<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#c19">Comment # 19</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:niklas.kielblock@googlemail.com" title="Niklas Kielblock <niklas.kielblock@googlemail.com>"> Niklas Kielblock</a> <pre>(In reply to Jani Nikula from <a href="show_bug.cgi?id=97883#c18">comment #18</a>) > Basically, we don't know how brightness is controlled on this laptop. On Windows this is handled by a kernel module separate from the main Intel graphics driver. The build for the model mentioned in this report is available at <a href="https://support.lenovo.com/en/us/downloads/ds113141">https://support.lenovo.com/en/us/downloads/ds113141</a> though some other laptops (X1 Yoga Generation 2, Alienware 13 R3) use slightly different versions of what's clearly the same codebase. 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. 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.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are on the CC list for the bug.</li> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>