From 4dbada2be460dc5568fa27784ef626232c28061f Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Tue, 21 Jul 2015 18:26:51 +0200 Subject: gpio: omap: use raw locks for locking This patch converts gpio_bank.lock from a spin_lock into a raw_spin_lock. The call path is to access this lock is always under a raw_spin_lock, for instance - __setup_irq() holds &desc->lock with irq off + __irq_set_trigger() + omap_gpio_irq_type() - handle_level_irq() (runs with irqs off therefore raw locks) + mask_ack_irq() + omap_gpio_mask_irq() This fixes the obvious backtrace on -RT. However the locking vs context is not and this is not limited to -RT: - omap_gpio_irq_type() is called with IRQ off and has an conditional call to pm_runtime_get_sync() which may sleep. Either it may happen or it may not happen but pm_runtime_get_sync() should not be called with irqs off. - omap_gpio_debounce() is holding the lock with IRQs off. + omap2_set_gpio_debounce() + clk_prepare_enable() + clk_prepare() this one might sleep. The number of users of gpiod_set_debounce() / gpio_set_debounce() looks low but still this is not good. Acked-by: Javier Martinez Canillas Acked-by: Santosh Shilimkar Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Linus Walleij diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c index 04ea23b..a2ff0ee 100644 --- a/drivers/gpio/gpio-omap.c +++ b/drivers/gpio/gpio-omap.c @@ -57,7 +57,7 @@ struct gpio_bank { u32 saved_datain; u32 level_mask; u32 toggle_mask; - spinlock_t lock; + raw_spinlock_t lock; struct gpio_chip chip; struct clk *dbck; u32 mod_usage; @@ -498,17 +498,17 @@ static int omap_gpio_irq_type(struct irq_data *d, unsigned type) if (!BANK_USED(bank)) pm_runtime_get_sync(bank->dev); - spin_lock_irqsave(&bank->lock, flags); + raw_spin_lock_irqsave(&bank->lock, flags); retval = omap_set_gpio_triggering(bank, offset, type); if (retval) goto error; omap_gpio_init_irq(bank, offset); if (!omap_gpio_is_input(bank, offset)) { - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); retval = -EINVAL; goto error; } - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH)) irq_set_handler_locked(d, handle_level_irq); @@ -634,14 +634,14 @@ static int omap_set_gpio_wakeup(struct gpio_bank *bank, unsigned offset, return -EINVAL; } - spin_lock_irqsave(&bank->lock, flags); + raw_spin_lock_irqsave(&bank->lock, flags); if (enable) bank->context.wake_en |= gpio_bit; else bank->context.wake_en &= ~gpio_bit; writel_relaxed(bank->context.wake_en, bank->base + bank->regs->wkup_en); - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); return 0; } @@ -667,10 +667,10 @@ static int omap_gpio_request(struct gpio_chip *chip, unsigned offset) if (!BANK_USED(bank)) pm_runtime_get_sync(bank->dev); - spin_lock_irqsave(&bank->lock, flags); + raw_spin_lock_irqsave(&bank->lock, flags); omap_enable_gpio_module(bank, offset); bank->mod_usage |= BIT(offset); - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); return 0; } @@ -680,14 +680,14 @@ static void omap_gpio_free(struct gpio_chip *chip, unsigned offset) struct gpio_bank *bank = container_of(chip, struct gpio_bank, chip); unsigned long flags; - spin_lock_irqsave(&bank->lock, flags); + raw_spin_lock_irqsave(&bank->lock, flags); bank->mod_usage &= ~(BIT(offset)); if (!LINE_USED(bank->irq_usage, offset)) { omap_set_gpio_direction(bank, offset, 1); omap_clear_gpio_debounce(bank, offset); } omap_disable_gpio_module(bank, offset); - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); /* * If this is the last gpio to be freed in the bank, @@ -789,7 +789,7 @@ static unsigned int omap_gpio_irq_startup(struct irq_data *d) if (!BANK_USED(bank)) pm_runtime_get_sync(bank->dev); - spin_lock_irqsave(&bank->lock, flags); + raw_spin_lock_irqsave(&bank->lock, flags); if (!LINE_USED(bank->mod_usage, offset)) omap_set_gpio_direction(bank, offset, 1); @@ -798,12 +798,12 @@ static unsigned int omap_gpio_irq_startup(struct irq_data *d) omap_enable_gpio_module(bank, offset); bank->irq_usage |= BIT(offset); - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); omap_gpio_unmask_irq(d); return 0; err: - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); if (!BANK_USED(bank)) pm_runtime_put(bank->dev); return -EINVAL; @@ -815,7 +815,7 @@ static void omap_gpio_irq_shutdown(struct irq_data *d) unsigned long flags; unsigned offset = d->hwirq; - spin_lock_irqsave(&bank->lock, flags); + raw_spin_lock_irqsave(&bank->lock, flags); bank->irq_usage &= ~(BIT(offset)); omap_set_gpio_irqenable(bank, offset, 0); omap_clear_gpio_irqstatus(bank, offset); @@ -823,7 +823,7 @@ static void omap_gpio_irq_shutdown(struct irq_data *d) if (!LINE_USED(bank->mod_usage, offset)) omap_clear_gpio_debounce(bank, offset); omap_disable_gpio_module(bank, offset); - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); /* * If this is the last IRQ to be freed in the bank, @@ -847,10 +847,10 @@ static void omap_gpio_mask_irq(struct irq_data *d) unsigned offset = d->hwirq; unsigned long