ACK: [SRU] [L/M] [PATCH 0/1] Fix panel brightness issues on HP laptops

[Roxana Nicolescu]

On 23/08/2023 03:03, Kai-Heng Feng wrote:
> BugLink: https://bugs.launchpad.net/bugs/2032704
>
> [Impact]
> Brightness can't be changed or can only be changed once on some modern
> HP laptops.
>
> [Fix]
> BIOS folks identified the issue where the ACPI _PS0 method isn't called
> for the panel device. On Windows the method is being invoked.
>
> This is due to missing _PSC, but since Windows is the de facto spec, we
> have to perform the same to make the device functional.
>
> [Test]
> Once the fix is applied, the brightness can be changed smoothly.
>
> [Where problems could occur]
> According to BIOS folks, Windows also invokes _PS3 for sleep and
> shutdown, we need to tackle that in the future.
> Right now not calling _PS3 has no ill-effect, per BIOS folks.
>
> Kai-Heng Feng (1):
>    ACPI: video: Put ACPI video and its child devices into D0 on boot
>
>   drivers/acpi/acpi_video.c | 6 ++++++
>   1 file changed, 6 insertions(+)
>
Acked-by: Roxana Nicolescu <roxana.nicolescu at canonical.com>