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    <body><span class="vcard"><a class="email" href="mailto:chris@chris-wilson.co.uk" title="Chris Wilson <chris@chris-wilson.co.uk>"> <span class="fn">Chris Wilson</span></a>
</span> changed
              <a class="bz_bug_link 
          bz_status_RESOLVED  bz_closed"
   title="RESOLVED FIXED - [SKL] sporadic "missed interrupts""
   href="https://bugs.freedesktop.org/show_bug.cgi?id=89493">bug 89493</a>
          <br>
             <table border="1" cellspacing="0" cellpadding="8">
          <tr>
            <th>What</th>
            <th>Removed</th>
            <th>Added</th>
          </tr>

         <tr>
           <td style="text-align:right;">Status</td>
           <td>REOPENED
           </td>
           <td>RESOLVED
           </td>
         </tr>

         <tr>
           <td style="text-align:right;">Resolution</td>
           <td>---
           </td>
           <td>FIXED
           </td>
         </tr></table>
      <p>
        <div>
            <b><a class="bz_bug_link 
          bz_status_RESOLVED  bz_closed"
   title="RESOLVED FIXED - [SKL] sporadic "missed interrupts""
   href="https://bugs.freedesktop.org/show_bug.cgi?id=89493#c6">Comment # 6</a>
              on <a class="bz_bug_link 
          bz_status_RESOLVED  bz_closed"
   title="RESOLVED FIXED - [SKL] sporadic "missed interrupts""
   href="https://bugs.freedesktop.org/show_bug.cgi?id=89493">bug 89493</a>
              from <span class="vcard"><a class="email" href="mailto:chris@chris-wilson.co.uk" title="Chris Wilson <chris@chris-wilson.co.uk>"> <span class="fn">Chris Wilson</span></a>
</span></b>
        <pre>commit 7c17d377374ddbcfb7873366559fc4ed8b296e11
Author: Chris Wilson <<a href="mailto:chris@chris-wilson.co.uk">chris@chris-wilson.co.uk</a>>
Date:   Wed Jan 20 15:43:35 2016 +0200

    drm/i915: Use ordered seqno write interrupt generation on gen8+ execlists

    Broadwell and later currently use the same unordered command sequence to
    update the seqno in the HWS status page and then assert the user
    interrupt. We should apply the w/a from legacy (where we do an mmio
    read to delay the seqno read after the interrupt), but this is not
    enough to enforce coherent seqno visibilty on Skylake. Rather than
    search for the proper post-interrupt seqno barrier, use a strongly
    ordered command sequence to write the seqno, then assert the user
    interrupt from the ring.

    v2: Move around the wa tail dwords to avoid adding duplicate code.

    v3: Add references, comments on workarounds and bit5 check.

    References: <a class="bz_bug_link 
          bz_status_RESOLVED  bz_closed"
   title="RESOLVED FIXED - [BAT SKL BDW] missed interrupt in gem_storedw_loop/basic-render with *ERROR* Hangcheck timer elapsed..."
   href="show_bug.cgi?id=93693">https://bugs.freedesktop.org/show_bug.cgi?id=93693</a>
    Testcase: igt/gem_ring_sync_loop #skl
    Signed-off-by: Chris Wilson <<a href="mailto:chris@chris-wilson.co.uk">chris@chris-wilson.co.uk</a>>
    Cc: Mika Kuoppala <<a href="mailto:mika.kuoppala@intel.com">mika.kuoppala@intel.com</a>>
    Reviewed-by: Mika Kuoppala <<a href="mailto:mika.kuoppala@intel.com">mika.kuoppala@intel.com</a>>
    Link:
<a href="http://patchwork.freedesktop.org/patch/msgid/1453297415-17793-1-git-send-email-mika.kuoppala@intel.com">http://patchwork.freedesktop.org/patch/msgid/1453297415-17793-1-git-send-email-mika.kuoppala@intel.com</a></pre>
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