From: Iswara Nagulendran <[email protected]> [How & Why] When determining default aux backlight level, read from DPCD address 0x734 for VESA SCR on OLED.
Reviewed-by: Felipe Clark <[email protected]> Acked-by: Alex Hung <[email protected]> Signed-off-by: Iswara Nagulendran <[email protected]> --- .../dc/link/protocols/link_edp_panel_control.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c index 92f58a719c07..5add2360fc94 100644 --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_edp_panel_control.c @@ -252,10 +252,20 @@ static bool read_default_bl_aux(struct dc_link *link, uint32_t *backlight_millin link->connector_signal != SIGNAL_TYPE_DISPLAY_PORT)) return false; - if (!core_link_read_dpcd(link, DP_SOURCE_BACKLIGHT_LEVEL, - (uint8_t *) backlight_millinits, - sizeof(uint32_t))) - return false; + if (!link->dpcd_caps.panel_luminance_control) { + if (!core_link_read_dpcd(link, DP_SOURCE_BACKLIGHT_LEVEL, + (uint8_t *)backlight_millinits, + sizeof(uint32_t))) + return false; + } else { + //setting to 0 as a precaution, since target_luminance_value is 3 bytes + memset(backlight_millinits, 0, sizeof(uint32_t)); + + if (!core_link_read_dpcd(link, DP_EDP_PANEL_TARGET_LUMINANCE_VALUE, + (uint8_t *)backlight_millinits, + sizeof(struct target_luminance_value))) + return false; + } return true; } -- 2.41.0
