From: Colin Ian King <[email protected]>

[ 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 <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
 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;
-- 
2.25.1



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