Re: [PATCH] ACPI: disable the ACPI backlight control on laptops with buggy _BCL methods

Matthew Garrett
2009-01-08T03:32:58Z

On Thu, Jan 08, 2009 at 10:58:16AM +0800, Zhang Rui wrote:

> Some users used to control the backlight via the platform interface.
> But commit c3d6de698c84efdbdd3781b7058bcc339ab43da8 disables the platform
> backlight control if ACPI video backlight control is available.
>
> This breaks the laptops with buggy _BCL/_BCM/_BQC methods. i.e. only ACPI
> backlight I/F are available on these laptops but they don't work.
>
> With this patch applied, the ACPI backlight control are disabled instead
> on these laptops.

Why? These all seem to behave consistently, so I can't see any problem
with us simply adding support for this varient. Disabling the ACPI
control when we have no idea whether there's a platform driver available
for the machine doesn't seem like the right fix.

--
Matthew Garrett | mjg59@srcf.ucam.org