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

[Wu Fengguang]

> > > 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.
> 
> It depends on timing. When audio driver receives the unsolicited event, 
> graphics driver has finished with "eld_valid = 1", hence
> AC_VERB_GET_PIN_SENSE returns ELDV=1.
> 
> It's not happening /all the time/ though. For example here is another
> dmesg showing a different timing on the same test box.

Sorry this is actually from another test box. But I did see similar
ones from the same test box.

> [  467.561516] [drm:intel_dp_mode_set], Enabling DP audio on pipe B
> [  467.567503] [drm:intel_write_eld], ELD on [CONNECTOR:26:DP-3], [ENCODER:27:TMDS-27]
> [  467.574207] [drm:ironlake_write_eld], ELD on pipe B
> [  467.579346] [drm:ironlake_write_eld], Audio directed to unknown port
> [  467.584724] [drm:ironlake_write_eld], ELD: DisplayPort detected
> [  467.586540] HDMI hot plug event: Codec=3 Pin=7 Presence_Detect=1 ELD_Valid=0
> [  467.599608] [drm:ironlake_write_eld],                    
> [  467.599922] HDMI status: Codec=3 Pin=7 Presence_Detect=1 ELD_Valid=0
> [  467.605834] ELD size 9                                           
> [  467.610434] [drm:sandybridge_update_wm], FIFO watermarks For pipe A - plane 7, cursor: 6
> [  467.612365] HDMI hot plug event: Codec=3 Pin=7 Presence_Detect=1 ELD_Valid=1
> [  467.620654] [drm:sandybridge_update_wm],                 
> [  467.620765] HDMI status: Codec=3 Pin=7 Presence_Detect=1 ELD_Valid=1