<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW --- - drm:i915_hangcheck_elapsed on 3.11.6-4-desktop" href="https://bugs.freedesktop.org/show_bug.cgi?id=73261#c13">Comment # 13</a> on <a class="bz_bug_link bz_status_NEW " title="NEW --- - drm:i915_hangcheck_elapsed on 3.11.6-4-desktop" href="https://bugs.freedesktop.org/show_bug.cgi?id=73261">bug 73261</a> from <a class="email" href="mailto:chris@chris-wilson.co.uk" title="Chris Wilson <chris@chris-wilson.co.uk>"> Chris Wilson</a> <pre>Interesting. It looks like there was a CPU access that overwrote the first few megabytes of video RAM after i915.ko was loaded but before X started. The hang occurs because we write some instructions into the ring early which are overwritten before we execute the first batch (the actual instructions for the batches are fine). Since we do not appear to overwrite any batches, that leads me to the conclusion that it is not the GPU (following invalid userspace commands) doing the overwriting, but access by the CPU. Ergo this is a nasty BIOS bug, and most likely prevented by a working fastboot or bios update.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are on the CC list for the bug.</li> </ul> </body> </html>