[Intel-gfx] [intel-gfx][i-g-t][help]can't read the backlight

[Jani Nikula]

On Wed, 26 Jul 2017, "Gu, HailinX" <hailinx.gu at intel.com> wrote:
> Hi~ all,
> I try to run the test pm_backlight. But there is an skip with the log as following.
>
>
>
> ````
>
> IGT-Version: 1.19-g4258cc8e (x86_64) (Linux: 4.10.0 x86_64) Test
>
> requirement not met in function __real_main154, file pm_backlight.c:163:
>
> Test requirement: !(backlight_read(&old, "brightness")) Last errno: 2,
>
> No such file or directory
> ````
>
> By my check there is not a file in dir /sys/class/backlight/
>
> I wander is there any kconfig or boot parameters need to set?
> I have tried adding "acpi_ osi=Linux acpi_backlight=vendor" to GRUB config, but it's same as before.

Please post the dmesg, with drm.debug=14, and kernel config.

BR,
Jani.

-- 
Jani Nikula, Intel Open Source Technology Center