From 80ac93c274411a55ae731f259f75e4ca5e499e8b Mon Sep 17 00:00:00 2001 From: Grygorii Strashko Date: Tue, 3 Oct 2017 11:17:05 -0500 Subject: [PATCH] gpio: omap: Fix lost edge interrupts Now acking of edge irqs happens the following way: - omap_gpio_irq_handler - "isr" = read irq status - omap_clear_gpio_irqbank(bank, isr_saved & ~level_mask); ^ clear edge status, so irq can be accepted - loop while "isr" generic_handle_irq() - handle_edge_irq() - desc->irq_data.chip->irq_ack(&desc->irq_data); - omap_gpio_ack_irq() it might be that at this moment edge IRQ was triggered again and it will be cleared and IRQ will be lost. Use handle_simple_irq and clear edge interrupts early without disabling them in omap_gpio_irq_handler to avoid loosing interrupts. [1] https://marc.info/?l=linux-omap&m=149004465313534&w=2 Signed-off-by: Grygorii Strashko Signed-off-by: Ladislav Michl Signed-off-by: Linus Walleij --- drivers/gpio/gpio-omap.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c index 22d7d4838265..3233b72b6828 100644 --- a/drivers/gpio/gpio-omap.c +++ b/drivers/gpio/gpio-omap.c @@ -518,7 +518,13 @@ static int omap_gpio_irq_type(struct irq_data *d, unsigned type) if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH)) irq_set_handler_locked(d, handle_level_irq); else if (type & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING)) - irq_set_handler_locked(d, handle_edge_irq); + /* + * Edge IRQs are already cleared/acked in irq_handler and + * not need to be masked, as result handle_edge_irq() + * logic is excessed here and may cause lose of interrupts. + * So just use handle_simple_irq. + */ + irq_set_handler_locked(d, handle_simple_irq); return 0; @@ -678,7 +684,7 @@ static void omap_gpio_free(struct gpio_chip *chip, unsigned offset) static irqreturn_t omap_gpio_irq_handler(int irq, void *gpiobank) { void __iomem *isr_reg = NULL; - u32 isr; + u32 enabled, isr, level_mask; unsigned int bit; struct gpio_bank *bank = gpiobank; unsigned long wa_lock_flags; @@ -691,23 +697,21 @@ static irqreturn_t omap_gpio_irq_handler(int irq, void *gpiobank) pm_runtime_get_sync(bank->chip.parent); while (1) { - u32 isr_saved, level_mask = 0; - u32 enabled; - raw_spin_lock_irqsave(&bank->lock, lock_flags); enabled = omap_get_gpio_irqbank_mask(bank); - isr_saved = isr = readl_relaxed(isr_reg) & enabled; + isr = readl_relaxed(isr_reg) & enabled; if (bank->level_mask) level_mask = bank->level_mask & enabled; + else + level_mask = 0; /* clear edge sensitive interrupts before handler(s) are called so that we don't miss any interrupt occurred while executing them */ - omap_disable_gpio_irqbank(bank, isr_saved & ~level_mask); - omap_clear_gpio_irqbank(bank, isr_saved & ~level_mask); - omap_enable_gpio_irqbank(bank, isr_saved & ~level_mask); + if (isr & ~level_mask) + omap_clear_gpio_irqbank(bank, isr & ~level_mask); raw_spin_unlock_irqrestore(&bank->lock, lock_flags); -- 2.20.1