04f0d6cc62
This simply adds proper support for panel backlights that can be controlled via VESA's backlight control protocol, but which also require that we enable and disable the backlight via PWM instead of via the DPCD interface. We also enable this by default, in order to fix some people's backlights that were broken by not having this enabled. For reference, backlights that require this and use VESA's backlight interface tend to be laptops with hybrid GPUs, but this very well may change in the future. v4: * Make sure that we call intel_backlight_level_to_pwm() in intel_dp_aux_vesa_enable_backlight() - vsyrjala Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://gitlab.freedesktop.org/drm/intel/-/issues/3680 Fixes: fe7d52bccab6 ("drm/i915/dp: Don't use DPCD backlights that need PWM enable/disable") Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: <stable@vger.kernel.org> # v5.12+ Link: https://patchwork.freedesktop.org/patch/msgid/20211105183342.130810-2-lyude@redhat.com
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.