<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [gen4] GPU crash - segfault at error in chrome" href="https://bugs.freedesktop.org/show_bug.cgi?id=88739#c6">Comment # 6</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [gen4] GPU crash - segfault at error in chrome" href="https://bugs.freedesktop.org/show_bug.cgi?id=88739">bug 88739</a> from <a class="email" href="mailto:mattst88@gmail.com" title="Matt Turner <mattst88@gmail.com>"> Matt Turner</a> <pre>I suspect this may be another duplicate of the bug fixed (worked-around) by this commit: commit c4fd0c9052dd391d6f2e9bb8e6da209dfc7ef35b Author: Kenneth Graunke <<a href="mailto:kenneth@whitecape.org">kenneth@whitecape.org</a>> Date: Sat Jan 17 23:21:15 2015 -0800 i965: Work around mysterious Gen4 GPU hangs with minimal state changes. Gen4 hardware appears to GPU hang frequently when using Chromium, and also when running 'glmark2 -b ideas'. Most of the error states contain 3DPRIMITIVE commands in quick succession, with very few state packets between them - usually VERTEX_BUFFERS/ELEMENTS and CONSTANT_BUFFER. I trimmed an apitrace of the glmark2 hang down to two draw calls with a glUniformMatrix4fv call between the two. Either draw by itself works fine, but together, they hang the GPU. Removing the glUniform call makes the hangs disappear. In the hardware state, this translates to removing the CONSTANT_BUFFER packet between the two 3DPRIMITIVE packets. Flushing before emitting CONSTANT_BUFFER packets also appears to make the hangs disappear. I observed a slowdown in glxgears by doing it all the time, so I've chosen to only do it when BRW_NEW_BATCH and BRW_NEW_PSP are unset (i.e. we haven't done a CS_URB_STATE change or already flushed the whole pipeline). I'd much rather understand the problem, but at this point, I don't see how we'd ever be able to track it down further. We have no real tools, and the hardware people moved on years ago. I've analyzed 20+ error states and read every scrap of documentation I could find. Bugzilla: <a class="bz_bug_link bz_status_RESOLVED bz_closed" title="RESOLVED FIXED - [gen4] GPU Crash During Google Chrome Operation" href="show_bug.cgi?id=80568">https://bugs.freedesktop.org/show_bug.cgi?id=80568</a> Bugzilla: <a class="bz_bug_link bz_status_RESOLVED bz_closed" title="RESOLVED FIXED - [gen4] GPU hang in glmark-es2" href="show_bug.cgi?id=85367">https://bugs.freedesktop.org/show_bug.cgi?id=85367</a> Signed-off-by: Kenneth Graunke <<a href="mailto:kenneth@whitecape.org">kenneth@whitecape.org</a>> Acked-by: Matt Turner <<a href="mailto:mattst88@gmail.com">mattst88@gmail.com</a>> Cc: "10.4 10.3" <<a href="mailto:mesa-stable@lists.freedesktop.org">mesa-stable@lists.freedesktop.org</a>> It's in git, and backports are in Mesa 10.4.x for x > 3. What version of Mesa do you have?</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>