| Message ID | 1485521860-682-1-git-send-email-harry.pan@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c index 08ab6d7..e882139 100644 --- a/drivers/gpu/drm/i915/intel_panel.c +++ b/drivers/gpu/drm/i915/intel_panel.c @@ -1104,7 +1104,7 @@ void intel_panel_enable_backlight(struct intel_connector *connector) WARN_ON(panel->backlight.max == 0); - if (panel->backlight.level <= panel->backlight.min) { + if (panel->backlight.level < panel->backlight.min) { panel->backlight.level = panel->backlight.max; if (panel->backlight.device) panel->backlight.device->props.brightness =
When enabling panel backlight, if the current backlight level setting matches the panel's minimal, it would apply default policy to override the current level by the panel's maximum until next request to update brightness, this leads unexpected user confusion with temporary full power backlight. This odd could be reproduced as commands like these: $ xbacklight -set 0 $ sudo sh -c 'echo mem > /sys/power/state' (resume) To fix this, slightly tinker the backlight level comparison from 'less-and-equal-to' to 'less-than'. Before: (dmesg | grep backlight # with drm.debug=0xe) [ 82.249265] [drm:intel_backlight_device_update_status [i915]] updating intel_backlight, brightness=0/5273 [ 82.249282] [drm:intel_panel_actually_set_backlight [i915]] set backlight PWM = 207 [ 82.249306] [drm:intel_edp_backlight_power [i915]] panel power control backlight disable [ 92.066041] [drm:intel_edp_backlight_off [i915]] [ 92.270489] [drm:intel_panel_actually_set_backlight [i915]] set backlight PWM = 0 [ 94.080434] [drm:intel_edp_backlight_on.part.25 [i915]] [ 94.080476] [drm:intel_panel_enable_backlight [i915]] pipe A [ 94.080539] [drm:intel_panel_actually_set_backlight [i915]] set backlight PWM = 5273 After: [ 72.874465] [drm:intel_backlight_device_update_status [i915]] updating intel_backlight, brightness=0/5273 [ 72.874499] [drm:intel_panel_actually_set_backlight [i915]] set backlight PWM = 207 [ 72.874540] [drm:intel_edp_backlight_power [i915]] panel power control backlight disable [ 86.807928] [drm:intel_edp_backlight_off [i915]] [ 87.013227] [drm:intel_panel_actually_set_backlight [i915]] set backlight PWM = 0 [ 89.001829] [drm:intel_edp_backlight_on.part.25 [i915]] [ 89.001859] [drm:intel_panel_enable_backlight [i915]] pipe A [ 89.001926] [drm:intel_panel_actually_set_backlight [i915]] set backlight PWM = 207 Fixes: 13f3fbe827d0 ("fix inconsistent brightness after resume") Signed-off-by: Harry Pan <harry.pan@intel.com> --- drivers/gpu/drm/i915/intel_panel.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)