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      <base href="https://bugs.freedesktop.org/" />
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    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - [HSW] WARNING: plane A assertion failure, should be disabled but not"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=91429">91429</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>[HSW] WARNING: plane A assertion failure, should be disabled but not
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>DRI
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>XOrg git
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>x86-64 (AMD64)
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>Linux (All)
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>normal
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>medium
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>DRM/Intel
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>intel-gfx-bugs@lists.freedesktop.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>andreas.reis@gmail.com
          </td>
        </tr>

        <tr>
          <th>QA Contact</th>
          <td>intel-gfx-bugs@lists.freedesktop.org
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>intel-gfx-bugs@lists.freedesktop.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Created <span class=""><a href="attachment.cgi?id=117296" name="attach_117296" title="dmesg">attachment 117296</a> <a href="attachment.cgi?id=117296&action=edit" title="dmesg">[details]</a></span>
dmesg

Happens only on my 4770 desktop (one HDMI monitor), on my 4200U laptop it does
not occur.

IIRC it happened since one of Maarten Lankhorst's commits for atomic modeset.
In any case, journalctl lists it first on Jul 16 (I don't compile daily).

No apparent consequences. Driver module is compiled-in.

Originally the error was listed trice, now it's somehow only twice.

[    0.944544] WARNING: CPU: 0 PID: 61 at
drivers/gpu/drm/i915/intel_display.c:1374 assert_planes_disabled+0xe5/0x140()
[    0.944545] plane A assertion failure, should be disabled but not
[    0.944545] Modules linked in:
[    0.944546] CPU: 0 PID: 61 Comm: kworker/0:1 Not tainted 4.2.0-1-cu #1
[    0.944547] Hardware name: Gigabyte Technology Co., Ltd. G1.Sniper
M5/G1.Sniper M5, BIOS T01 02/03/2015
[    0.944549] Workqueue: events output_poll_execute
[    0.944550]  0000000000000000 000000008ed35dd8 ffff88041c0a39e8
ffffffff8193ba5a
[    0.944551]  0000000000000000 ffff88041c0a3a40 ffff88041c0a3a28
ffffffff810e5366
[    0.944552]  0000000100000000 ffff88041b6a0000 0000000000000000
0000000000000000
[    0.944552] Call Trace:
[    0.944555]  [<ffffffff8193ba5a>] dump_stack+0x4c/0x6e
[    0.944557]  [<ffffffff810e5366>] warn_slowpath_common+0x86/0xc0
[    0.944557]  [<ffffffff810e53f5>] warn_slowpath_fmt+0x55/0x70
[    0.944559]  [<ffffffff8161a0c5>] assert_planes_disabled+0xe5/0x140
[    0.944560]  [<ffffffff816243eb>] intel_disable_pipe+0x4b/0x2a0
[    0.944561]  [<ffffffff816246ca>] haswell_crtc_disable+0x8a/0x2d0
[    0.944562]  [<ffffffff81634c86>] intel_atomic_commit+0x116/0x800
[    0.944564]  [<ffffffff815b706d>] ?
drm_atomic_get_connector_state+0x4d/0x110
[    0.944565]  [<ffffffff815b6b97>] drm_atomic_commit+0x37/0x60
[    0.944566]  [<ffffffff81592da7>] drm_atomic_helper_set_config+0x1c7/0x430
[    0.944567]  [<ffffffff815a5a76>] drm_mode_set_config_internal+0x66/0x100
[    0.944569]  [<ffffffff81594d82>] restore_fbdev_mode+0xc2/0xf0
[    0.944570]  [<ffffffff81596c69>]
drm_fb_helper_restore_fbdev_mode_unlocked+0x29/0x70
[    0.944571]  [<ffffffff81596cd2>] drm_fb_helper_set_par+0x22/0x40
[    0.944572]  [<ffffffff81596bfa>] drm_fb_helper_hotplug_event+0xca/0x110
[    0.944574]  [<ffffffff81643e3e>] intel_fbdev_output_poll_changed+0x1e/0x20
[    0.944575]  [<ffffffff8158b31b>] drm_kms_helper_hotplug_event+0x2b/0x40
[    0.944575]  [<ffffffff8158b516>] output_poll_execute+0x186/0x1a0
[    0.944577]  [<ffffffff810fcc5e>] process_one_work+0x14e/0x440
[    0.944578]  [<ffffffff810fcf98>] worker_thread+0x48/0x4a0
[    0.944579]  [<ffffffff810fcf50>] ? process_one_work+0x440/0x440
[    0.944580]  [<ffffffff810fcf50>] ? process_one_work+0x440/0x440
[    0.944581]  [<ffffffff81102838>] kthread+0xd8/0xf0
[    0.944582]  [<ffffffff81102760>] ? kthread_worker_fn+0x170/0x170
[    0.944583]  [<ffffffff8194279f>] ret_from_fork+0x3f/0x70
[    0.944584]  [<ffffffff81102760>] ? kthread_worker_fn+0x170/0x170</pre>
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