On Thu, Aug 04, 2016 at 08:03:09AM +0100, Chris Wilson wrote: > On Thu, Aug 04, 2016 at 09:57:11AM +0300, Ville Syrjälä wrote: > > On Wed, Aug 03, 2016 at 05:16:42PM +0100, Chris Wilson wrote: > > > Erratum SKL075: Display Flicker May Occur When Both VT-d And FBC Are > > > Enabled > > > > > > "Display flickering may occur when both FBC (Frame Buffer Compression) > > > and VT - d (Intel® Virtualization Technology for Directed I/O) are enabled > > > and in use by the display controller." > > > > > > Ville found the w/a name in the database: > > > WaFbcTurnOffFbcWhenHyperVisorIsUsed:skl > > > > > > v2: Log when the quirk is applied. > > > v3: Ensure i915.enable_fbc is false when !HAS_FBC() > > > v4: Fix function name after rebase > > > > > > Signed-off-by: Chris Wilson <[email protected]> > > > Cc: Paulo Zanoni <[email protected]> > > > Cc: Ville Syrjälä <[email protected]> > > > --- > > > drivers/gpu/drm/i915/intel_fbc.c | 19 +++++++++++++++++++ > > > 1 file changed, 19 insertions(+) > > > > > > diff --git a/drivers/gpu/drm/i915/intel_fbc.c > > > b/drivers/gpu/drm/i915/intel_fbc.c > > > index 8147eb9e8475..b673c7c54a46 100644 > > > --- a/drivers/gpu/drm/i915/intel_fbc.c > > > +++ b/drivers/gpu/drm/i915/intel_fbc.c > > > @@ -1229,12 +1229,28 @@ static int intel_sanitize_fbc_option(struct > > > drm_i915_private *dev_priv) > > > if (i915.enable_fbc >= 0) > > > return !!i915.enable_fbc; > > > > > > + if (!HAS_FBC(dev_priv)) > > > + return 0; > > > + > > > if (IS_BROADWELL(dev_priv)) > > > return 1; > > > > > > return 0; > > > } > > > > > > +static bool need_fbc_wa(struct drm_i915_private *dev_priv) > > > > need_fbc_vtd_wa() perhaps? > > Right now, yes. I left it open just in case - but that's most likely a > false hope. > > > > +{ > > > +#ifdef CONFIG_INTEL_IOMMU > > > + /* WaFbcTurnOffFbcWhenHyperVisorIsUsed:skl */ > > > + if (intel_iommu_gfx_mapped && IS_SKYLAKE(dev_priv)) { > > > > BXT needs this as well AFAICS. > > Will IS_GEN9() suit? +skl,bxt in the description.
Looks like KBL doesn't need this w/a. -- Ville Syrjälä Intel OTC _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
