]> Gentwo Git Trees - linux/.git/commit
drm/amd/display: Fix logical vs bitwise bug in get_embedded_panel_info_v2_1()
authorDan Carpenter <dan.carpenter@linaro.org>
Fri, 31 Oct 2025 13:02:25 +0000 (16:02 +0300)
committerAlex Deucher <alexander.deucher@amd.com>
Wed, 26 Nov 2025 16:29:08 +0000 (11:29 -0500)
commit1a79482699b4d1e43948d14f0c7193dc1dcad858
tree64687a323a4fc0230de78e1a0702ac0b5e3ee3b7
parent621e55f1919640acab25383362b96e65f2baea3c
drm/amd/display: Fix logical vs bitwise bug in get_embedded_panel_info_v2_1()

The .H_SYNC_POLARITY and .V_SYNC_POLARITY variables are 1 bit bitfields
of a u32.  The ATOM_HSYNC_POLARITY define is 0x2 and the
ATOM_VSYNC_POLARITY is 0x4.  When we do a bitwise negate of 0, 2, or 4
then the last bit is always 1 so this code always sets .H_SYNC_POLARITY
and .V_SYNC_POLARITY to true.

This code is instead intended to check if the ATOM_HSYNC_POLARITY or
ATOM_VSYNC_POLARITY flags are set and reverse the result.  In other
words, it's supposed to be a logical negate instead of a bitwise negate.

Fixes: ae79c310b1a6 ("drm/amd/display: Add DCE12 bios parser support")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drivers/gpu/drm/amd/display/dc/bios/bios_parser2.c