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authorDavid Gow <davidgow@google.com>2022-08-11 23:43:26 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-10-26 14:25:48 +0300
commit0a4fddc95c63fa5460f778885965281360fc3d90 (patch)
tree8a1766af5b6ed79aaea5406654419f160fb8767b
parent3959e8faf8bf6bea619e8856c736db64e6eced37 (diff)
downloadlinux-0a4fddc95c63fa5460f778885965281360fc3d90.tar.xz
drm/amd/display: fix overflow on MIN_I64 definition
[ Upstream commit 6ae0632d17759852c07e2d1e0a31c728eb6ba246 ] The definition of MIN_I64 in bw_fixed.c can cause gcc to whinge about integer overflow, because it is treated as a positive value, which is then negated. The temporary positive value is not necessarily representable. This causes the following warning: ../drivers/gpu/drm/amd/amdgpu/../display/dc/dml/calcs/bw_fixed.c:30:19: warning: integer overflow in expression ‘-9223372036854775808’ of type ‘long long int’ results in ‘-9223372036854775808’ [-Woverflow] 30 | (int64_t)(-(1LL << 63)) | ^ Writing out (-MAX_I64 - 1) works instead. Signed-off-by: David Gow <davidgow@google.com> Signed-off-by: Tales Aparecida <tales.aparecida@gmail.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--drivers/gpu/drm/amd/display/dc/calcs/bw_fixed.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/calcs/bw_fixed.c b/drivers/gpu/drm/amd/display/dc/calcs/bw_fixed.c
index 6ca288fb5fb9..2d46bc527b21 100644
--- a/drivers/gpu/drm/amd/display/dc/calcs/bw_fixed.c
+++ b/drivers/gpu/drm/amd/display/dc/calcs/bw_fixed.c
@@ -26,12 +26,12 @@
#include "bw_fixed.h"
-#define MIN_I64 \
- (int64_t)(-(1LL << 63))
-
#define MAX_I64 \
(int64_t)((1ULL << 63) - 1)
+#define MIN_I64 \
+ (-MAX_I64 - 1)
+
#define FRACTIONAL_PART_MASK \
((1ULL << BW_FIXED_BITS_PER_FRACTIONAL_PART) - 1)