[Intel-gfx] [PATCH 1/2] drm/i915: fix the SDE irq dmesg warnings properly

[Ville Syrjälä]

On Sun, Dec 13, 2015 at 12:49:45PM +0000, Chris Wilson wrote:
> On Wed, Nov 25, 2015 at 04:47:22PM +0200, Jani Nikula wrote:
> > We had the "The master control interrupt lied (SDE)!" check and error
> > message in place for a long time without any problems, until
> > 
> > commit aaf5ec2e51ab1d9c5e962b4728a1107ed3ff7a3e
> > Author: Sonika Jindal <sonika.jindal at intel.com>
> > Date:   Wed Jul 8 17:07:47 2015 +0530
> > 
> >     drm/i915: Handle HPD when it has actually occurred
> > 
> > caused the errors to start happening. This was bisected and reported,
> > but the error message was silenced in
> > 
> > commit 97e5ed1111dcc5300a0f59a55248cd243937a8ab
> > Author: Daniel Vetter <daniel.vetter at ffwll.ch>
> > Date:   Fri Oct 23 10:56:12 2015 +0200
> > 
> >     drm/i915: shut up gen8+ SDE irq dmesg noise
> > 
> > shooting the messenger while the debugging for why Sonika's commit
> > triggered the errors was still in progress.
> > 
> > It looks like we need to read and acknowledge the PCH_PORT_HOTPLUG
> > register even though the hotplug trigger indicates there isn't a hotplug
> > irq to handle.
> > 
> > Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > Cc: Sonika Jindal <sonika.jindal at intel.com>
> > Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92084
> > Fixes: aaf5ec2e51ab ("drm/i915: Handle HPD when it has actually occurred")
> > Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> 
> And to you I say:
> 
> [    4.249930] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.251037] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.251403] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.252141] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.252509] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.253247] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.253616] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.253985] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.254724] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.255460] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.256198] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.256567] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.257305] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.258043] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.258781] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.259519] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.259889] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.260626] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.261365] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.261734] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.262103] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.262163] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.263261] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.263999] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.264737] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.265106] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> [    4.266214] [drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!
> 
> i7-5557U nuc currently connected to HDMI.

Sigh. Do those correcpond to AUX attempts by any chance? IIRC that was where
Jani saw the problem on his BDW.

Oh and maybe you can try Jani's debug patch
https://bugs.freedesktop.org/show_bug.cgi?id=92084#c20
to show us what the hotplug register says during these fails?

-- 
Ville Syrjälä
Intel OTC