drm/i915/bios: Fix parsing backlight BDB data

Starting BDB version 239, hdr_dpcd_refresh_timeout is introduced to
backlight BDB data. Commit 700034566d68 ("drm/i915/bios: Define more BDB
contents") updated the backlight BDB data accordingly. This broke the
parsing of backlight BDB data in VBT for versions 236 - 238 (both
inclusive) and hence the backlight controls are not responding on units
with the concerned BDB version.

backlight_control information has been present in backlight BDB data
from at least BDB version 191 onwards, if not before. Hence this patch
extracts the backlight_control information for BDB version 191 or newer.
Tested on Chromebooks using Jasperlake SoC (reports bdb->version = 236).
Tested on Chromebooks using Raptorlake SoC (reports bdb->version = 251).

v2: removed checking the block size of the backlight BDB data
    [vsyrjala: this is completely safe thanks to commit e163cfb4c96d
     ("drm/i915/bios: Make copies of VBT data blocks")]

Fixes: 700034566d68 ("drm/i915/bios: Define more BDB contents")
Cc: [email protected]
Cc: Jani Nikula <[email protected]>
Cc: Ville Syrjälä <[email protected]>
Signed-off-by: Karthikeyan Ramasubramanian <[email protected]>
Signed-off-by: Ville Syrjälä <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/20240221180622.v2.1.I0690aa3e96a83a43b3fc33f50395d334b2981826@changeid
Signed-off-by: Ville Syrjälä <[email protected]>

0 files changed, 0 insertions, 0 deletions