From: Colin Ian King colin.king@canonical.com
[ Upstream commit 1d5503331b12a76266049289747dfd94f1643fde ]
The 32 bit unsigned integer bl_pwm is being shifted using 32 bit arithmetic and then being assigned to a 64 bit unsigned integer. There is a potential for a 32 bit overflow so cast bl_pwm to enforce a 64 bit shift operation to avoid this.
Addresses-Coverity: ("unintentional integer overflow") Fixes: 3ba01817365c ("drm/amd/display: Move panel_cntl specific register from abm to panel_cntl.") Signed-off-by: Colin Ian King colin.king@canonical.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/display/dc/dce/dce_panel_cntl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_panel_cntl.c b/drivers/gpu/drm/amd/display/dc/dce/dce_panel_cntl.c index ebff9b1e312e5..124c081a0f2ca 100644 --- a/drivers/gpu/drm/amd/display/dc/dce/dce_panel_cntl.c +++ b/drivers/gpu/drm/amd/display/dc/dce/dce_panel_cntl.c @@ -75,7 +75,7 @@ static unsigned int calculate_16_bit_backlight_from_pwm(struct dce_panel_cntl *d else bl_pwm &= 0xFFFF;
- current_backlight = bl_pwm << (1 + bl_int_count); + current_backlight = (uint64_t)bl_pwm << (1 + bl_int_count);
if (bl_period == 0) bl_period = 0xFFFF;