5.15-stable review patch. If anyone has any objections, please let me know.
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From: Ville Syrjälä ville.syrjala@linux.intel.com
commit 1a5401ec3018c101c456cdbda2eaef9482db6786 upstream.
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.
Note that the Mesa alignment chages were partially undone so the regression itself was already fixed on userspace side.
Cc: stable@vger.kernel.org Cc: Sagar Ghuge sagar.ghuge@intel.com Cc: Nanley Chery nanley.g.chery@intel.com Reported-by: Xi Ruoyao xry111@xry111.site Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13057 Closes: https://lore.kernel.org/all/45a5bba8de009347262d86a4acb27169d9ae0d9f.camel@x... Link: https://gitlab.freedesktop.org/mesa/mesa/-/commit/17f97a69c13832a6c1b0b3aad4... Link: https://gitlab.freedesktop.org/mesa/mesa/-/commit/888f63cf1baf34bc95e847a30a... Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20241129065014.8363-2-ville.sy... Tested-by: Xi Ruoyao xry111@xry111.site Reviewed-by: José Roberto de Souza jose.souza@intel.com (cherry picked from commit ed3a892e5e3d6b3f6eeb76db7c92a968aeb52f3d) Signed-off-by: Tvrtko Ursulin tursulin@ursulin.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/i915/display/intel_fb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/gpu/drm/i915/display/intel_fb.c +++ b/drivers/gpu/drm/i915/display/intel_fb.c @@ -795,7 +795,7 @@ int intel_fill_fb_info(struct drm_i915_p * 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;