On 10/29/2015 12:25 PM, ville.syrj...@linux.intel.com wrote: > From: Ville Syrjälä <ville.syrj...@linux.intel.com> > > We get spurious PCH FIFO underruns if we enable the reporting too soon > after enabling the crtc. Move it to be the last step, after the encoder > enable. Additionally we need an extra vblank wait, otherwise we still > get the underruns. Presumably the pipe/fdi isn't yet fully up and running > otherwise. > > For symmetry, disable the PCH underrun reporting as the first thing, > just before encoder disable, when shutting down the crtc. > > Signed-off-by: Ville Syrjälä <ville.syrj...@linux.intel.com> > --- > drivers/gpu/drm/i915/intel_display.c | 13 +++++++++---- > 1 file changed, 9 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_display.c > b/drivers/gpu/drm/i915/intel_display.c > index 99fb33f..d5cb899 100644 > --- a/drivers/gpu/drm/i915/intel_display.c > +++ b/drivers/gpu/drm/i915/intel_display.c > @@ -4874,7 +4874,6 @@ static void ironlake_crtc_enable(struct drm_crtc *crtc) > intel_crtc->active = true; > > intel_set_cpu_fifo_underrun_reporting(dev_priv, pipe, true); > - intel_set_pch_fifo_underrun_reporting(dev_priv, pipe, true); > > for_each_encoder_on_crtc(dev, crtc, encoder) > if (encoder->pre_enable) > @@ -4912,6 +4911,12 @@ static void ironlake_crtc_enable(struct drm_crtc *crtc) > > if (HAS_PCH_CPT(dev)) > cpt_verify_modeset(dev, intel_crtc->pipe); > + > + if (intel_crtc->config->has_pch_encoder) { > + /* Must wait for vblank to avoid spurious PCH FIFO underruns */ > + intel_wait_for_vblank(dev, pipe); > + intel_set_pch_fifo_underrun_reporting(dev_priv, pipe, true); > + } > } > > /* IPS only exists on ULT machines and is tied to pipe A. */ > @@ -5040,15 +5045,15 @@ static void ironlake_crtc_disable(struct drm_crtc > *crtc) > int pipe = intel_crtc->pipe; > u32 reg, temp; > > + if (intel_crtc->config->has_pch_encoder) > + intel_set_pch_fifo_underrun_reporting(dev_priv, pipe, false); > + > for_each_encoder_on_crtc(dev, crtc, encoder) > encoder->disable(encoder); > > drm_crtc_vblank_off(crtc); > assert_vblank_disabled(crtc); > > - if (intel_crtc->config->has_pch_encoder) > - intel_set_pch_fifo_underrun_reporting(dev_priv, pipe, false); > - > intel_disable_pipe(intel_crtc); > > ironlake_pfit_disable(intel_crtc, false); >
Reviewed-by: Jesse Barnes <jbar...@virtuousgeek.org> _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx