[PATCH v2] acpi-video: Add a parameter to not register the backlight sysfs interface

[Hans de Goede]

Hi,

On 11-06-15 13:10, Jani Nikula wrote:
> On Thu, 11 Jun 2015, Hans de Goede <hdegoede at redhat.com> wrote:
>> Hi,
>>
>> On 11-06-15 03:43, Aaron Lu wrote:
>>> On Tue, Jun 09, 2015 at 11:54:45PM +0200, Hans de Goede wrote:
>>>> Hi,
>>>>
>>>> On 06/09/2015 11:10 AM, Aaron Lu wrote:
>>>>> On Tue, Jun 09, 2015 at 10:32:25AM +0200, Hans de Goede wrote:
>>>>>> On some systems acpi-video backlight is broken in the sense that it cannot
>>>>>> control the brightness of the backlight, but it must still be called on
>>>>>> resume to power-up the backlight after resume.
>>>>>
>>>>> All the video module does on resume is a backlight set operation, it
>>>>> can't control backlight but can turn on the screen on resume? Hmm...
>>>>>
>>>>> I'll ask Sylvain to attach acpidump, let's see if there is anything
>>>>> special there.
>>>>
>>>> Ok, lets see what comes out of that. Note in the mean time Sylvain has
>>>> attached his acpidump.
>>>
>>> Thanks.
>>> According to the discussion in the bugzilla place, it doesn't seem we
>>> have any other way to handle this at the moment.
>>>
>>> Acked-by: Aaron Lu <aaron.lu at intel.com>
>>
>> Thanks. So that only leaves Jani's remark:
>>
>>   > Nitpick, I'd prefer positively named variables, like enable_foo to avoid
>>   > the double negative !disable_foo. enable_foo and !enable_foo read much
>>   > better. But up to Aaron and friends.
>>
>> I personally believe that having the option named disable_backlight_sysfs_if
>> is better here since I believe that things which are always enabled except
>> on a few broken model laptops the option name should be disable_foo so
>> that people can clearly see in /proc/cmdline / dmesg that the user is passing
>> an option to disable something which is normally enabled.
>
> Fair enough.
>
>>
>> As for the (!disabled) argument, the code in question here actually is:
>>
>> if (disabled)
>> 	return 0;
>>
>> :)
>>
>> Still if people want me to change the option to a default-on
>> enable_backlight_sysfs_if option I can do a v3...
>
> I'm not insisting.

Great, thanks :)

So I'm going to assume this v2 patch is ready for merging then, if anyone
wants me to make any changes please let me know.

Regards,

Hans