/* * Copyright (C) 2010 Red Hat, Inc., Peter Zijlstra * * Provides a framework for enqueueing and running callbacks from hardirq * context. The enqueueing is NMI-safe. */ #include #include #include #include #include #include #include #include #include #include #include #include #include static DEFINE_PER_CPU(struct llist_head, raised_list); static DEFINE_PER_CPU(struct llist_head, lazy_list); /* * Claim the entry so that no one else will poke at it. */ static bool irq_work_claim(struct irq_work *work) { unsigned long flags, oflags, nflags; /* * Start with our best wish as a premise but only trust any * flag value after cmpxchg() result. */ flags = work->flags & ~IRQ_WORK_PENDING; for (;;) { nflags = flags | IRQ_WORK_FLAGS; oflags = cmpxchg(&work->flags, flags, nflags); if (oflags == flags) break; if (oflags & IRQ_WORK_PENDING) return false; flags = oflags; cpu_relax(); } return true; } void __weak arch_irq_work_raise(void) { /* * Lame architectures will get the timer tick callback */ } #ifdef CONFIG_SMP /* * Enqueue the irq_work @work on @cpu unless it's already pending * somewhere. * * Can be re-enqueued while the callback is still in progress. */ bool irq_work_queue_on(struct irq_work *work, int cpu) { /* All work should have been flushed before going offline */ WARN_ON_ONCE(cpu_is_offline(cpu)); /* Arch remote IPI send/receive backend aren't NMI safe */ WARN_ON_ONCE(in_nmi()); /* Only queue if not already pending */ if (!irq_work_claim(work)) return false; if (llist_add(&work->llnode, &per_cpu(raised_list, cpu))) arch_send_call_function_single_ipi(cpu); return true; } EXPORT_SYMBOL_GPL(irq_work_queue_on); #endif /* Enqueue the irq work @work on the current CPU */ bool irq_work_queue(struct irq_work *work) { /* Only queue if not already pending */ if (!irq_work_claim(work)) return false; /* Queue the entry and raise the IPI if needed. */ preempt_disable(); /* If the work is "lazy", handle it from next tick if any */ if (work->flags & IRQ_WORK_LAZY) { if (llist_add(&work->llnode, this_cpu_ptr(&lazy_list)) && tick_nohz_tick_stopped()) arch_irq_work_raise(); } else { if (llist_add(&work->llnode, this_cpu_ptr(&raised_list))) arch_irq_work_raise(); } preempt_enable(); return true; } EXPORT_SYMBOL_GPL(irq_work_queue); bool irq_work_needs_cpu(void) { struct llist_head *raised, *lazy; raised = this_cpu_ptr(&raised_list); lazy = this_cpu_ptr(&lazy_list); if (llist_empty(raised) || arch_irq_work_has_interrupt()) if (llist_empty(lazy)) return false; /* All work should have been flushed before going offline */ WARN_ON_ONCE(cpu_is_offline(smp_processor_id())); return true; } static void irq_work_run_list(struct llist_head *list) { unsigned long flags; struct irq_work *work; struct llist_node *llnode; BUG_ON(!irqs_disabled()); if (llist_empty(list)) return; llnode = llist_del_all(list); while (llnode != NULL) { work = llist_entry(llnode, struct irq_work, llnode); llnode = llist_next(llnode); /* * Clear the PENDING bit, after this point the @work * can be re-used. * Make it immediately visible so that other CPUs trying * to claim that work don't rely on us to handle their data * while we are in the middle of the func. */ flags = work->flags & ~IRQ_WORK_PENDING; xchg(&work->flags, flags); work->func(work); /* * Clear the BUSY bit and return to the free state if * no-one else claimed it meanwhile. */ (void)cmpxchg(&work->flags, flags, flags & ~IRQ_WORK_BUSY); } } /* * hotplug calls this through: * hotplug_cfd() -> flush_smp_call_function_queue() */ void irq_work_run(void) { irq_work_run_list(this_cpu_ptr(&raised_list)); irq_work_run_list(this_cpu_ptr(&lazy_list)); } EXPORT_SYMBOL_GPL(irq_work_run); void irq_work_tick(void) { struct llist_head *raised = this_cpu_ptr(&raised_list); if (!llist_empty(raised) && !arch_irq_work_has_interrupt()) irq_work_run_list(raised); irq_work_run_list(this_cpu_ptr(&lazy_list)); } /* * Synchronize against the irq_work @entry, ensures the entry is not * currently in use. */ void irq_work_sync(struct irq_work *work) { WARN_ON_ONCE(irqs_disabled()); while (work->flags & IRQ_WORK_BUSY) cpu_relax(); } EXPORT_SYMBOL_GPL(irq_work_sync); ption>mode:
authorChen-Yu Tsai <wens@csie.org>2016-11-11 11:12:43 +0800
committerMark Brown <broonie@kernel.org>2016-11-11 15:34:45 +0000
commit618c808968852609d2d9f0e5cfc351a4807ef8d0 (patch)
tree01a8d928c06fe7bef488f55bade6ba37b958bb5f /include/sound/ak4531_codec.h
parent1001354ca34179f3db924eb66672442a173147dc (diff)
regulator: axp20x: Fix axp809 ldo_io registration error on cold boot
The maximum supported voltage for ldo_io# is 3.3V, but on cold boot the selector comes up at 0x1f, which maps to 3.8V. This was previously corrected by Allwinner's U-boot, which set all regulators on the PMICs to some pre-configured voltage. With recent progress in U-boot SPL support, this is no longer the case. In any case we should handle this quirk in the kernel driver as well. This invalid setting causes _regulator_get_voltage() to fail with -EINVAL which causes regulator registration to fail when constrains are used: [ 1.054181] vcc-pg: failed to get the current voltage(-22) [ 1.059670] axp20x-regulator axp20x-regulator.0: Failed to register ldo_io0 [ 1.069749] axp20x-regulator: probe of axp20x-regulator.0 failed with error -22 This commits makes the axp20x regulator driver accept the 0x1f register value, fixing this. The datasheet does not guarantee reliable operation above 3.3V, so on boards where this regulator is used the regulator-max-microvolt setting must be 3.3V or less. This is essentially the same as the commit f40d4896bf32 ("regulator: axp20x: Fix axp22x ldo_io registration error on cold boot") for AXP22x PMICs. Fixes: a51f9f4622a3 ("regulator: axp20x: support AXP809 variant") Signed-off-by: Chen-Yu Tsai <wens@csie.org> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'include/sound/ak4531_codec.h')