Commit 1d550333 authored by Colin Ian King's avatar Colin Ian King Committed by Alex Deucher
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drm/amd/display: fix potential integer overflow when shifting 32 bit variable bl_pwm 



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: 3ba01817 ("drm/amd/display: Move panel_cntl specific register from abm to panel_cntl.")
Signed-off-by: default avatarColin Ian King <colin.king@canonical.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 367deb67

drivers/gpu/drm/amd/display/dc/dce/dce_panel_cntl.c

+1 −1
Original line number Diff line number Diff line
@@ -76,7 +76,7 @@ static unsigned int dce_get_16_bit_backlight_from_pwm(struct panel_cntl *panel_c 
	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;