From 4819d16d91145966ce03818a95169df1fd56b299 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
Date: Wed, 21 Apr 2021 18:33:58 +0300
Subject: [PATCH] drm/i915: Avoid div-by-zero on gen2
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Git-commit: 4819d16d91145966ce03818a95169df1fd56b299
Patch-mainline: v5.13-rc2
Alt-commit: ed52c62d386f764194e0184fdb905d5f24194cae
References: git-fixes
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 6846895fde05 ("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: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210421153401.13847-2-ville.syrjala@linux.intel.com
(cherry picked from commit ed52c62d386f764194e0184fdb905d5f24194cae)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/i915/gem/i915_gem_mman.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
index 23f6b00e08e2..f6fe5cb01438 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
@@ -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);
--
2.26.2