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<b><a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - Recent change makes Xorg hangs"
href="https://bugs.freedesktop.org/show_bug.cgi?id=94685#c9">Comment # 9</a>
on <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - Recent change makes Xorg hangs"
href="https://bugs.freedesktop.org/show_bug.cgi?id=94685">bug 94685</a>
from <span class="vcard"><a class="email" href="mailto:joakim.tjernlund@infinera.com" title="Joakim Tjernlund <joakim.tjernlund@infinera.com>"> <span class="fn">Joakim Tjernlund</span></a>
</span></b>
<pre>(In reply to Chris Wilson from <a href="show_bug.cgi?id=94685#c4">comment #4</a>)
<span class="quote">> So I think it was just because the test should be for 31bits and not 32bits
> (or at least you hit the same bug I just reproduced in a testcase here):
>
> commit c186d4dda3b62b73af3caf2883a9cedfd97e3b45
> Author: Chris Wilson <<a href="mailto:chris@chris-wilson.co.uk">chris@chris-wilson.co.uk</a>>
> Date: Thu Mar 24 18:22:20 2016 +0000
>
> sna/present: Restrict vblank.sequence range to 31bits
>
> The kernel checks for past vblanks using an int32_t comparison, so we
> can only program up to 31bits into the future (and similarly programing
> a timer that large would also overflow).
>
> References: <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - Recent change makes Xorg hangs"
href="show_bug.cgi?id=94685">https://bugs.freedesktop.org/show_bug.cgi?id=94685</a>
> Signed-off-by: Chris Wilson <<a href="mailto:chris@chris-wilson.co.uk">chris@chris-wilson.co.uk</a>>
>
> The debug log would still be very helpful, thanks.</span >
+ if (warn_unless(msc - swap->msc < 1ull<<31))
Are you not allowed to used the lower bits here(as in 0x7ffffff)?</pre>
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