From 9c2883057b3c861879b647f34e8bc448954e8729 Mon Sep 17 00:00:00 2001 From: Lauri Tirkkonen Date: Mon, 21 Jul 2025 09:59:40 +0900 Subject: [PATCH] drm/amd/display: fix initial backlight brightness calculation DIV_ROUND_CLOSEST(x, 100) returns either 0 or 1 if 0 Cc: stable@vger.kernel.org Reviewed-by: Mario Limonciello Link: https://lore.kernel.org/r/aH2Q_HJvxKbW74vU@hacktheplanet.fi Signed-off-by: Mario Limonciello Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) 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 096b23ad4845..468c9c5a6773 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -4983,9 +4983,9 @@ amdgpu_dm_register_backlight_device(struct amdgpu_dm_connector *aconnector) caps = &dm->backlight_caps[aconnector->bl_idx]; if (get_brightness_range(caps, &min, &max)) { if (power_supply_is_system_supplied() > 0) - props.brightness = (max - min) * DIV_ROUND_CLOSEST(caps->ac_level, 100); + props.brightness = DIV_ROUND_CLOSEST((max - min) * caps->ac_level, 100); else - props.brightness = (max - min) * DIV_ROUND_CLOSEST(caps->dc_level, 100); + props.brightness = DIV_ROUND_CLOSEST((max - min) * caps->dc_level, 100); /* min is zero, so max needs to be adjusted */ props.max_brightness = max - min; drm_dbg(drm, "Backlight caps: min: %d, max: %d, ac %d, dc %d\n", min, max, -- 2.25.1