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<b><a class="bz_bug_link
bz_status_NEW "
title="NEW - [BDW][drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!"
href="https://bugs.freedesktop.org/show_bug.cgi?id=92084#c16">Comment # 16</a>
on <a class="bz_bug_link
bz_status_NEW "
title="NEW - [BDW][drm:gen8_irq_handler [i915]] *ERROR* The master control interrupt lied (SDE)!"
href="https://bugs.freedesktop.org/show_bug.cgi?id=92084">bug 92084</a>
from <span class="vcard"><a class="email" href="mailto:ville.syrjala@linux.intel.com" title="Ville Syrjala <ville.syrjala@linux.intel.com>"> <span class="fn">Ville Syrjala</span></a>
</span></b>
<pre>(In reply to Jani Nikula from <a href="show_bug.cgi?id=92084#c15">comment #15</a>)
<span class="quote">> (In reply to Ville Syrjala from <a href="show_bug.cgi?id=92084#c13">comment #13</a>)
> > (In reply to Jani Nikula from <a href="show_bug.cgi?id=92084#c12">comment #12</a>)
> > > However this helps. We're missing something.
> > >
> > > diff --git a/drivers/gpu/drm/i915/i915_irq.c
> > > b/drivers/gpu/drm/i915/i915_irq.c
> > > index 76bd40e13391..0d524034abd7 100644
> > > --- a/drivers/gpu/drm/i915/i915_irq.c
> > > +++ b/drivers/gpu/drm/i915/i915_irq.c
> > > @@ -1827,6 +1827,9 @@ static void ibx_hpd_irq_handler(struct drm_device
> > > *dev, u32 hotplug_trigger,
> > > dig_hotplug_reg = I915_READ(PCH_PORT_HOTPLUG);
> > > I915_WRITE(PCH_PORT_HOTPLUG, dig_hotplug_reg);
> >
> > Is the read alone enough, or do you need the write too?
>
> Moving the write below the !hotplug_trigger check brings the problem back,
> i.e. the write is also needed.</span >
Are the status bits actually showing long/short pulses when this happens?
Maybe we can just do something like this:
dig_hotplug_reg = I915_READ(PCH_PORT_HOTPLUG);
if (!hotplug_trigger)
dig_hotplug_reg &= ~(*_HOTPLUG_STATUS_MASK);
I915_WRITE(PCH_PORT_HOTPLUG, dig_hotplug_reg
if (!hotplug_trigger)
return;</pre>
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