[patch] Testing the new i915 driver (rev. 3820047)

[Ranjan1018 .]

2015-10-21 23:56 GMT+02:00 Henry Hu <henry.hu.sh at gmail.com>:

>
>
>
> On Wed, Oct 21, 2015 at 3:09 PM, Ranjan1018 . <214748mv at gmail.com> wrote:
>
>> Backlight support for the i915 driver via sysctl.
>>
>> Instructions:
>>     Install the attached patch :
>>
>>  # cd freebsd-base-graphics
>>  # patch -p2  <  i915_backlight.patch
>>
>>     Rebuild, install and reboot the new kernel.
>>
>> Now you can control the backlight of your laptop via sysctl:
>>
>>     set backlight to 10%
>>
>> # sysctl hw.dri.0.i915_backlight=10
>> hw.dri.0.i915_backlight: 9 -> 10
>>
>>     set backlight to 20%
>>
>> # sysctl hw.dri.0.i915_backlight=20
>> hw.dri.0.i915_backlight: 10 -> 20
>>
>>     increment the backlight
>>
>> # sysctl -n hw.dri.0.i915_backlight=1000
>> 20 -> 25
>>
>>     decrement the backlight
>>
>> # sysctl -n hw.dri.0.i915_backlight=-1000
>> 25 -> 20
>>
>>     decrement the backlight
>>
>> # sysctl hw.dri.0.i915_backlight=-1000
>> hw.dri.0.i915_backlight: 20 -> 16
>>
>> You can also set the initial backlight at boot in /boot/loader.conf :
>>
>> drm.i915.init_backlight=10
>>
>> or via /etc/sysctl.conf
>>
>> hw.dri.0.i915_backlight=10
>>
>> set a 10% backlight.
>>
>> I am running this patch on current for months on my Samsung Samsung ATIV
>> Book 2 270E5E with Intel HD Graphics 4000.
>>
>
> You can try graphics/intel-backlight, which does not require a kernel
> patch.
>

I know graphics/intel-backlight, I have first ported intel-backlight to
FreeBSD :-)
(and Grembo has done a great job to build a port) or you can try my updated
version on github https://github.com/maurizio-emmex/intel_backlight_fbsd to
fine control the backlight modifying directly the hardware register.

But, IMHO the i915 driver, should be able to change its own backlight
without external program or additional drivers.

Regards,
Maurizio (emmex)