:28 -0800,
Stephen Warren wrote:
> 
> > > 250mS almost sounds like it's setting ELDV in the audio HW,
> > > then going and reading the EDID, then writing the EDID to the audio HW;
> > > perhaps the graphics driver is accidentally setting PRESENT+ELDV when it's
> > > meant to be setting just PRESENT, and later setting ELDV?
> > 
> > From the debug dmesg, I'm pretty sure that the ELDV events are
> > triggered exactly by the "eld_valid = 0" and "eld_valid = 1" register
> > writes. Since the ELD data is already prepared, there is no EDID read
> > in between.
> > 
> > Below is the dmesg representing a video mode set.
> > 
> > ELD writes from the graphics driver
> > 
> > [  424.254958] [drm:intel_write_eld], ELD on [CONNECTOR:12:HDMI-A-2], [ENCODER:11:TMDS-11]
> > [  424.257670] [drm:ironlake_write_eld], ELD on pipe B
> > [  424.259833] [drm:ironlake_write_eld], Audio directed to unknown port
> > [  424.262156] [drm:ironlake_write_eld], ELD size 13
> > 
> > ELD events received by audio driver (eld reads 0)
> > 
> > [  424.263258] HDMI hot plug event: Codec=3 Pin=6 Presence_Detect=1 ELD_Valid=0
> 
> That line makes sense.
> 
> > [  424.265877] HDMI status: Codec=3 Pin=6 Presence_Detect=1 ELD_Valid=1
> 
> I don't /think/ it's related to this issue, but I wonder why ELDV==1 in
> that message; it seems that the unsolicited response contains the correct
> data, but AC_VERB_GET_PIN_SENSE contains ELDV==1 all the time. That's odd.

Note that this bit isn't from GET_PIN_SENSE verb but the bit in the
unsol event argument.


Takashi