diff options
| author | Leo Li <sunpeng.li@amd.com> | 2019-10-21 14:58:47 -0400 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2019-10-25 16:50:10 -0400 |
| commit | eaf56410ccb06f4af9475b7018ec46aa022ee99e (patch) | |
| tree | 705819a2b47e610e74e11ba63f7a7017dc6110db /drivers/gpu/drm/amd/display | |
| parent | 9f0256da6ba0fbe05f4e86d5b1153f89b54c5fd4 (diff) | |
| download | linux-eaf56410ccb06f4af9475b7018ec46aa022ee99e.tar.bz2 | |
drm/amdgpu: Add DC feature mask to disable fractional pwm
[Why]
Some LED panel drivers might not like fractional PWM. In such cases,
backlight flickering may be observed.
[How]
Add a DC feature mask to disable fractional PWM, and associate it with
the preexisting dc_config flag.
The flag is only plumbed through the dmcu firmware, so plumb it through
the driver path as well.
To disable, add the following to the linux cmdline:
amdgpu.dcfeaturemask=0x4
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=204957
Signed-off-by: Leo Li <sunpeng.li@amd.com>
Reviewed-by: Anthony Koo <anthony.koo@amd.com>
Tested-by: Lukáš Krejčí <lskrejci@gmail.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/amdgpu_dm/amdgpu_dm.c | 3 | ||||
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/dce/dce_abm.c | 4 |
2 files changed, 7 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 854d2caf18dd..620abe29ef08 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -728,6 +728,9 @@ static int amdgpu_dm_init(struct amdgpu_device *adev) if (amdgpu_dc_feature_mask & DC_MULTI_MON_PP_MCLK_SWITCH_MASK) init_data.flags.multi_mon_pp_mclk_switch = true; + if (amdgpu_dc_feature_mask & DC_DISABLE_FRACTIONAL_PWM_MASK) + init_data.flags.disable_fractional_pwm = true; + init_data.flags.power_down_display_on_boot = true; #ifdef CONFIG_DRM_AMD_DC_DCN2_0 diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c b/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c index d759fdca7fdb..b8a3fc505c9b 100644 --- a/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c +++ b/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c @@ -404,6 +404,10 @@ static bool dce_abm_init_backlight(struct abm *abm) /* Enable the backlight output */ REG_UPDATE(BL_PWM_CNTL, BL_PWM_EN, 1); + /* Disable fractional pwm if configured */ + REG_UPDATE(BL_PWM_CNTL, BL_PWM_FRACTIONAL_EN, + abm->ctx->dc->config.disable_fractional_pwm ? 0 : 1); + /* Unlock group 2 backlight registers */ REG_UPDATE(BL_PWM_GRP1_REG_LOCK, BL_PWM_GRP1_REG_LOCK, 0); |