/* * linux/kernel/irq/pm.c * * Copyright (C) 2009 Rafael J. Wysocki , Novell Inc. * * This file contains power management functions related to interrupts. */ #include #include #include #include #include #include "internals.h" bool irq_pm_check_wakeup(struct irq_desc *desc) { if (irqd_is_wakeup_armed(&desc->irq_data)) { irqd_clear(&desc->irq_data, IRQD_WAKEUP_ARMED); desc->istate |= IRQS_SUSPENDED | IRQS_PENDING; desc->depth++; irq_disable(desc); pm_system_irq_wakeup(irq_desc_get_irq(desc)); return true; } return false; } /* * Called from __setup_irq() with desc->lock held after @action has * been installed in the action chain. */ void irq_pm_install_action(struct irq_desc *desc, struct irqaction *action) { desc->nr_actions++; if (action->flags & IRQF_FORCE_RESUME) desc->force_resume_depth++; WARN_ON_ONCE(desc->force_resume_depth && desc->force_resume_depth != desc->nr_actions); if (action->flags & IRQF_NO_SUSPEND) desc->no_suspend_depth++; else if (action->flags & IRQF_COND_SUSPEND) desc->cond_suspend_depth++; WARN_ON_ONCE(desc->no_suspend_depth && (desc->no_suspend_depth + desc->cond_suspend_depth) != desc->nr_actions); } /* * Called from __free_irq() with desc->lock held after @action has * been removed from the action chain. */ void irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action) { desc->nr_actions--; if (action->flags & IRQF_FORCE_RESUME) desc->force_resume_depth--; if (action->flags & IRQF_NO_SUSPEND) desc->no_suspend_depth--; else if (action->flags & IRQF_COND_SUSPEND) desc->cond_suspend_depth--; } static bool suspend_device_irq(struct irq_desc *desc) { if (!desc->action || irq_desc_is_chained(desc) || desc->no_suspend_depth) return false; if (irqd_is_wakeup_set(&desc->irq_data)) { irqd_set(&desc->irq_data, IRQD_WAKEUP_ARMED); /* * We return true here to force the caller to issue * synchronize_irq(). We need to make sure that the * IRQD_WAKEUP_ARMED is visible before we return from * suspend_device_irqs(). */ return true; } desc->istate |= IRQS_SUSPENDED; __disable_irq(desc); /* * Hardware which has no wakeup source configuration facility * requires that the non wakeup interrupts are masked at the * chip level. The chip implementation indicates that with * IRQCHIP_MASK_ON_SUSPEND. */ if (irq_desc_get_chip(desc)->flags & IRQCHIP_MASK_ON_SUSPEND) mask_irq(desc); return true; } /** * suspend_device_irqs - disable all currently enabled interrupt lines * * During system-wide suspend or hibernation device drivers need to be * prevented from receiving interrupts and this function is provided * for this purpose. * * So we disable all interrupts and mark them IRQS_SUSPENDED except * for those which are unused, those which are marked as not * suspendable via an interrupt request with the flag IRQF_NO_SUSPEND * set and those which are marked as active wakeup sources. * * The active wakeup sources are handled by the flow handler entry * code which checks for the IRQD_WAKEUP_ARMED flag, suspends the * interrupt and notifies the pm core about the wakeup. */ void suspend_device_irqs(void) { struct irq_desc *desc; int irq; for_each_irq_desc(irq, desc) { unsigned long flags; bool sync; if (irq_settings_is_nested_thread(desc)) continue; raw_spin_lock_irqsave(&desc->lock, flags); sync = suspend_device_irq(desc); raw_spin_unlock_irqrestore(&desc->lock, flags); if (sync) synchronize_irq(irq); } } EXPORT_SYMBOL_GPL(suspend_device_irqs); static void resume_irq(struct irq_desc *desc) { irqd_clear(&desc->irq_data, IRQD_WAKEUP_ARMED); if (desc->istate & IRQS_SUSPENDED) goto resume; /* Force resume the interrupt? */ if (!desc->force_resume_depth) return; /* Pretend