flags; - spin_lock_irqsave(&bank->lock, flags); + raw_spin_lock_irqsave(&bank->lock, flags); omap_set_gpio_irqenable(bank, offset, 0); omap_set_gpio_triggering(bank, offset, IRQ_TYPE_NONE); - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); } static void omap_gpio_unmask_irq(struct irq_data *d) @@ -860,7 +860,7 @@ static void omap_gpio_unmask_irq(struct irq_data *d) u32 trigger = irqd_get_trigger_type(d); unsigned long flags; - spin_lock_irqsave(&bank->lock, flags); + raw_spin_lock_irqsave(&bank->lock, flags); if (trigger) omap_set_gpio_triggering(bank, offset, trigger); @@ -872,7 +872,7 @@ static void omap_gpio_unmask_irq(struct irq_data *d) } omap_set_gpio_irqenable(bank, offset, 1); - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); } /*---------------------------------------------------------------------*/ @@ -885,9 +885,9 @@ static int omap_mpuio_suspend_noirq(struct device *dev) OMAP_MPUIO_GPIO_MASKIT / bank->stride; unsigned long flags; - spin_lock_irqsave(&bank->lock, flags); + raw_spin_lock_irqsave(&bank->lock, flags); writel_relaxed(0xffff & ~bank->context.wake_en, mask_reg); - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); return 0; } @@ -900,9 +900,9 @@ static int omap_mpuio_resume_noirq(struct device *dev) OMAP_MPUIO_GPIO_MASKIT / bank->stride; unsigned long flags; - spin_lock_irqsave(&bank->lock, flags); + raw_spin_lock_irqsave(&bank->lock, flags); writel_relaxed(bank->context.wake_en, mask_reg); - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); return 0; } @@ -948,9 +948,9 @@ static int omap_gpio_get_direction(struct gpio_chip *chip, unsigned offset) bank = container_of(chip, struct gpio_bank, chip); reg = bank->base + bank->regs->direction; - spin_lock_irqsave(&bank->lock, flags); + raw_spin_lock_irqsave(&bank->lock, flags); dir = !!(readl_relaxed(reg) & BIT(offset)); - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); return dir; } @@ -960,9 +960,9 @@ static int omap_gpio_input(struct gpio_chip *chip, unsigned offset) unsigned long flags; bank = container_of(chip, struct gpio_bank, chip); - spin_lock_irqsave(&bank->lock, flags); + raw_spin_lock_irqsave(&bank->lock, flags); omap_set_gpio_direction(bank, offset, 1); - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); return 0; } @@ -984,10 +984,10 @@ static int omap_gpio_output(struct gpio_chip *chip, unsigned offset, int value) unsigned long flags; bank = container_of(chip, struct gpio_bank, chip); - spin_lock_irqsave(&bank->lock, flags); + raw_spin_lock_irqsave(&bank->lock, flags); bank->set_dataout(bank, offset, value); omap_set_gpio_direction(bank, offset, 0); - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); return 0; } @@ -999,9 +999,9 @@ static int omap_gpio_debounce(struct gpio_chip *chip, unsigned offset, bank = container_of(chip, struct gpio_bank, chip); - spin_lock_irqsave(&bank->lock, flags); + raw_spin_lock_irqsave(&bank->lock, flags); omap2_set_gpio_debounce(bank, offset, debounce); - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); return 0; } @@ -1012,9 +1012,9 @@ static void omap_gpio_set(struct gpio_chip *chip, unsigned offset, int value) unsigned long flags; bank = container_of(chip, struct gpio_bank, chip); - spin_lock_irqsave(&bank->lock, flags); + raw_spin_lock_irqsave(&bank->lock, flags); bank->set_dataout(bank, offset, value); - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); } /*---------------------------------------------------------------------*/ @@ -1210,7 +1210,7 @@ static int omap_gpio_probe(struct platform_device *pdev) else bank->set_dataout = omap_set_gpio_dataout_mask; - spin_lock_init(&bank->lock); + raw_spin_lock_init(&bank->lock); /* Static mapping, never released */ res = platform_get_resource(pdev, IORESOURCE_MEM, 0); @@ -1268,7 +1268,7 @@ static int omap_gpio_runtime_suspend(struct device *dev) unsigned long flags; u32 wake_low, wake_hi; - spin_lock_irqsave(&bank->lock, flags); + raw_spin_lock_irqsave(&bank->lock, flags); /* * Only edges can generate a wakeup event to the PRCM. @@ -1321,7 +1321,7 @@ update_gpio_context_count: bank->get_context_loss_count(bank->dev); omap_gpio_dbck_disable(bank); - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); return 0; } @@ -1336,7 +1336,7 @@ static int omap_gpio_runtime_resume(struct device *dev) unsigned long flags; int c; - spin_lock_irqsave(&bank->lock, flags); + raw_spin_lock_irqsave(&bank->lock, flags); /* * On the first resume during the probe, the context has not @@ -1372,14 +1372,14 @@ static int omap_gpio_runtime_resume(struct device *dev) if (c != bank->context_loss_count) { omap_gpio_restore_context(bank); } else { - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); return 0; } } } if (!bank->workaround_enabled) { - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); return 0; } @@ -1434,7 +1434,7 @@ static int omap_gpio_runtime_resume(struct device *dev) } bank->workaround_enabled = false; - spin_unlock_irqrestore(&bank->lock, flags); + raw_spin_unlock_irqrestore(&bank->lock, flags); return 0; } -- cgit v0.10.2