<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW --- - Severe misrendering in Left 4 Dead 2" href="https://bugs.freedesktop.org/show_bug.cgi?id=64323#c29">Comment # 29</a> on <a class="bz_bug_link bz_status_NEW " title="NEW --- - Severe misrendering in Left 4 Dead 2" href="https://bugs.freedesktop.org/show_bug.cgi?id=64323">bug 64323</a> from <a class="email" href="mailto:imirkin@alum.mit.edu" title="Ilia Mirkin <imirkin@alum.mit.edu>"> Ilia Mirkin</a> <pre>The wait is correct and always needed. I believe that the last patch is actually incorrect. I've added a whole bunch of comments to that function which reflect my understanding of how it works. It appears to be correct. I think what's happening is that (a) inline write to GART. no staging, just returns the buffer's memory (b) something happens (c) inline write to GART. at this point, the GPU is now reading the buffer. so it has to do the whole staging dance to schedule the write to be done by the GPU. (d) render happens, and has to wait for that second inline write to complete. I have yet to figure out what (b) is -- I did some printf-debugging and I'm fairly sure about parts (a) and (c). But by the time (c) happened, the buffer's status had the GPU_READING bit set, and it had a ->fence set on it. I made yet-another attempt at improving this by forcing the second inline write to wait for the gpu to stop reading and then do the GART copy directly, but that didn't seem to help.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>