On Tue, Jan 29, 2019 at 03:31:21PM +0200, Jani Nikula wrote: > We've supported the opregion RVDA/RVDS fields for VBT size >= 6 KB since > commit 04ebaadb9f2d ("drm/i915/opregion: handle VBT sizes bigger than 6 > KB"). That's three years, almost to the date. > > The implementation was based on spec only, in anticipation of systems > with big VBT. Now, the spec has been changed. The RVDA is supposed to be > relative from the beginning of opregion, not absolute address. > > This is obviously a backward/forward incompatible change. I've been told > there are no systems out there using the field. Fingers crossed. This > will still be problematic for older kernels, and we can only try to > backport the fix. > > Fix the error path while at it. > > Fixes: 04ebaadb9f2d ("drm/i915/opregion: handle VBT sizes bigger than 6 KB") > Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > Cc: Imre Deak <imre.deak@xxxxxxxxx> > Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > --- > drivers/gpu/drm/i915/intel_opregion.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c > index 30ae96c5c97c..30324b963e24 100644 > --- a/drivers/gpu/drm/i915/intel_opregion.c > +++ b/drivers/gpu/drm/i915/intel_opregion.c > @@ -118,7 +118,7 @@ struct opregion_asle { > u64 fdss; > u32 fdsp; > u32 stat; > - u64 rvda; /* Physical address of raw vbt data */ > + u64 rvda; /* Address of raw vbt data, relative from opregion */ > u32 rvds; /* Size of raw vbt data */ > u8 rsvd[58]; > } __packed; > @@ -954,7 +954,13 @@ int intel_opregion_setup(struct drm_i915_private *dev_priv) > > if (opregion->header->opregion_ver >= 2 && opregion->asle && > opregion->asle->rvda && opregion->asle->rvds) { > - opregion->rvda = memremap(opregion->asle->rvda, > + /* > + * rvda is unsigned, relative from opregion base, and should > + * never point within opregion. > + */ > + WARN_ON(opregion->asle->rvda < OPREGION_SIZE); > + > + opregion->rvda = memremap(asls + opregion->asle->rvda, > opregion->asle->rvds, > MEMREMAP_WB); > vbt = opregion->rvda; > @@ -966,6 +972,8 @@ int intel_opregion_setup(struct drm_i915_private *dev_priv) > goto out; > } else { > DRM_DEBUG_KMS("Invalid VBT in ACPI OpRegion (RVDA)\n"); > + memunmap(opregion->rvda); > + opregion->rvda = NULL; > } > } > > -- > 2.20.1 -- Ville Syrjälä Intel _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx