drm/amd/display: Reduce default backlight min from 5 nits to 1 nits

[ Upstream commit 5edb7cdff85af8f8c5fda5b88310535ab823f663 ]

[Why & How]
Currently set_default_brightness_aux function uses 5 nits as lower limit
to check for valid default_backlight setting. However some newer panels
can support even lower default settings

Reviewed-by: Agustin Gutierrez <agustin.gutierrez@amd.com>
Acked-by: Roman Li <roman.li@amd.com>
Signed-off-by: Swapnil Patel <swapnil.patel@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Stable-dep-of: d9e865826c20 ("drm/amd/display: Simplify brightness initialization")
Signed-off-by: Sasha Levin <sashal@kernel.org>

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 e1708c296b7df0579d6ba029a50750fdacff6ba2..a602202610e099d8e53a32ec4df6621190656b44 100644 (file)
--- 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
@@ -281,8 +281,8 @@ bool set_default_brightness_aux(struct dc_link *link)
        if (link && link->dpcd_sink_ext_caps.bits.oled == 1) {
                if (!read_default_bl_aux(link, &default_backlight))
                        default_backlight = 150000;
-               // if < 5 nits or > 5000, it might be wrong readback
-               if (default_backlight < 5000 || default_backlight > 5000000)
+               // if < 1 nits or > 5000, it might be wrong readback
+               if (default_backlight < 1000 || default_backlight > 5000000)
                        default_backlight = 150000; //
 
                return edp_set_backlight_level_nits(link, true,