From eaf56410ccb06f4af9475b7018ec46aa022ee99e Mon Sep 17 00:00:00 2001 From: Leo Li Date: Mon, 21 Oct 2019 14:58:47 -0400 Subject: drm/amdgpu: Add DC feature mask to disable fractional pwm MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [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 Reviewed-by: Anthony Koo Tested-by: Lukáš Krejčí Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/include/amd_shared.h | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/gpu/drm/amd/include/amd_shared.h') diff --git a/drivers/gpu/drm/amd/include/amd_shared.h b/drivers/gpu/drm/amd/include/amd_shared.h index 8340ec0ab792..dc7eb28f0296 100644 --- a/drivers/gpu/drm/amd/include/amd_shared.h +++ b/drivers/gpu/drm/amd/include/amd_shared.h @@ -143,6 +143,7 @@ enum PP_FEATURE_MASK { enum DC_FEATURE_MASK { DC_FBC_MASK = 0x1, DC_MULTI_MON_PP_MCLK_SWITCH_MASK = 0x2, + DC_DISABLE_FRACTIONAL_PWM_MASK = 0x4, DC_PSR_MASK = 0x8, }; -- cgit