Hi,
I have a Lenovo T410s (Ironlake/Arrandale graphics) that I use docked and connected to an external DP monitor (laptop is closed so the only active display is the DP monitor). With 3.12-rc4 I reproducably hit a deadlock when I undock the laptop -- it seems to be a deadlock on dev->mode_confix.mutext between intel_crtc_wait_for_pending_flips (mutex held because of drm_modeset_lock_all in intel_lid_notify) and drm_mode_getconnector. See below for the kernel logging (there's no logging for more than 2 minutes before the hung task stuff) -- it seems that intel_crtc_wait_for_pending_flips is getting stuck, and then everything else piles up behind it:
[ 241.009121] INFO: task kworker/0:1:70 blocked for more than 120 seconds. [ 241.009131] Tainted: G W 3.12.0-999-generic #201310070425 [ 241.009133] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 241.009137] kworker/0:1 D 0000000000000000 0 70 2 0x00000000 [ 241.009152] Workqueue: kacpi_notify acpi_os_execute_deferred [ 241.009156] ffff88022b2c9ae8 0000000000000046 ffff88022b2c9ab8 000000008e17de71 [ 241.009162] ffff88022b2c9fd8 ffff88022b2c9fd8 ffff88022b2c9fd8 00000000000144c0 [ 241.009167] ffffffff81c144a0 ffff88022b290000 0000000000000286 ffff88022ae70000 [ 241.009173] Call Trace: [ 241.009186] [<ffffffff81753619>] schedule+0x29/0x70 [ 241.009247] [<ffffffffa011eb9d>] intel_crtc_wait_for_pending_flips+0x8d/0x120 [i915] [ 241.009257] [<ffffffff8108cc30>] ? add_wait_queue+0x60/0x60 [ 241.009289] [<ffffffffa0127baf>] ironlake_crtc_disable+0x7f/0x2a0 [i915] [ 241.009318] [<ffffffffa012a0f6>] intel_crtc_update_dpms+0x76/0xb0 [i915] [ 241.009347] [<ffffffffa012d8e5>] intel_sanitize_crtc+0xd5/0x370 [i915] [ 241.009377] [<ffffffffa012e1ed>] intel_modeset_setup_hw_state+0x17d/0x380 [i915] [ 241.009407] [<ffffffffa01307a1>] intel_lid_notify+0xc1/0x100 [i915] [ 241.009412] [<ffffffff817596ad>] notifier_call_chain+0x4d/0x70 [ 241.009419] [<ffffffff81091ea8>] __blocking_notifier_call_chain+0x58/0x80 [ 241.009424] [<ffffffff81091ee6>] blocking_notifier_call_chain+0x16/0x20 [ 241.009431] [<ffffffff8142b15b>] acpi_lid_send_state+0x86/0xaf [ 241.009436] [<ffffffff8142b1e1>] acpi_button_notify+0x3b/0xa2 [ 241.009442] [<ffffffff814032f1>] acpi_device_notify+0x19/0x1b [ 241.009448] [<ffffffff814131cd>] acpi_ev_notify_dispatch+0x41/0x5c [ 241.009453] [<ffffffff813ff59e>] acpi_os_execute_deferred+0x25/0x32 [ 241.009458] [<ffffffff81083ccf>] process_one_work+0x17f/0x4d0 [ 241.009463] [<ffffffff81084f0b>] worker_thread+0x11b/0x3d0 [ 241.009468] [<ffffffff81084df0>] ? manage_workers.isra.20+0x1b0/0x1b0 [ 241.009473] [<ffffffff8108c0d0>] kthread+0xc0/0xd0 [ 241.009479] [<ffffffff8108c010>] ? flush_kthread_worker+0xb0/0xb0 [ 241.009484] [<ffffffff8175dfbc>] ret_from_fork+0x7c/0xb0 [ 241.009489] [<ffffffff8108c010>] ? flush_kthread_worker+0xb0/0xb0 [ 241.009525] INFO: task Xorg:1436 blocked for more than 120 seconds. [ 241.009528] Tainted: G W 3.12.0-999-generic #201310070425 [ 241.009531] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 241.009533] Xorg D 0000000000000000 0 1436 1410 0x00400004 [ 241.009538] ffff88022ca1bc48 0000000000000082 ffff88022ca1bc18 ffffffff811a31a1 [ 241.009543] ffff88022ca1bfd8 ffff88022ca1bfd8 ffff88022ca1bfd8 00000000000144c0 [ 241.009549] ffff880230198000 ffff8800b06546e0 ffff88022ca1bc28 ffff8800363b8330 [ 241.009554] Call