diff options
| author | Suraj Kandpal <suraj.kandpal@intel.com> | 2026-04-07 08:37:11 +0530 |
|---|---|---|
| committer | Tvrtko Ursulin <tursulin@ursulin.net> | 2026-04-14 08:04:44 +0100 |
| commit | ed8be780bdbc9f7727553b9fa6951f5c38b0a15b (patch) | |
| tree | 11fa88838416255c7883dfe915c9b10d8bbddb24 /drivers/gpu | |
| parent | 83e8d8bbffa8161e94f3aeee4dd09a35062a78c8 (diff) | |
drm/i915/backlight: Fix VESA backlight possible check condition
VESA backlight enable is possible when
BACKLIGHT_AUX_ENABLE_CAPABLE is true via AUX command or when
BACKLIGHT_PIN_ENABLE_CAPABLE is true via eDP connector pin.
Similarly, backlight brightness adjustment can be
done via AUX-based control or PWM pin-based control.
It means there can be three configurations:
1) Full AUX-based: Enable and adjustment both via AUX. We currently
support this (apart from the AUX luminance-based backlight control).
2) Hybrid: Enable via the BL_ENABLE pin, adjustment via either AUX or
PWM.
3) Fully PWM pin-based: Enable via the BL_ENABLE pin, adjustment via
PWM.
Since that only 1 is supported as of now we need to make
sure we do not try to manipulate backlight when
BACKLIGHT_AUX_ENABLE_CAPABLE is not set.
Also fix return value when condition is not fulfilled.
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/work_items/15907
Fixes: 0fb03890d182 ("drm/i915/backlight: Check if VESA backlight is possible")
Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patch.msgid.link/20260407030710.1440046-1-suraj.kandpal@intel.com
(cherry picked from commit 102d44b3a8fad96e94e9ccd0579986c14a1f2f75)
Signed-off-by: Tvrtko Ursulin <tursulin@ursulin.net>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 9 |
1 files changed, 7 insertions, 2 deletions
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 d0c76632a946..a8d56ebf06a2 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c @@ -615,8 +615,13 @@ check_if_vesa_backlight_possible(struct intel_dp *intel_dp) int ret; u8 bit_min, bit_max; - if (!(intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP)) - return true; + /* + * Since we only support Fully AUX Based VESA Backlight interface make sure + * backlight enable is possible via AUX along with backlight adjustment + */ + if (!(intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP && + intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP)) + return false; ret = drm_dp_dpcd_read_byte(&intel_dp->aux, DP_EDP_PWMGEN_BIT_COUNT_CAP_MIN, &bit_min); if (ret < 0) |