<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [CI][BAT] igt@gem_sync@basic-many-each - fail - Failed assertion: !"GPU hung"" href="https://bugs.freedesktop.org/show_bug.cgi?id=107715#c3">Comment # 3</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [CI][BAT] igt@gem_sync@basic-many-each - fail - Failed assertion: !"GPU hung"" href="https://bugs.freedesktop.org/show_bug.cgi?id=107715">bug 107715</a> from <a class="email" href="mailto:chris@chris-wilson.co.uk" title="Chris Wilson <chris@chris-wilson.co.uk>"> Chris Wilson</a> <pre>ARGH. The answer is I never pushed drm/i915/ringbuffer: Delay after invalidating gen6+ xcs During stress testing of full-ppgtt (on Baytrail at least), we found that the invalidation around a context/mm switch was insufficient (writes would go astray). Adding a second MI_FLUSH_DW barrier prevents this, but it is unclear as to whether this is merely a delaying tactic or if it is truly serialising with the TLB invalidation. Either way, it is empirically required. Signed-off-by: Chris Wilson <<a href="mailto:chris@chris-wilson.co.uk">chris@chris-wilson.co.uk</a>> Cc: Joonas Lahtinen <<a href="mailto:joonas.lahtinen@linux.intel.com">joonas.lahtinen@linux.intel.com</a>> Cc: Mika Kuoppala <<a href="mailto:mika.kuoppala@linux.intel.com">mika.kuoppala@linux.intel.com</a>> Cc: Matthew Auld <<a href="mailto:matthew.william.auld@gmail.com">matthew.william.auld@gmail.com</a>> Cc: Tvrtko Ursulin <<a href="mailto:tvrtko.ursulin@intel.com">tvrtko.ursulin@intel.com</a>></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 assignee for the bug.</li> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>