On Fri, 2024-11-29 at 08:50 +0200, Ville Syrjala wrote: > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > Mesa changed its clear color alignment from 4k to 64 bytes > without informing the kernel side about the change. This > is now likely to cause framebuffer creation to fail. > > The only thing we do with the clear color buffer in i915 is: > 1. map a single page > 2. read out bytes 16-23 from said page > 3. unmap the page > > So the only requirement we really have is that those 8 bytes > are all contained within one page. Thus we can deal with the > Mesa regression by reducing the alignment requiment from 4k > to the same 64 bytes in the kernel. We could even go as low as > 32 bytes, but IIRC 64 bytes is the hardware requirement on > the 3D engine side so matching that seems sensible. > > Cc: stable@xxxxxxxxxxxxxxx > Cc: Sagar Ghuge <sagar.ghuge@xxxxxxxxx> > Cc: Nanley Chery <nanley.g.chery@xxxxxxxxx> > Reported-by: Xi Ruoyao <xry111@xxxxxxxxxxx> > Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13057 > Closes: https://lore.kernel.org/all/45a5bba8de009347262d86a4acb27169d9ae0d9f.camel@xxxxxxxxxxx/ > Link: https://gitlab.freedesktop.org/mesa/mesa/-/commit/17f97a69c13832a6c1b0b3aad45b06f07d4b852f > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Tested-by: Xi Ruoyao <xry111@xxxxxxxxxxx> > --- > drivers/gpu/drm/i915/display/intel_fb.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_fb.c b/drivers/gpu/drm/i915/display/intel_fb.c > index 6a7060889f40..223c4218c019 100644 > --- a/drivers/gpu/drm/i915/display/intel_fb.c > +++ b/drivers/gpu/drm/i915/display/intel_fb.c > @@ -1694,7 +1694,7 @@ int intel_fill_fb_info(struct drm_i915_private *i915, struct intel_framebuffer * > * arithmetic related to alignment and offset calculation. > */ > if (is_gen12_ccs_cc_plane(&fb->base, i)) { > - if (IS_ALIGNED(fb->base.offsets[i], PAGE_SIZE)) > + if (IS_ALIGNED(fb->base.offsets[i], 64)) > continue; > else > return -EINVAL; -- Xi Ruoyao <xry111@xxxxxxxxxxx> School of Aerospace Science and Technology, Xidian University
