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            <b><a class="bz_bug_link 
          bz_status_REOPENED "
   title="REOPENED - brw_meta_fast_clear (brw=brw@entry=0x7fffd4097a08, fb=fb@entry=0x7fffd40fa900, buffers=buffers@entry=2, partial_clear=partial_clear@entry=false)"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=86281#c14">Comment # 14</a>
              on <a class="bz_bug_link 
          bz_status_REOPENED "
   title="REOPENED - brw_meta_fast_clear (brw=brw@entry=0x7fffd4097a08, fb=fb@entry=0x7fffd40fa900, buffers=buffers@entry=2, partial_clear=partial_clear@entry=false)"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=86281">bug 86281</a>
              from <span class="vcard"><a class="email" href="mailto:sandsmark@samfundet.no" title="Martin Sandsmark <sandsmark@samfundet.no>"> <span class="fn">Martin Sandsmark</span></a>
</span></b>
        <pre>I can reproduce it here on ArchLinux with broadwell. Googling a bit shows it
happening for people using xbmc, gnome shell or plasma on various distros.

I just hacked in a null check to stop the crashing for now (hard to work when
the desktop shell keeps crashing):

diff --git a/src/mesa/drivers/dri/i965/brw_meta_fast_clear.c
b/src/mesa/drivers/dri/i965/brw_meta_fast_clear.c
index 5b8191c..f0e5e77 100644
--- a/src/mesa/drivers/dri/i965/brw_meta_fast_clear.c
+++ b/src/mesa/drivers/dri/i965/brw_meta_fast_clear.c
@@ -442,6 +442,10 @@ brw_meta_fast_clear(struct brw_context *brw, struct
gl_framebuffer *fb,
       if (rb == NULL)
          continue;

+      // For some reason this render buffer can lack a mipmap tree
+      if (irb->mt == NULL)
+          continue;
+
       clear_type = FAST_CLEAR;

       /* We don't have fast clear until gen7. */</pre>
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