Hi,

I've been seeing these lately, Xorg version is 1.9.0 with latest git kernel.

=======================================================

[ INFO: possible circular locking dependency detected ]

2.6.37-rc1-uwe1+ #4

-------------------------------------------------------

Xorg/1401 is trying to acquire lock:

(&mm->mmap_sem){++++++}, at: [<c01e4ddb>] might_fault+0x4b/0xa0

but task is already holding lock:

(&dev->struct_mutex){+.+.+.}, at: [<f869c3ac>] i915_mutex_lock_interruptible+0x3c/0x60 [i915]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&dev->struct_mutex){+.+.+.}:

[<c01738ec>] lock_acquire+0x7c/0x120

[<c04d3560>] mutex_lock_nested+0x60/0x330

[<f810c7aa>] drm_gem_mmap+0x3a/0x140 [drm]

[<c01ec202>] mmap_region+0x2e2/0x430

[<c01ec59f>] do_mmap_pgoff+0x24f/0x2f0

[<c01ec6bb>] sys_mmap_pgoff+0x7b/0x110

[<c0102f97>] sysenter_do_call+0x12/0x36

-> #0 (&mm->mmap_sem){++++++}:

[<c0173549>] __lock_acquire+0x14a9/0x17d0

[<c01738ec>] lock_acquire+0x7c/0x120

[<c01e4e0c>] might_fault+0x7c/0xa0

[<c032dfad>] _copy_from_user+0x3d/0x130

[<f869cdec>] i915_gem_pwrite_ioctl+0x18c/0xb20 [i915]

[<f810afd2>] drm_ioctl+0x1e2/0x440 [drm]

[<c0216dcd>] do_vfs_ioctl+0x9d/0x6c0

[<c0217457>] sys_ioctl+0x67/0x80

[<c0102f97>] sysenter_do_call+0x12/0x36

other info that might help us debug this:

1 lock held by Xorg/1401:

#0: (&dev->struct_mutex){+.+.+.}, at: [<f869c3ac>] i915_mutex_lock_interruptible+0x3c/0x60 [i915]

stack backtrace:

Pid: 1401, comm: Xorg Not tainted 2.6.37-rc1-uwe1+ #4

Call Trace:

[<c04d12de>] ? printk+0x1d/0x1f

[<c01714f2>] print_circular_bug+0xc2/0xd0

[<c0173549>] __lock_acquire+0x14a9/0x17d0

[<c04d82c9>] ? sub_preempt_count+0x9/0x50

[<c01738ec>] lock_acquire+0x7c/0x120

[<c01e4ddb>] ? might_fault+0x4b/0xa0

[<c01e4e0c>] might_fault+0x7c/0xa0

[<c01e4ddb>] ? might_fault+0x4b/0xa0

[<c032dfad>] _copy_from_user+0x3d/0x130

[<f869cdec>] i915_gem_pwrite_ioctl+0x18c/0xb20 [i915]

[<c01e4ddb>] ? might_fault+0x4b/0xa0

[<f810afd2>] drm_ioctl+0x1e2/0x440 [drm]

[<f869cc60>] ? i915_gem_pwrite_ioctl+0x0/0xb20 [i915]

[<c02f36d3>] ? smk_access+0xb3/0x1f0

[<c02f3914>] ? smk_curacc+0x74/0xa0

[<f810adf0>] ? drm_ioctl+0x0/0x440 [drm]

[<c0216dcd>] do_vfs_ioctl+0x9d/0x6c0

[<c0217457>] sys_ioctl+0x67/0x80

[<c0102f97>] sysenter_do_call+0x12/0x36

thanks, Uwe