Hi,

I am getting this during hibernate/resume with current Linus' head (5f738967e89584f99c6a11c6bf09b16c50b6a03e).

====================================================== [ INFO: possible circular locking dependency detected ] 3.8.0-rc2-00038-ge93d369 #178 Not tainted ------------------------------------------------------- s2disk/3024 is trying to acquire lock: ((fb_notifier_list).rwsem){++++.+}, at: [<ffffffff8107791a>] __blocking_notifier_call_chain+0x5a/0xd0

but task is already holding lock: (console_lock){+.+.+.}, at: [<ffffffff81339865>] do_fb_ioctl+0x455/0x590

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (console_lock){+.+.+.}: [<ffffffff810b1c22>] validate_chain+0x632/0x720 [<ffffffff810b2069>] __lock_acquire+0x359/0x580 [<ffffffff810b23b1>] lock_acquire+0x121/0x190 [<ffffffff810478df>] console_lock+0x6f/0x80 [<ffffffff813b4a5d>] register_con_driver+0x5d/0x160 [<ffffffff813b6c7d>] take_over_console+0x2d/0x70 [<ffffffff81346e33>] fbcon_takeover+0x63/0xc0 [<ffffffff81347b05>] fbcon_fb_registered+0xc5/0x170 [<ffffffff81347d88>] fbcon_event_notify+0x1d8/0x690 [<ffffffff815a83b3>] notifier_call_chain+0x93/0x140 [<ffffffff81077931>] __blocking_notifier_call_chain+0x71/0xd0 [<ffffffff810779a1>] blocking_notifier_call_chain+0x11/0x20 [<ffffffff81337836>] fb_notifier_call_chain+0x16/0x20 [<ffffffff81338ed1>] do_register_framebuffer+0x221/0x2e0 [<ffffffff81338fb2>] register_framebuffer+0x22/0x40 [<ffffffffa00e538c>] drm_fb_helper_single_fb_probe+0x2bc/0x300 [drm_kms_helper] [<ffffffffa00e5462>] drm_fb_helper_initial_config+0x92/0xd0 [drm_kms_helper] [<ffffffffa014528b>] intel_fbdev_init+0x8b/0xc0 [i915] [<ffffffffa00f8d63>] i915_load_modeset_init+0x113/0x1d0 [i915] [<ffffffffa00fad25>] i915_driver_load+0x5e5/0x940 [i915] [<ffffffffa009cb46>] drm_get_pci_dev+0x196/0x2a0 [drm] [<ffffffffa00f590d>] i915_pci_probe+0x3d/0x90 [i915] [<ffffffff81323359>] local_pci_probe+0x49/0x80 [<ffffffff81323469>] __pci_device_probe+0xd9/0xe0 [<ffffffff81324686>] pci_device_probe+0x36/0x60 [<ffffffff813dbce9>] really_probe+0x79/0x350 [<ffffffff813dc014>] driver_probe_device+0x54/0xa0 [<ffffffff813dc0fb>] __driver_attach+0x9b/0xa0 [<ffffffff813d9ea8>] bus_for_each_dev+0x68/0x90 [<ffffffff813db99c>] driver_attach+0x1c/0x20 [<ffffffff813db3b8>] bus_add_driver+0x1d8/0x290 [<ffffffff813dc683>] driver_register+0x63/0x150 [<ffffffff81324792>] __pci_register_driver+0x62/0x70 [<ffffffffa009cd5c>] drm_pci_init+0x10c/0x120 [drm] [<ffffffffa018c05d>] tpm_bios_measurements_start+0x5d/0xa0 [tpm_bios] [<ffffffff810001dd>] do_one_initcall+0x3d/0x180 [<ffffffff810bdbfb>] do_init_module+0x6b/0x1d0 [<ffffffff810c089e>] load_module+0x6fe/0x7e0 [<ffffffff810c0aeb>] sys_init_module+0x9b/0xc0 [<ffffffff815ad229>] system_call_fastpath+0x16/0x1b

-> #0 ((fb_notifier_list).rwsem){++++.+}: [<ffffffff810b158e>] check_prev_add+0x3de/0x440 [<ffffffff810b1c22>] validate_chain+0x632/0x720 [<ffffffff810b2069>] __lock_acquire+0x359/0x580 [<ffffffff810b23b1>] lock_acquire+0x121/0x190 [<ffffffff815a13a2>] down_read+0x42/0x60 [<ffffffff8107791a>] __blocking_notifier_call_chain+0x5a/0xd0 [<ffffffff810779a1>] blocking_notifier_call_chain+0x11/0x20 [<ffffffff81337836>] fb_notifier_call_chain+0x16/0x20 [<ffffffff81339262>] fb_set_var+0x232/0x3e0 [<ffffffff81339878>] do_fb_ioctl+0x468/0x590 [<ffffffff81339c6d>] fb_ioctl+0x3d/0x50 [<ffffffff811a460d>] do_vfs_ioctl+0x9d/0x350 [<ffffffff811a4951>] sys_ioctl+0x91/0xb0 [<ffffffff815ad229>] system_call_fastpath+0x16/0x1b

other info that might help us debug this:

Possible unsafe locking scenario:

CPU0 CPU1 ---- ---- lock(console_lock); lock((fb_notifier_list).rwsem); lock(console_lock); lock((fb_notifier_list).rwsem);

*** DEADLOCK ***

2 locks held by s2disk/3024: #0: (&fb_info->lock){+.+.+.}, at: [<ffffffff81337dd2>] lock_fb_info+0x22/0x50 #1: (console_lock){+.+.+.}, at: [<ffffffff81339865>] do_fb_ioctl+0x455/0x590

stack backtrace: Pid: 3024, comm: s2disk Not tainted 3.8.0-rc2-00038-ge93d369 #178 Call Trace: [<ffffffff810af6cf>] print_circular_bug+0x10f/0x120 [<ffffffff810b158e>] check_prev_add+0x3de/0x440 [<ffffffff810b1c22>] validate_chain+0x632/0x720 [<ffffffff810b2069>] __lock_acquire+0x359/0x580 [<ffffffff810b0f7d>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff810b23b1>] lock_acquire+0x121/0x190 [<ffffffff8107791a>] ? __blocking_notifier_call_chain+0x5a/0xd0 [<ffffffff815a13a2>] down_read+0x42/0x60 [<ffffffff8107791a>] ? __blocking_notifier_call_chain+0x5a/0xd0 [<ffffffff8107791a>] __blocking_notifier_call_chain+0x5a/0xd0 [<ffffffff810779a1>] blocking_notifier_call_chain+0x11/0x20 [<ffffffff81337836>] fb_notifier_call_chain+0x16/0x20 [<ffffffff81339262>] fb_set_var+0x232/0x3e0 [<ffffffff81339865>] ? do_fb_ioctl+0x455/0x590 [<ffffffff810b0f7d>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff81339878>] do_fb_ioctl+0x468/0x590 [<ffffffff810b2069>] ? __lock_acquire+0x359/0x580 [<ffffffff811b1b6c>] ? fget_light+0xbc/0x480 [<ffffffff81339c6d>] fb_ioctl+0x3d/0x50 [<ffffffff811a460d>] do_vfs_ioctl+0x9d/0x350 [<ffffffff811b1ae7>] ? fget_light+0x37/0x480 [<ffffffff811a4951>] sys_ioctl+0x91/0xb0 [<ffffffff815ad229>] system_call_fastpath+0x16/0x1b