diff options
| author | Alessandro Rinaldi <ale@alerinaldi.it> | 2026-06-26 16:36:00 +0200 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2026-07-17 17:41:15 -0400 |
| commit | bad177fa75e607e396cd57daaaed881450d7a471 (patch) | |
| tree | f3e22afbf139b8f8e447432af385aaa299dcc7d7 /drivers/gpu | |
| parent | b240f792ae02e9b687eafff934a39e57d1e45365 (diff) | |
drm/amd/display: Force PWM backlight on Lenovo Legion 5 15ARH05
The Lenovo Legion 5 15ARH05 (Renoir) ships a BOE 0x08DF eDP panel that
advertises AUX/DPCD backlight control, so amdgpu's automatic detection
(amdgpu_backlight == -1) selects AUX. On this panel the AUX backlight
path has no effect: brightness writes are accepted but the panel level
never changes, the display is stuck at a fixed brightness and
max_brightness is reported as a bogus 511000. As a result neither the
desktop brightness slider nor the brightness hotkeys do anything.
Forcing PWM backlight (amdgpu.backlight=0) restores working control:
max_brightness becomes 65535 and the level tracks writes. This has long
been applied by users as a manual kernel-parameter workaround.
Extend the generic panel backlight quirk with a force_pwm flag, add an
entry for the Legion 5 15ARH05 / BOE 0x08DF panel, and have amdgpu
disable AUX backlight (use PWM) when the quirk matches and the user
lets the driver auto-select the backlight type.
Signed-off-by: Alessandro Rinaldi <ale@alerinaldi.it>
Tested-by: Alessandro Rinaldi <ale@alerinaldi.it>
Reviewed-by: George Zhang <george.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 81b39f43e7e53589491e2eef6bad5389626b4b9c)
Cc: stable@vger.kernel.org
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 7 | ||||
| -rw-r--r-- | drivers/gpu/drm/drm_panel_backlight_quirks.c | 9 |
2 files changed, 14 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 fe6eea28d119..6210a1ff7cc2 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -4069,6 +4069,8 @@ static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector) caps->ext_caps = &aconnector->dc_link->dpcd_sink_ext_caps; caps->aux_support = false; + panel_backlight_quirk = drm_get_panel_backlight_quirk(aconnector->drm_edid); + if (caps->ext_caps->bits.oled == 1 /* * || @@ -4081,6 +4083,9 @@ static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector) caps->aux_support = false; else if (amdgpu_backlight == 1) caps->aux_support = true; + else if (!IS_ERR_OR_NULL(panel_backlight_quirk) && + panel_backlight_quirk->force_pwm) + caps->aux_support = false; if (caps->aux_support) aconnector->dc_link->backlight_control_type = BACKLIGHT_CONTROL_AMD_AUX; @@ -4096,8 +4101,6 @@ static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector) else caps->aux_min_input_signal = 1; - panel_backlight_quirk = - drm_get_panel_backlight_quirk(aconnector->drm_edid); if (!IS_ERR_OR_NULL(panel_backlight_quirk)) { if (panel_backlight_quirk->min_brightness) { caps->min_input_signal = diff --git a/drivers/gpu/drm/drm_panel_backlight_quirks.c b/drivers/gpu/drm/drm_panel_backlight_quirks.c index f85cb293a3db..e417c7533053 100644 --- a/drivers/gpu/drm/drm_panel_backlight_quirks.c +++ b/drivers/gpu/drm/drm_panel_backlight_quirks.c @@ -20,6 +20,15 @@ struct drm_get_panel_backlight_quirk { }; static const struct drm_get_panel_backlight_quirk drm_panel_min_backlight_quirks[] = { + /* Lenovo Legion 5 15ARH05, AUX backlight non-functional, force PWM */ + { + .dmi_match.field = DMI_SYS_VENDOR, + .dmi_match.value = "LENOVO", + .dmi_match_other.field = DMI_PRODUCT_VERSION, + .dmi_match_other.value = "Lenovo Legion 5 15ARH05", + .ident.panel_id = drm_edid_encode_panel_id('B', 'O', 'E', 0x08df), + .quirk = { .force_pwm = true, }, + }, /* 13 inch matte panel */ { .dmi_match.field = DMI_BOARD_VENDOR, |