diff options
| author | Dan Carpenter <dan.carpenter@linaro.org> | 2025-10-31 16:02:25 +0300 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2025-11-26 11:29:08 -0500 |
| commit | 1a79482699b4d1e43948d14f0c7193dc1dcad858 (patch) | |
| tree | 64687a323a4fc0230de78e1a0702ac0b5e3ee3b7 /drivers/gpu/drm/amd/display | |
| parent | 621e55f1919640acab25383362b96e65f2baea3c (diff) | |
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>
Diffstat (limited to 'drivers/gpu/drm/amd/display')
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/bios/bios_parser2.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/bios/bios_parser2.c b/drivers/gpu/drm/amd/display/dc/bios/bios_parser2.c index 04eb647acc4e..550a9f1d03f8 100644 --- a/drivers/gpu/drm/amd/display/dc/bios/bios_parser2.c +++ b/drivers/gpu/drm/amd/display/dc/bios/bios_parser2.c @@ -1480,10 +1480,10 @@ static enum bp_result get_embedded_panel_info_v2_1( /* not provided by VBIOS */ info->lcd_timing.misc_info.HORIZONTAL_CUT_OFF = 0; - info->lcd_timing.misc_info.H_SYNC_POLARITY = ~(uint32_t) (lvds->lcd_timing.miscinfo - & ATOM_HSYNC_POLARITY); - info->lcd_timing.misc_info.V_SYNC_POLARITY = ~(uint32_t) (lvds->lcd_timing.miscinfo - & ATOM_VSYNC_POLARITY); + info->lcd_timing.misc_info.H_SYNC_POLARITY = !(lvds->lcd_timing.miscinfo & + ATOM_HSYNC_POLARITY); + info->lcd_timing.misc_info.V_SYNC_POLARITY = !(lvds->lcd_timing.miscinfo & + ATOM_VSYNC_POLARITY); /* not provided by VBIOS */ info->lcd_timing.misc_info.VERTICAL_CUT_OFF = 0; |