<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW --- - backlight switches off when starting X - since kernel-3.13" href="https://bugs.freedesktop.org/show_bug.cgi?id=75917#c12">Comment # 12</a> on <a class="bz_bug_link bz_status_NEW " title="NEW --- - backlight switches off when starting X - since kernel-3.13" href="https://bugs.freedesktop.org/show_bug.cgi?id=75917">bug 75917</a> from <a class="email" href="mailto:sebastien.fievet@free.fr" title="sfievet <sebastien.fievet@free.fr>"> sfievet</a> <pre>I am affected by this bug too. I have a Acer 3820TG laptop featuring Intel IGP (Ironlake) / AMD DGP (Radeon 6550M). It kept me stucked with kernel 3.12 series until I googled for "backlight issue" rather than "Intel driver issue" and found THIS bug report. :-) adding radeon.runpm=0 to the boot options works for me too. I haven't tested the patch yet. FWIW, I'd like to add 2 side informations hoping it might be related : - the backlight control only works for the Intel IGP. If the laptop goes idle when on the radeon, waking it up doesn't bring the backlight back. - when switching from Ironlake to Radeon through VGA switcheroo, I have to use "ON -> MIGD -> DDIS" sequence as the screen goes black immediately after passing "ON".</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>