c05d8332f5
We have now seen panel (XMG Core 15 e21 laptop) advertizing support
for Intel proprietary eDP backlight control via DPCD registers, but
actually working only with legacy pwm control.
This patch adds panel EDID check for possible HDR static metadata and
Intel proprietary eDP backlight control is used only if that exists.
Missing HDR static metadata is ignored if user specifically asks for
Intel proprietary eDP backlight control via enable_dpcd_backlight
parameter.
v2 :
- Ignore missing HDR static metadata if Intel proprietary eDP
backlight control is forced via i915.enable_dpcd_backlight
- Printout info message if panel is missing HDR static metadata and
support for Intel proprietary eDP backlight control is detected
Fixes: 4a8d79901d5b ("drm/i915/dp: Enable Intel's HDR backlight interface (only SDR for now)")
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/5284
Cc: Lyude Paul <lyude@redhat.com>
Cc: Mika Kahola <mika.kahola@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Filippo Falezza <filippo.falezza@outlook.it>
Cc: stable@vger.kernel.org
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220413082826.120634-1-jouni.hogander@intel.com
Reviewed-by: Lyude Paul <lyude@redhat.com>
(cherry picked from commit b4b157577cb1de13bee8bebc3576f1de6799a921)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.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.