Re: PROBLEM: Intel HDMI output busticated on 4.4 (regression)

From: Ville Syrjälä
Date: Tue Feb 09 2016 - 12:36:50 EST


On Tue, Feb 09, 2016 at 07:03:51PM +0200, Ville Syrjälä wrote:
> On Tue, Feb 09, 2016 at 04:39:21PM +0000, Sharma, Shashank wrote:
> > Hi Nick,
> >
> > Sonika is OOO for this week.
> > AFAIK about this issue, looks like the live status is not getting set for your system, on HPD.
> >
> > As per the Bspec, we must check live status before trying to read EDID.
> > Is it possible for you to check with an HDMI analyzer and probe live status register ?
>
> BTW I'm not at all convinced about the current live status bit defines
> we have for g4x. Supposedly someone tested them and found that they
> don't match the spec, but IIRC when I tried them on one g4x machine
> here, they did match the spec (well, at least for the ports present
> on that particular board).
>
> So something like this may or may not help:
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 188ad5de020f..80c08016e522 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -3302,9 +3302,9 @@ enum skl_disp_power_wells {
> * Please check the detailed lore in the commit message for for experimental
> * evidence.
> */
> -#define PORTD_HOTPLUG_LIVE_STATUS_G4X (1 << 29)
> +#define PORTD_HOTPLUG_LIVE_STATUS_G4X (1 << 27)
> #define PORTC_HOTPLUG_LIVE_STATUS_G4X (1 << 28)
> -#define PORTB_HOTPLUG_LIVE_STATUS_G4X (1 << 27)
> +#define PORTB_HOTPLUG_LIVE_STATUS_G4X (1 << 29)
> /* VLV DP/HDMI bits again match Bspec */
> #define PORTD_HOTPLUG_LIVE_STATUS_VLV (1 << 27)
> #define PORTC_HOTPLUG_LIVE_STATUS_VLV (1 << 28)

Just retested the g4x machine here, and port B is definitely on bit 29,
port C on bit 28. No port D on ELK, so can't check that. So either
someone made a fumble when they tested this originally, or some boards
are just wired incorrectly, or CTG is where it was tested and that
actually disagrees with the spec for some reason.

> --
> 2.4.10
>
>
> >
> > Regards
> > Shashank
> > -----Original Message-----
> > From: Nick Bowler [mailto:nbowler@xxxxxxxxxx]
> > Sent: Tuesday, February 09, 2016 10:03 PM
> > To: Jindal, Sonika
> > Cc: linux-kernel@xxxxxxxxxxxxxxx; dri-devel@xxxxxxxxxxxxxxxxxxxxx; Daniel Vetter; Sharma, Shashank
> > Subject: Re: PROBLEM: Intel HDMI output busticated on 4.4 (regression)
> >
> > On 1/28/16, Nick Bowler <nbowler@xxxxxxxxxx> wrote:
> > > On 2016-01-21, Nick Bowler <nbowler@xxxxxxxxxx> wrote:
> > >> On 2016-01-21, Jindal, Sonika <sonika.jindal@xxxxxxxxx> wrote:
> > >>> On 1/21/2016 8:59 AM, Nick Bowler wrote:
> > >>>> On 1/20/16, Nick Bowler <nbowler@xxxxxxxxxx> wrote:
> > >>>>> On 2016-01-20, Jindal, Sonika <sonika.jindal@xxxxxxxxx> wrote:
> > >> [...]
> > >>>>>> Does the same system works with any other monitor?
> > >>>>> I'll see if I can find another to try.
> > >>>> I tried another monitor, and the same problem occurs.
> > >>> Which make are these monitors?
> > >>
> > >> - LG Flatron W2253V
> > >> - Dell E228WFPc
> > >>
> > >>> Do you have any other system other than G45?
> > >>
> > >> Nothing else with Linux 4.4, unfortunately.
> > >
> > > Anything else you want me to try?
> > >
> > > This issue is still present in 4.5-rc1.
> >
> > Ping?
> >
> > HDMI is still broken on my system in 4.5-rc3.
> >
> > Cheers,
> > Nick
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel@xxxxxxxxxxxxxxxxxxxxx
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
>
> --
> Ville Syrjälä
> Intel OTC
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> dri-devel@xxxxxxxxxxxxxxxxxxxxx
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--
Ville Syrjälä
Intel OTC