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

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Message-ID: <20160209170351.GT23290@intel.com>
Date:	Tue, 9 Feb 2016 19:03:51 +0200
From:	Ville Syrjälä <ville.syrjala@...ux.intel.com>
To:	"Sharma, Shashank" <shashank.sharma@...el.com>
Cc:	Nick Bowler <nbowler@...conx.ca>,
	"Jindal, Sonika" <sonika.jindal@...el.com>,
	Daniel Vetter <daniel.vetter@...ll.ch>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>
Subject: Re: PROBLEM: Intel HDMI output busticated on 4.4 (regression)

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)
-- 
2.4.10


> 
> Regards
> Shashank
> -----Original Message-----
> From: Nick Bowler [mailto:nbowler@...conx.ca] 
> Sent: Tuesday, February 09, 2016 10:03 PM
> To: Jindal, Sonika
> Cc: linux-kernel@...r.kernel.org; dri-devel@...ts.freedesktop.org; Daniel Vetter; Sharma, Shashank
> Subject: Re: PROBLEM: Intel HDMI output busticated on 4.4 (regression)
> 
> On 1/28/16, Nick Bowler <nbowler@...conx.ca> wrote:
> > On 2016-01-21, Nick Bowler <nbowler@...conx.ca> wrote:
> >> On 2016-01-21, Jindal, Sonika <sonika.jindal@...el.com> wrote:
> >>> On 1/21/2016 8:59 AM, Nick Bowler wrote:
> >>>> On 1/20/16, Nick Bowler <nbowler@...conx.ca> wrote:
> >>>>> On 2016-01-20, Jindal, Sonika <sonika.jindal@...el.com> 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@...ts.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Ville Syrjälä
Intel OTC


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