Hi,<div><br></div><div>I&#39;ve been seeing these lately, Xorg version is 1.9.0 with latest git kernel.</div><div><br></div><div><div>=======================================================                                                                                                                    </div>
<div>[ INFO: possible circular locking dependency detected ]                                                                                                                    </div><div>2.6.37-rc1-uwe1+ #4                                                                                                                                                        </div>
<div>-------------------------------------------------------                                                                                                                    </div><div>Xorg/1401 is trying to acquire lock:                                                                                                                                       </div>
<div> (&amp;mm-&gt;mmap_sem){++++++}, at: [&lt;c01e4ddb&gt;] might_fault+0x4b/0xa0                                                                                                           </div><div>                                                                                                                                                                           </div>
<div>but task is already holding lock:                                                                                                                                          </div><div> (&amp;dev-&gt;struct_mutex){+.+.+.}, at: [&lt;f869c3ac&gt;] i915_mutex_lock_interruptible+0x3c/0x60 [i915]                                                                             </div>
<div>                                                                                                                                                                           </div><div>which lock already depends on the new lock.                                                                                                                                </div>
<div>                                                                                                                                                                           </div><div>                                                                                                                                                                           </div>
<div>the existing dependency chain (in reverse order) is:                                                                                                                       </div><div>                                                                                                                                                                           </div>
<div>-&gt; #1 (&amp;dev-&gt;struct_mutex){+.+.+.}:                                                                                                                                        </div><div>       [&lt;c01738ec&gt;] lock_acquire+0x7c/0x120                                                                                                                                </div>
<div>       [&lt;c04d3560&gt;] mutex_lock_nested+0x60/0x330                                                                                                                           </div><div>       [&lt;f810c7aa&gt;] drm_gem_mmap+0x3a/0x140 [drm]                                                                                                                          </div>
<div>       [&lt;c01ec202&gt;] mmap_region+0x2e2/0x430                                                                                                                                </div><div>       [&lt;c01ec59f&gt;] do_mmap_pgoff+0x24f/0x2f0                                                                                                                              </div>
<div>       [&lt;c01ec6bb&gt;] sys_mmap_pgoff+0x7b/0x110                                                                                                                              </div><div>       [&lt;c0102f97&gt;] sysenter_do_call+0x12/0x36                                                                                                                             </div>
<div>                                                                                                                                                                           </div><div>-&gt; #0 (&amp;mm-&gt;mmap_sem){++++++}:                                                                                                                                             </div>
<div>       [&lt;c0173549&gt;] __lock_acquire+0x14a9/0x17d0                                                                                                                           </div><div>       [&lt;c01738ec&gt;] lock_acquire+0x7c/0x120                                                                                                                                </div>
<div>       [&lt;c01e4e0c&gt;] might_fault+0x7c/0xa0                                                                                                                                  </div><div>       [&lt;c032dfad&gt;] _copy_from_user+0x3d/0x130                                                                                                                             </div>
<div>       [&lt;f869cdec&gt;] i915_gem_pwrite_ioctl+0x18c/0xb20 [i915]                                                                                                               </div><div>       [&lt;f810afd2&gt;] drm_ioctl+0x1e2/0x440 [drm]                                                                                                                            </div>
<div>       [&lt;c0216dcd&gt;] do_vfs_ioctl+0x9d/0x6c0                                                                                                                                </div><div>       [&lt;c0217457&gt;] sys_ioctl+0x67/0x80                                                                                                                                    </div>
<div>       [&lt;c0102f97&gt;] sysenter_do_call+0x12/0x36                                                                                                                             </div><div>                                                                                                                                                                           </div>
<div>other info that might help us debug this:                                                                                                                                  </div><div>                                                                                                                                                                           </div>
<div>1 lock held by Xorg/1401:                                                                                                                                                  </div><div> #0:  (&amp;dev-&gt;struct_mutex){+.+.+.}, at: [&lt;f869c3ac&gt;] i915_mutex_lock_interruptible+0x3c/0x60 [i915]</div>
</div><div><div>                                                                                                                                                                         </div><div>stack backtrace:                                                                                                                                                           </div>
<div>Pid: 1401, comm: Xorg Not tainted 2.6.37-rc1-uwe1+ #4                                                                                                                      </div><div>Call Trace:                                                                                                                                                                </div>
<div> [&lt;c04d12de&gt;] ? printk+0x1d/0x1f                                                                                                                                           </div><div> [&lt;c01714f2&gt;] print_circular_bug+0xc2/0xd0                                                                                                                                 </div>
<div> [&lt;c0173549&gt;] __lock_acquire+0x14a9/0x17d0                                                                                                                                 </div><div> [&lt;c04d82c9&gt;] ? sub_preempt_count+0x9/0x50                                                                                                                                 </div>
<div> [&lt;c01738ec&gt;] lock_acquire+0x7c/0x120                                                                                                                                      </div><div> [&lt;c01e4ddb&gt;] ? might_fault+0x4b/0xa0                                                                                                                                      </div>
<div> [&lt;c01e4e0c&gt;] might_fault+0x7c/0xa0                                                                                                                                        </div><div> [&lt;c01e4ddb&gt;] ? might_fault+0x4b/0xa0                                                                                                                                      </div>
<div> [&lt;c032dfad&gt;] _copy_from_user+0x3d/0x130                                                                                                                                   </div><div> [&lt;f869cdec&gt;] i915_gem_pwrite_ioctl+0x18c/0xb20 [i915]                                                                                                                     </div>
<div> [&lt;c01e4ddb&gt;] ? might_fault+0x4b/0xa0                                                                                                                                      </div><div> [&lt;f810afd2&gt;] drm_ioctl+0x1e2/0x440 [drm]                                                                                                                                  </div>
<div> [&lt;f869cc60&gt;] ? i915_gem_pwrite_ioctl+0x0/0xb20 [i915]                                                                                                                     </div><div> [&lt;c02f36d3&gt;] ? smk_access+0xb3/0x1f0                                                                                                                                      </div>
<div> [&lt;c02f3914&gt;] ? smk_curacc+0x74/0xa0                                                                                                                                       </div><div> [&lt;f810adf0&gt;] ? drm_ioctl+0x0/0x440 [drm]                                                                                                                                  </div>
<div> [&lt;c0216dcd&gt;] do_vfs_ioctl+0x9d/0x6c0                                                                                                                                      </div><div> [&lt;c0217457&gt;] sys_ioctl+0x67/0x80                                                                                                                                          </div>
<div> [&lt;c0102f97&gt;] sysenter_do_call+0x12/0x36</div></div><div><br></div><div>thanks,</div><div>Uwe</div>