When the laptop is plugged into AC or DC 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.
Signed-off-by: Yuanzhi Wang <wangyuanzhi@xxxxxxxxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c | 9 ++++++++-
1 file changed, 8 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..93f1567028c5 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 +444,13 @@ 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 greater than ACPI brightness
+ %d\n", old_brightness, req.backlight_level);
+ else
+ backlight_device_set_brightness(atif->bd,
+ req.backlight_level);
}
}
--
2.20.1
