<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_REOPENED " title="REOPENED - [i915] intel_backlight does not function - Lenovo X1 Yoga OLED" href="https://bugs.freedesktop.org/show_bug.cgi?id=97883#c25">Comment # 25</a> on <a class="bz_bug_link bz_status_REOPENED " title="REOPENED - [i915] intel_backlight does not function - Lenovo X1 Yoga OLED" href="https://bugs.freedesktop.org/show_bug.cgi?id=97883">bug 97883</a> from <a class="email" href="mailto:jani.nikula@intel.com" title="Jani Nikula <jani.nikula@intel.com>"> Jani Nikula</a> <pre>(In reply to Niklas Kielblock from <a href="show_bug.cgi?id=97883#c19">comment #19</a>) > The download above contains debug symbols, so I've done some cursory > analysis. It communicates with the panel via eDP AUX (couldn't say if it's > using I2C-over-AUX, though) through an interface exposed by the primary > Intel graphics driver. References to gamma and voltages (ELVSS) indicate > it's considerably more low-level. The panel's DPCD indicates that it doesn't support the DP standard native aux backlight control (see <a href="show_bug.cgi?id=97883#c7">comment #7</a>). It seems like some proprietary sauce. > It's developed by Intel, not a third-party manufacturer; I have no insight > into your organisation so forgive me if I'm wrong but I would imagine you > can inquire about this internally. Suffice it to say, it's not just tracking this down, it's also getting the permission to open source something that the display vendor apparently deemed best to do in their own proprietary way instead of following the DP specs.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> <li>You are on the CC list for the bug.</li> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>