Commit ed52c62d authored by Ville Syrjälä's avatar Ville Syrjälä
Browse files

drm/i915: Avoid div-by-zero on gen2 



Gen2 tiles are 2KiB in size so i915_gem_object_get_tile_row_size()
can in fact return <4KiB, which leads to div-by-zero here.
Avoid that.

Not sure i915_gem_object_get_tile_row_size() is entirely
sane anyway since it doesn't account for the different tile
layouts on i8xx/i915...

I'm not able to hit this before commit 6846895f ("drm/i915:
Replace PIN_NONFAULT with calls to PIN_NOEVICT") and it looks
like I also need to run recent version of Mesa. With those in
place xonotic trips on this quite easily on my 85x.

Cc: stable@vger.kernel.org
Reviewed-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210421153401.13847-2-ville.syrjala@linux.intel.com
parent f1f7f553

drivers/gpu/drm/i915/gem/i915_gem_mman.c

+1 −1
Original line number Diff line number Diff line
@@ -189,7 +189,7 @@ compute_partial_view(const struct drm_i915_gem_object *obj, 
	struct i915_ggtt_view view;



	if (i915_gem_object_is_tiled(obj))

		chunk = roundup(chunk, tile_row_pages(obj));

		chunk = roundup(chunk, tile_row_pages(obj) ?: 1);



	view.type = I915_GGTT_VIEW_PARTIAL;

	view.partial.offset = rounddown(page_offset, chunk);