On Fri, Dec 21, 2018 at 10:07:26AM +0100, Michel Dänzer wrote: > On 2018-12-21 4:10 a.m., Yu Zhao wrote: > > Userspace may request pitch alignment that is not supported by GPU. > > Some requests 32, but GPU ignores it and uses default 64 when cpp is > > 4. If GEM object is allocated based on the smaller alignment, GPU > > DMA will go out of bound. > > > > For GPU that does frame buffer compression, DMA writing out of bound > > memory will cause memory corruption. > > > > Signed-off-by: Yu Zhao <yuz...@google.com> > > --- > > drivers/gpu/drm/amd/amdgpu/amdgpu_display.c | 9 +++++++++ > > 1 file changed, 9 insertions(+) > > > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c > > b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c > > index e309d26170db..755daa332f8a 100644 > > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c > > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c > > @@ -527,6 +527,15 @@ amdgpu_display_user_framebuffer_create(struct > > drm_device *dev, > > struct drm_gem_object *obj; > > struct amdgpu_framebuffer *amdgpu_fb; > > int ret; > > + struct amdgpu_device *adev = dev->dev_private; > > + int cpp = drm_format_plane_cpp(mode_cmd->pixel_format, 0); > > + int pitch = amdgpu_align_pitch(adev, mode_cmd->width, cpp, false); > > Also, this needs to use mode_cmd->pitches instead of mode_cmd->width, > otherwise it'll spuriously fail for larger but well-aligned pitches.
Actually mode_cmd->pitches is aligned mode_cmd->width multiplied by cpp. So we can't just use mode_cmd->pitches. And I'm not sure if the hardware works with larger alignment (it certainly ignores smaller alignment). _______________________________________________ amd-gfx mailing list firstname.lastname@example.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx