drm_modeset_lock oops in next

[Tony Lindgren]

Hi,

Looks like current next now oopses at least for omapdrm
when starting X. Reverting commit d20afeb3e2f9 ("Merge
remote-tracking branch 'drm-misc/for-linux-next'") makes
things work again.

Any ideas what might be causing the oops below?

Regards,

Tony

8< --------------------------
Internal error: Oops: 5 [#1] SMP ARM
...
CPU: 1 PID: 1637 Comm: X Not tainted 4.11.0-rc5-next-20170407+ #488
Hardware name: Generic OMAP4 (Flattened Device Tree)
task: ec873180 task.stack: ec8b8000
PC is at __ww_mutex_lock.constprop.0+0x34/0x1054
LR is at lock_is_held_type+0x60/0xa8
pc : [<c0833098>]    lr : [<c0199abc>]    psr: a0000013
               sp : ec8b9d18  ip : 00000002  fp : edb2a800
r10: ec8b9dc0  r9 : edb2c800  r8 : ec88c400
r7 : ec8b9e1c  r6 : bf70f648  r5 : ec8b9dd8  r4 : 00000010
r3 : 00400100  r2 : ec8b9cf8  r1 : ffffffff  r0 : 00000000
Flags: NzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
Control: 10c5387d  Table: ac85c04a  DAC: 00000051
Process X (pid: 1637, stack limit = 0xec8b8218)
...
[<c0833098>] (__ww_mutex_lock.constprop.0) from [<c0834150>] (ww_mutex_lock+0x44/0x54)
[<c0834150>] (ww_mutex_lock) from [<bf70f648>] (drm_modeset_lock+0x60/0x110 [drm])
[<bf70f648>] (drm_modeset_lock [drm]) from [<bf718740>] (drm_mode_cursor_common+0x98/0x1f0 [drm])
[<bf718740>] (drm_mode_cursor_common [drm]) from [<bf718f1c>] (drm_mode_cursor_ioctl+0x58/0x60 [drm])
[<bf718f1c>] (drm_mode_cursor_ioctl [drm]) from [<bf6fe5c8>] (drm_ioctl+0x1d4/0x404 [drm])
[<bf6fe5c8>] (drm_ioctl [drm]) from [<c02d3884>] (do_vfs_ioctl+0x90/0xa54)
[<c02d3884>] (do_vfs_ioctl) from [<c02d42b4>] (SyS_ioctl+0x6c/0x7c)
[<c02d42b4>] (SyS_ioctl) from [<c01077c0>] (ret_fast_syscall+0x0/0x1c)
Code: e58d3018 ebe4cd4e e35a0000 0a000002 (e5943044)