[Intel-gfx] [PATCH] i915: Increase *_latency array size

Andi Kleen ak at linux.intel.com
Wed May 5 03:37:37 UTC 2021


From: Andi Kleen <andi at firstfloor.org>

Newer gcc prints the following warning:

drivers/gpu/drm/i915/intel_pm.c:3057:9: warning: ‘intel_print_wm_latency’ reading 16 bytes from a region of size 10 [-Wstringop-overread]
and some other related warnings in similar functions.

gcc has a point here. Some of the latency arrays only have 5 members,
but print_wm_latency may read up to max_level returned by ilk_wm_max_level,
which can be upto 7 for the >= GEN9 case.

So it will read some fields beyond the array.

Increase all the latency fields to 8 members, which is enough for SKL.

I don't know if they are correctly initialized upto 8, but dev_priv
should start out as zero, so presumably they will be zero.

Signed-off-by: Andi Kleen <andi at firstfloor.org>
---
 drivers/gpu/drm/i915/i915_drv.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index cb62ddba2035..c80add5f6d33 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1095,11 +1095,11 @@ struct drm_i915_private {
 		 * in 0.5us units for WM1+.
 		 */
 		/* primary */
-		u16 pri_latency[5];
+		u16 pri_latency[8];
 		/* sprite */
-		u16 spr_latency[5];
+		u16 spr_latency[8];
 		/* cursor */
-		u16 cur_latency[5];
+		u16 cur_latency[8];
 		/*
 		 * Raw watermark memory latency values
 		 * for SKL for all 8 levels
-- 
2.25.4



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