On Mon, 08 Sep 2014, ville.syrjala@xxxxxxxxxxxxxxx wrote: > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > The vblank waits in intel_tv_detect_type() are timing out for some > reason. This is a regression caused removing seemingly useless vblank > waits from the modeset seqeuence in: > > commit 56ef52cad5e37fca89638e4bad598a994ecc3d9f > Author: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > Date: Thu May 8 19:23:15 2014 +0300 > > drm/i915: Kill vblank waits after pipe enable on gmch platforms > > So it turns out they weren't all entirely useless. Apparently the pipe > has to go through one full frame before we enable the TV port. Add a > vblank wait to intel_enable_tv() to make sure that happens. > > Another approach was attempted by placing the vblank wait just after > enabling the port. The theory behind that attempt was that we need to > let the port stay enabled for one full frame before disabling it again > during load detection. But that didn't work, and we definitely must > have the vblank wait before enabling the port. > > Cc: stable@xxxxxxxxxxxxxxx > Cc: Alan Bartlett <ajb@xxxxxxxxxx> > Tested-by: Alan Bartlett <ajb@xxxxxxxxxx> > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=79311 > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Pushed to drm-intel-fixes with Daniel's IRC r-b. Thanks for the patch and review. BR, Jani. > --- > drivers/gpu/drm/i915/intel_tv.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/gpu/drm/i915/intel_tv.c b/drivers/gpu/drm/i915/intel_tv.c > index c69d3ce..c14341c 100644 > --- a/drivers/gpu/drm/i915/intel_tv.c > +++ b/drivers/gpu/drm/i915/intel_tv.c > @@ -854,6 +854,10 @@ intel_enable_tv(struct intel_encoder *encoder) > struct drm_device *dev = encoder->base.dev; > struct drm_i915_private *dev_priv = dev->dev_private; > > + /* Prevents vblank waits from timing out in intel_tv_detect_type() */ > + intel_wait_for_vblank(encoder->base.dev, > + to_intel_crtc(encoder->base.crtc)->pipe); > + > I915_WRITE(TV_CTL, I915_READ(TV_CTL) | TV_ENC_ENABLE); > } > > -- > 1.8.5.5 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
