[Intel-gfx] [PATCH v3 09/10] drm/i915: Keep PSR disabled after a driver reload after a PSR error

[Souza, Jose]

On Wed, 2018-10-31 at 16:45 -0700, Dhinakaran Pandiyan wrote:
> On Thu, 2018-10-25 at 18:17 -0700, José Roberto de Souza wrote:
> > If a PSR error happened and the driver is reloaded, the EDP_PSR_IIR
> > will still keep the error set even after the reset done in the
> > irq_preinstall and irq_uninstall hooks.
> 
> Does this happen or are you suspecting it might? Is this because IIR
> clearing did not work or is it because of a new unhandled interrupt?

It happens, it is cleared I can read it back right after clear it and
the value is correct but it is still set. I did some tests like clear
IIR with the interruption unmasked but it also don't work.

> 
> -DK
> 
> 
> 
> > And enabling in this situation cause the screen to freeze in the
> > first time that PSR HW tries to activate so lets keep PSR disabled
> > to avoid any rendering problems.
> > 
> > Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> > Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_psr.c | 13 +++++++++++++
> >  1 file changed, 13 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_psr.c
> > b/drivers/gpu/drm/i915/intel_psr.c
> > index 68201cc24d25..718270da1061 100644
> > --- a/drivers/gpu/drm/i915/intel_psr.c
> > +++ b/drivers/gpu/drm/i915/intel_psr.c
> > @@ -529,6 +529,19 @@ void intel_psr_compute_config(struct intel_dp
> > *intel_dp,
> >  		return;
> >  	}
> >  
> > +	/*
> > +	 * If a PSR error happened and the driver is reloaded, the
> > EDP_PSR_IIR
> > +	 * will still keep the error set even after the reset done in
> > the
> > +	 * irq_preinstall and irq_uninstall hooks.
> > +	 * And enabling in this situation cause the screen to freeze in
> > the
> > +	 * first time that PSR HW tries to activate so lets keep PSR
> > disabled
> > +	 * to avoid any rendering problems.
> > +	 */
> > +	if (I915_READ(EDP_PSR_IIR) & EDP_PSR_ERROR(TRANSCODER_EDP)) {
> > +		DRM_DEBUG_KMS("PSR interruption error set\n");
> > +		return;
> > +	}
> > +
> >  	if (IS_HASWELL(dev_priv) &&
> >  	    I915_READ(HSW_STEREO_3D_CTL(crtc_state->cpu_transcoder)) &
> >  		      S3D_ENABLE) {