From: David Gow davidgow@google.com
stable inclusion from stable-v5.10.150 commit 0a4fddc95c63fa5460f778885965281360fc3d90 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I6D0XA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ 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 Signed-off-by: Jialin Zhang zhangjialin11@huawei.com --- drivers/gpu/drm/amd/display/dc/calcs/bw_fixed.c | 6 +++--- 1 file 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)