On 2/27/23 01:39, Yuanzhi Wang wrote:
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.
Do you have a matching bug report with more information included? Some relevant details I think we need: kernel version laptop model BIOS version if it's the latest BIOS some sample numbers that this new warning/behavior catches acpidump At least as described this sounds like a BIOS bug.
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); } }
