Re: [BISECTED 3.16-rc REGREGRESSION] backlight control stopped working

From: BjÃrn Mork
Date: Mon Jul 14 2014 - 17:46:43 EST


Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> writes:
> On Mon, Jul 14, 2014 at 1:45 PM, BjÃrn Mork <bjorn@xxxxxxx> wrote:
>>> brightness change from user mode comes in during that delay, we cancel
>>> the kernel-induced pending change.
>>
>> That sounds like a good solution to me FWIW.
>
> Try the patch. It *might* work. I'm not saying it will, but it seemed
> to at least compile for me.

Yes, the patch works as advertised for me. Thanks.

But this will break existing configs:

> --- a/drivers/acpi/video.c
> +++ b/drivers/acpi/video.c
> @@ -68,8 +68,8 @@ MODULE_AUTHOR("Bruno Ducrot");
> MODULE_DESCRIPTION("ACPI Video Driver");
> MODULE_LICENSE("GPL");
>
> -static bool brightness_switch_enabled;
> -module_param(brightness_switch_enabled, bool, 0644);
> +static int brightness_switch_enabled = -1;
> +module_param(brightness_switch_enabled, int, 0644);
>
> /*
> * By default, we don't allow duplicate ACPI video bus devices

Any setup using e.g "options video brightness_switch_enabled=Y" will
barf on this, won't they?


BjÃrn

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