467221bc60
intel_engine_wakeup() is called by nop_request_submit() which is installed to handle third party fences completed from within irq context. As such, it needs the full irqsave/irqrestore and not the partial spin_irq_lock handling. [18942.714467] ================================= [18942.719076] [ INFO: inconsistent lock state ] [18942.723522] 4.11.0-rc2-CI-CI_DRM_2368+ #1 Tainted: G U W [18942.729970] --------------------------------- [18942.734466] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. [18942.740594] gem_eio/1275 [HC0[0]:SC0[0]:HE1:SE1] takes: [18942.745932] (&(&fence->lock)->rlock){+.?...}, at: [<ffffffff815ec100>] dma_fence_signal+0x100/0x 230 [18942.755331] {IN-SOFTIRQ-W} state was registered at: [18942.760356] __lock_acquire+0x5d0/0x1bb0 [18942.764444] lock_acquire+0xc9/0x220 [18942.768196] _raw_spin_lock_irqsave+0x41/0x60 [18942.772747] dma_fence_signal+0x100/0x230 [18942.776927] vgem_fence_timeout+0x9/0x10 [vgem] [18942.781701] call_timer_fn+0x92/0x380 [18942.785557] expire_timers+0x150/0x1f0 [18942.789491] run_timer_softirq+0x7c/0x160 [18942.793705] __do_softirq+0x116/0x4c0 [18942.797560] irq_exit+0xa9/0xc0 [18942.800873] smp_apic_timer_interrupt+0x38/0x50 [18942.805611] apic_timer_interrupt+0x90/0xa0 [18942.810008] cpuidle_enter_state+0x135/0x380 [18942.814503] cpuidle_enter+0x12/0x20 [18942.818250] call_cpuidle+0x1e/0x40 [18942.821906] do_idle+0x17e/0x1f0 [18942.825333] cpu_startup_entry+0x18/0x20 [18942.829463] rest_init+0x127/0x130 [18942.833025] start_kernel+0x3f1/0x3fe [18942.836908] x86_64_start_reservations+0x2a/0x2c [18942.841733] x86_64_start_kernel+0x173/0x186 [18942.846234] verify_cpu+0x0/0xfc [18942.849604] irq event stamp: 30568 [18942.853140] hardirqs last enabled at (30567): [<ffffffff8110b81f>] ktime_get+0xef/0x120 [18942.861468] hardirqs last disabled at (30568): [<ffffffff81876377>] _raw_spin_lock_irqsave+0x17/0 x60 [18942.870812] softirqs last enabled at (30462): [<ffffffff81085cd9>] __do_softirq+0x1d9/0x4c0 [18942.879443] softirqs last disabled at (30439): [<ffffffff81086139>] irq_exit+0xa9/0xc0 [18942.887616] [18942.887616] other info that might help us debug this: [18942.894279] Possible unsafe locking scenario: [18942.894279] [18942.900336] CPU0 [18942.902851] ---- [18942.905362] lock(&(&fence->lock)->rlock); [18942.909647] <Interrupt> [18942.912330] lock(&(&fence->lock)->rlock); [18942.916821] [18942.916821] *** DEADLOCK *** [18942.916821] [18942.922862] 1 lock held by gem_eio/1275: [18942.926859] #0: (&(&fence->lock)->rlock){+.?...}, at: [<ffffffff815ec100>] dma_fence_signal+0x1 00/0x230 [18942.936651] [18942.936651] stack backtrace: [18942.941142] CPU: 3 PID: 1275 Comm: gem_eio Tainted: G U W 4.11.0-rc2-CI-CI_DRM_2368+ # 1 [18942.950367] Hardware name: Gigabyte Technology Co., Ltd. Z170X-UD5/Z170X-UD5-CF, BIOS F21 01/06/2 017 [18942.959756] Call Trace: [18942.962244] dump_stack+0x67/0x92 [18942.965626] print_usage_bug.part.23+0x259/0x268 [18942.970362] mark_lock+0x12c/0x6f0 [18942.973851] ? check_usage_forwards+0x130/0x130 [18942.978487] mark_held_locks+0x6f/0xa0 [18942.982329] ? _raw_spin_unlock_irq+0x27/0x50 [18942.986797] trace_hardirqs_on_caller+0x150/0x200 [18942.991599] trace_hardirqs_on+0xd/0x10 [18942.995515] _raw_spin_unlock_irq+0x27/0x50 [18942.999796] intel_engine_wakeup+0x26/0x30 [i915] [18943.004670] intel_engine_init_global_seqno+0x131/0x1a0 [i915] [18943.010745] nop_submit_request+0x2e/0x40 [i915] [18943.015476] submit_notify+0x3f/0x5c [i915] [18943.019763] __i915_sw_fence_complete+0x176/0x220 [i915] [18943.025234] ? try_to_del_timer_sync+0x4d/0x60 [18943.029825] i915_sw_fence_complete+0x25/0x40 [i915] [18943.034887] dma_i915_sw_fence_wake+0x26/0x60 [i915] [18943.039959] dma_fence_signal+0x146/0x230 [18943.044109] vgem_fence_signal_ioctl+0x6c/0xc0 [vgem] [18943.049275] drm_ioctl+0x200/0x450 [18943.052758] ? vgem_fence_attach_ioctl+0x270/0x270 [vgem] [18943.058334] do_vfs_ioctl+0x90/0x6e0 [18943.061991] ? entry_SYSCALL_64_fastpath+0x5/0xb1 [18943.066843] ? __this_cpu_preempt_check+0x13/0x20 [18943.071643] ? trace_hardirqs_on_caller+0xe7/0x200 [18943.076532] SyS_ioctl+0x3c/0x70 [18943.079842] entry_SYSCALL_64_fastpath+0x1c/0xb1 [18943.084558] RIP: 0033:0x7f0dfcc14357 [18943.088240] RSP: 002b:00007ffeb4628da8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [18943.095996] RAX: ffffffffffffffda RBX: ffffffff8147eb93 RCX: 00007f0dfcc14357 [18943.103311] RDX: 00007ffeb4628de0 RSI: 0000000040086442 RDI: 0000000000000005 [18943.110574] RBP: ffffc9000176ff88 R08: 0000000000000004 R09: 0000000000000000 [18943.117845] R10: 0000000000000029 R11: 0000000000000246 R12: 0000000000000001 [18943.125168] R13: 0000000000000005 R14: 0000000040086442 R15: 0000000000000000 [18943.132520] ? __this_cpu_preempt_check+0x13/0x20 Fixes: cdc3a4539034 ("drm/i915: No need to save/restore irq status in intel_engine_wakeup") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Mika Kuoppala <mika.kuoppala@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170320143133.1507-1-chris@chris-wilson.co.uk Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.