<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_ASSIGNED " title="ASSIGNED --- - [sna gen4] corrupt rendering (including wrong rendering of characters and flickering on redraw)" href="https://bugs.freedesktop.org/show_bug.cgi?id=55500#c137">Comment # 137</a> on <a class="bz_bug_link bz_status_ASSIGNED " title="ASSIGNED --- - [sna gen4] corrupt rendering (including wrong rendering of characters and flickering on redraw)" href="https://bugs.freedesktop.org/show_bug.cgi?id=55500">bug 55500</a> from <a class="email" href="mailto:zdenek.kabelac@gmail.com" title="Zdenek Kabelac <zdenek.kabelac@gmail.com>"> Zdenek Kabelac</a> <pre>(In reply to <a href="show_bug.cgi?id=55500#c136">comment #136</a>) > The issue that the VUE (which is a memory slot used by the GPU for a vertex > entry) are reused by a second thread before the first thread is complete, > causing the first thread to generate invalid texture coordinates and corrupt > rendering. That is a hardware read-write hazard bug (or at least I have not > found any controls in the EU state to prevent it). I don't think it's that easy to explain - The typical problem in my case is - when I freshly start the Xsession - I do not observe any rendering bug. I need to use this machine for a while, to start to get those errors. So if there would be some 'easy to trigger hardware race' - it should be reproducible all the time. But in my case it seem - the probability increases over the time heavily - maybe with the amount of cached BO segments ? Or maybe it depends on how the memory order is set - i.e. the problem is triggered when certain memory read pattern start to appear ? Since once the issue of flicker starts - it then happens all the time - and then suddenly it disappears for a while again ? So maybe there needs to be prohibited some memory offset/alignment of buffers with vertices ?</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>