There is a lenovo ThinkBook 14 G3 ACL notebook, when the laptop is plugged into AC power supply, the brightness obtained ACPI may be smaller than current brightness.As a result the screen becomes dark,this is not what people want. So we should add So we should filter out very small brightness values obtained from ACPI Signed-off-by: Yuanzhi Wang <wangyuanzhi@xxxxxxxxxxxxx> --- drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c index d4196fcb85a0..20e7a178765d 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c @@ -406,6 +406,7 @@ static int amdgpu_atif_handler(struct amdgpu_device *adev, { struct amdgpu_atif *atif = &amdgpu_acpi_priv.atif; int count; + int old_brightness; DRM_DEBUG_DRIVER("event, device_class = %s, type = %#x\n", event->device_class, event->type); @@ -443,7 +444,14 @@ static int amdgpu_atif_handler(struct amdgpu_device *adev, * hardwired to post BACKLIGHT_UPDATE_SYSFS. * It probably should accept 'reason' parameter. */ - backlight_device_set_brightness(atif->bd, req.backlight_level); + old_brightness = backlight_get_brightness(atif->bd); + if (old_brightness > req.backlight_level) + DRM_WARN( + "Old brightness %d is larger than ACPI brightness %d\n", + old_brightness, req.backlight_level); + else + backlight_device_set_brightness(atif->bd, + req.backlight_level); } } -- 2.20.1