On 2024-08-26 12:57, Mario Limonciello wrote: > On 8/24/2024 13:33, Thomas Weißschuh wrote: >> Not all platforms provide the full range of PWM backlight capabilities >> supported by the hardware through ATIF. >> Use the generic drm panel minimum backlight quirk infrastructure to >> override the capabilities where necessary. >> >> Testing the backlight quirk together with the "panel_power_savings" >> sysfs file has not shown any negative impact. >> One quirk seems to be that 0% at panel_power_savings=0 seems to be >> slightly darker than at panel_power_savings=4. > > Thanks; This is the kind of thing I was worried about. > > Harry, Leo, > > Is that expected? I wonder if we need to internally turn off panel power savings in display code when brightness falls a threshold (12 IIRC was the real "minimum" advertised in the table?). How much darker? Is it bothersome? I wonder the FW and driver have different min backlight values now. Leo, any thoughts? Harry > >> >> Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx> >> Tested-by: Dustin L. Howett <dustin@xxxxxxxxxx> >> Reviewed-by: Mario Limonciello <mario.limonciello@xxxxxxx> >> --- >> drivers/gpu/drm/amd/amdgpu/Kconfig | 1 + >> drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 10 ++++++++++ >> 2 files changed, 11 insertions(+) >> >> diff --git a/drivers/gpu/drm/amd/amdgpu/Kconfig b/drivers/gpu/drm/amd/amdgpu/Kconfig >> index 0051fb1b437f..655c10aef2e3 100644 >> --- a/drivers/gpu/drm/amd/amdgpu/Kconfig >> +++ b/drivers/gpu/drm/amd/amdgpu/Kconfig >> @@ -23,6 +23,7 @@ config DRM_AMDGPU >> select DRM_BUDDY >> select DRM_SUBALLOC_HELPER >> select DRM_EXEC >> + select DRM_PANEL_BACKLIGHT_QUIRKS >> # amdgpu depends on ACPI_VIDEO when ACPI is enabled, for select to work >> # ACPI_VIDEO's dependencies must also be selected. >> select INPUT if ACPI >> 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 983a977632ff..056960ea335c 100644 >> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c >> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c >> @@ -93,6 +93,7 @@ >> #include <drm/drm_fourcc.h> >> #include <drm/drm_edid.h> >> #include <drm/drm_eld.h> >> +#include <drm/drm_utils.h> >> #include <drm/drm_vblank.h> >> #include <drm/drm_audio_component.h> >> #include <drm/drm_gem_atomic_helper.h> >> @@ -3333,6 +3334,8 @@ static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector) >> struct drm_connector *conn_base; >> struct amdgpu_device *adev; >> struct drm_luminance_range_info *luminance_range; >> + const struct drm_edid *drm_edid; >> + int min_input_signal_override; >> if (aconnector->bl_idx == -1 || >> aconnector->dc_link->connector_signal != SIGNAL_TYPE_EDP) >> @@ -3367,6 +3370,13 @@ static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector) >> caps->aux_min_input_signal = 0; >> caps->aux_max_input_signal = 512; >> } >> + >> + drm_edid = drm_edid_alloc(aconnector->edid, >> + EDID_LENGTH * (aconnector->edid->extensions + 1)); >> + min_input_signal_override = drm_get_panel_min_brightness_quirk(drm_edid); >> + drm_edid_free(drm_edid); >> + if (min_input_signal_override >= 0) >> + caps->min_input_signal = min_input_signal_override; >> } >> void amdgpu_dm_update_connector_after_detect( >> >