that it got disabled ! */ desc->depth++; resume: desc->istate &= ~IRQS_SUSPENDED; __enable_irq(desc); } static void resume_irqs(bool want_early) { struct irq_desc *desc; int irq; for_each_irq_desc(irq, desc) { unsigned long flags; bool is_early = desc->action && desc->action->flags & IRQF_EARLY_RESUME; if (!is_early && want_early) continue; if (irq_settings_is_nested_thread(desc)) continue; raw_spin_lock_irqsave(&desc->lock, flags); resume_irq(desc); raw_spin_unlock_irqrestore(&desc->lock, flags); } } /** * irq_pm_syscore_ops - enable interrupt lines early * * Enable all interrupt lines with %IRQF_EARLY_RESUME set. */ static void irq_pm_syscore_resume(void) { resume_irqs(true); } static struct syscore_ops irq_pm_syscore_ops = { .resume = irq_pm_syscore_resume, }; static int __init irq_pm_init_ops(void) { register_syscore_ops(&irq_pm_syscore_ops); return 0; } device_initcall(irq_pm_init_ops); /** * resume_device_irqs - enable interrupt lines disabled by suspend_device_irqs() * * Enable all non-%IRQF_EARLY_RESUME interrupt lines previously * disabled by suspend_device_irqs() that have the IRQS_SUSPENDED flag * set as well as those with %IRQF_FORCE_RESUME. */ void resume_device_irqs(void) { resume_irqs(false); } EXPORT_SYMBOL_GPL(resume_device_irqs); dfba96c543e55b6672d5a37e'>98fe974ee4e20121253de7f61fc8d01bdb3821c1 /net/xfrm/xfrm_hash.c parent2c5d9555d6d937966d79d4c6529a5f7b9206e405 (diff)
drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()
I've seen this trigger twice now, where the i915_gem_object_to_ggtt() call in intel_unpin_fb_obj() returns NULL, resulting in an oops immediately afterwards as the (inlined) call to i915_vma_unpin_fence() tries to dereference it. It seems to be some race condition where the object is going away at shutdown time, since both times happened when shutting down the X server. The call chains were different: - VT ioctl(KDSETMODE, KD_TEXT): intel_cleanup_plane_fb+0x5b/0xa0 [i915] drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper] intel_atomic_commit_tail+0x749/0xfe0 [i915] intel_atomic_commit+0x3cb/0x4f0 [i915] drm_atomic_commit+0x4b/0x50 [drm] restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper] drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper] drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper] intel_fbdev_set_par+0x18/0x70 [i915] fb_set_var+0x236/0x460 fbcon_blank+0x30f/0x350 do_unblank_screen+0xd2/0x1a0 vt_ioctl+0x507/0x12a0 tty_ioctl+0x355/0xc30 do_vfs_ioctl+0xa3/0x5e0 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x13/0x94 - i915 unpin_work workqueue: intel_unpin_work_fn+0x58/0x140 [i915] process_one_work+0x1f1/0x480 worker_thread+0x48/0x4d0 kthread+0x101/0x140 and this patch purely papers over the issue by adding a NULL pointer check and a WARN_ON_ONCE() to avoid the oops that would then generally make the machine unresponsive. Other callers of i915_gem_object_to_ggtt() seem to also check for the returned pointer being NULL and warn about it, so this clearly has happened before in other places. [ Reported it originally to the i915 developers on Jan 8, applying the ugly workaround on my own now after triggering the problem for the second time with no feedback. This is likely to be the same bug reported as https://bugs.freedesktop.org/show_bug.cgi?id=98829 https://bugs.freedesktop.org/show_bug.cgi?id=99134 which has a patch for the underlying problem, but it hasn't gotten to me, so I'm applying the workaround. ] Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Imre Deak <imre.deak@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'net/xfrm/xfrm_hash.c')