<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [regression][hang] Trine1EE hangs GPU after loading screen on Mesa3D-17.3 and later" href="https://bugs.freedesktop.org/show_bug.cgi?id=105670#c6">Comment # 6</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [regression][hang] Trine1EE hangs GPU after loading screen on Mesa3D-17.3 and later" href="https://bugs.freedesktop.org/show_bug.cgi?id=105670">bug 105670</a> from <a class="email" href="mailto:t_arceri@yahoo.com.au" title="Timothy Arceri <t_arceri@yahoo.com.au>"> Timothy Arceri</a> <pre>(In reply to Gert Wollny from <a href="show_bug.cgi?id=105670#c2">comment #2</a>) > I can confirm this on Radeon 6870 HD. > > I was able to track the issue to the series beginning with > > ab23b759f24 glsl: don't drop instructions from unreachable > terminators continue branch > > The first time around I had a few difficulties get the correct patch, it > seems to be either 646621c66da9 or 7a7fb90af75. In any case, yes it is > related to loop unrolling. > > The original TGSI goes like > > BGNLOOP > ISGE TEMP[13].x, TEMP[8].xxxx, IMM[7].yyyy > UIF TEMP[13].xxxx > BRK > ENDIF > ... > ENDLOOP > > and with the series in question applied it is > > BGNLOOP > ISLT TEMP[13].x, TEMP[8].xxxx, IMM[7].yyyy > UIF TEMP[13].xxxx > ... > ENDI > ENDLOOP > > This UIF should have an else path with the BRK to resemble the original > code. > (There are more BRK statements in the LOOP but they are the same in both > versions. > > Regarding bisecting this, after a failure one usually must reboot the > system, otherwise the graphics card is in a bad state. But given the nature > of the bug one should also be able to reproduce the endless loop with > LIBGL_ALWAYS_SOFTWARE=1 thereby not clobbering the hardware. Thanks for tracking down the problem. Do you think you would be able to create a piglit test to reproduce the bug? Or failing that can you copy the full glsl loop an attach it to the bug so that I can attempt to recreate the issue in piglit. Thanks.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>