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<b><a class="bz_bug_link
bz_status_ASSIGNED "
title="ASSIGNED - [SKL bisected] texsubimage pbo intermittent failures"
href="https://bugs.freedesktop.org/show_bug.cgi?id=91926#c39">Comment # 39</a>
on <a class="bz_bug_link
bz_status_ASSIGNED "
title="ASSIGNED - [SKL bisected] texsubimage pbo intermittent failures"
href="https://bugs.freedesktop.org/show_bug.cgi?id=91926">bug 91926</a>
from <span class="vcard"><a class="email" href="mailto:topi.pohjolainen@intel.com" title="Topi Pohjolainen <topi.pohjolainen@intel.com>"> <span class="fn">Topi Pohjolainen</span></a>
</span></b>
<pre>In workarounds I found the following:
"For Gen6 and Gen7, any time a pipeline flush is used it needs to be
followed by eight (8) separate storeDW commands. This is done as a
workaround to a known issue where the pipeline flush does not push all
cycles to the "GO" point. The storeDWs will not accomplish this process
but will create enough stall time to ensure all cycles are at GO prior
to execution of the next buffer or part of the buffer. This is required
for producer/consumer model."
I don't exactly know to what "storeDW" refers here and I added in
brw_emit_mi_flush() after the flush:
for (unsigned i = 0; i < 8; ++i)
brw_emit_pipe_control_write(brw, PIPE_CONTROL_WRITE_IMMEDIATE,
brw->workaround_bo, 0, 0, 0);
(which writes in fact 8 times qwords).
This at least doesn't make any difference either on IVB or SKL.</pre>
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