Whenever the minimum brightness is reported as 0 there are chances we maybe sometimes end up with blank screen. This confuses the user into thinking the display is acting weird. This occurs in eDP 1.5 when we are using PANEL_LUMINANCE_OVERRIDE mode to mainpulate brightness via luminance values. Make sure if minimum luminance range is 0 we program default value to max in case 0 is returned from luminance registers.
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/15671 Signed-off-by: Suraj Kandpal <[email protected]> --- v1 -> v2: - Let users set brightness to 0, make it so that it's just not done by default (Arun) drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c index eb05ef4bd9f6..c40ce310ad97 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c @@ -564,6 +564,8 @@ static int intel_dp_aux_vesa_setup_backlight(struct intel_connector *connector, } panel->backlight.level = intel_dp_aux_vesa_get_backlight(connector, 0); panel->backlight.enabled = panel->backlight.level != 0; + if (!panel->backlight.level) + panel->backlight.level = panel->backlight.max; drm_dbg_kms(display->drm, "[CONNECTOR:%d:%s] AUX VESA Nits backlight level is controlled through DPCD\n", connector->base.base.id, connector->base.name); @@ -573,6 +575,8 @@ static int intel_dp_aux_vesa_setup_backlight(struct intel_connector *connector, if (current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD) { panel->backlight.level = current_level; panel->backlight.enabled = panel->backlight.level != 0; + if (!panel->backlight.level) + panel->backlight.level = panel->backlight.max; } else { panel->backlight.level = panel->backlight.max; panel->backlight.enabled = false; -- 2.34.1
