<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - [i915, Surface Pro 4] Regression: No display port output in kernel 4.8" href="https://bugs.freedesktop.org/show_bug.cgi?id=97991#c7">Comment # 7</a> on <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - [i915, Surface Pro 4] Regression: No display port output in kernel 4.8" href="https://bugs.freedesktop.org/show_bug.cgi?id=97991">bug 97991</a> from <a class="email" href="mailto:ville.syrjala@linux.intel.com" title="Ville Syrjala <ville.syrjala@linux.intel.com>"> Ville Syrjala</a> <pre>(In reply to Mikael Djurfeldt from <a href="show_bug.cgi?id=97991#c6">comment #6</a>) > git bisect gives fce91f2 which is about guc. > > I then realized that I had the following line in my i915.conf: > > options i915 enable_guc_submission=Y guc_log_level=3 > > When I remove these options, the display port output starts to work also for > later kernels, such as 4.8.0-rc8, i.e. the problem disappears. > > But this is still a bug, right? It seems strange that DP output disappears > just because guc is enabled. [ 9.190503] i915: `Y' invalid for parameter `enable_guc_submission' so looks like it refused to even load the module with the invalid knob in place. That behaviour is slightly amusing since you can pass non-existing modparams just fine, but apparently trying to pass an invalid value for a modparam that does exist is fatal.</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>