Trace: [ 241.009562] [<ffffffff811a31a1>] ? kmem_cache_free+0x121/0x180 [ 241.009568] [<ffffffff81753619>] schedule+0x29/0x70 [ 241.009574] [<ffffffff8175394e>] schedule_preempt_disabled+0xe/0x10 [ 241.009580] [<ffffffff817518c4>] __mutex_lock_slowpath+0x114/0x1b0 [ 241.009585] [<ffffffff81751983>] mutex_lock+0x23/0x40 [ 241.009613] [<ffffffffa004e582>] drm_mode_getconnector+0xb2/0x430 [drm] [ 241.009633] [<ffffffffa003ef1a>] drm_ioctl+0x4fa/0x620 [drm] [ 241.009656] [<ffffffffa004e4d0>] ? drm_mode_getcrtc+0xe0/0xe0 [drm] [ 241.009663] [<ffffffff811cedda>] do_vfs_ioctl+0x7a/0x2e0 [ 241.009668] [<ffffffff811bcc01>] ? vfs_read+0x111/0x180 [ 241.009673] [<ffffffff811cf0d1>] SyS_ioctl+0x91/0xb0 [ 241.009678] [<ffffffff811bce40>] ? SyS_read+0x70/0xa0 [ 241.009683] [<ffffffff8175e06d>] system_call_fastpath+0x1a/0x1f
Detailed lspci info for my laptop:
00:00.0 Host bridge [0600]: Intel Corporation Core Processor DRAM Controller [8086:0044] (rev 02) 00:02.0 VGA compatible controller [0300]: Intel Corporation Core Processor Integrated Graphics Controller [8086:0046] (rev 02) 00:16.0 Communication controller [0780]: Intel Corporation 5 Series/3400 Series Chipset HECI Controller [8086:3b64] (rev 06) 00:19.0 Ethernet controller [0200]: Intel Corporation 82577LM Gigabit Network Connection [8086:10ea] (rev 06) 00:1a.0 USB controller [0c03]: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller [8086:3b3c] (rev 06) 00:1b.0 Audio device [0403]: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio [8086:3b57] (rev 06) 00:1c.0 PCI bridge [0604]: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 1 [8086:3b42] (rev 06) 00:1c.1 PCI bridge [0604]: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 2 [8086:3b44] (rev 06) 00:1c.3 PCI bridge [0604]: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 4 [8086:3b48] (rev 06) 00:1d.0 USB controller [0c03]: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller [8086:3b34] (rev 06) 00:1e.0 PCI bridge [0604]: Intel Corporation 82801 Mobile PCI Bridge [8086:2448] (rev a6) 00:1f.0 ISA bridge [0601]: Intel Corporation 5 Series/3400 Series Chipset LPC Interface Controller [8086:3b0f] (rev 06) 00:1f.2 SATA controller [0106]: Intel Corporation 5 Series/3400 Series Chipset 6 port SATA AHCI Controller [8086:3b2f] (rev 06) 00:1f.3 SMBus [0c05]: Intel Corporation 5 Series/3400 Series Chipset SMBus Controller [8086:3b30] (rev 06) 00:1f.6 Signal processing controller [1180]: Intel Corporation 5 Series/3400 Series Chipset Thermal Subsystem [8086:3b32] (rev 06) 03:00.0 Network controller [0280]: Intel Corporation Centrino Wireless-N 1000 [Condor Peak] [8086:0084] ff:00.0 Host bridge [0600]: Intel Corporation Core Processor QuickPath Architecture Generic Non-core Registers [8086:2c62] (rev 02) ff:00.1 Host bridge [0600]: Intel Corporation Core Processor QuickPath Architecture System Address Decoder [8086:2d01] (rev 02) ff:02.0 Host bridge [0600]: Intel Corporation Core Processor QPI Link 0 [8086:2d10] (rev 02) ff:02.1 Host bridge [0600]: Intel Corporation Core Processor QPI Physical 0 [8086:2d11] (rev 02) ff:02.2 Host bridge [0600]: Intel Corporation Core Processor Reserved [8086:2d12] (rev 02) ff:02.3 Host bridge [0600]: Intel Corporation Core Processor Reserved [8086:2d13] (rev 02)
Please let me know if there is any way I can help debug this further.
Thanks! Roland