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.

Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
---
 drivers/gpio/gpio-omap.c |   78 +++++++++++++++++++++++------------------------
 1 file changed, 39 insertions(+), 39 deletions(-)

--- 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;
@@ -498,14 +498,14 @@ static int omap_gpio_irq_type(struct irq
                (type & (IRQ_TYPE_LEVEL_LOW|IRQ_TYPE_LEVEL_HIGH)))
                return -EINVAL;
 
-       spin_lock_irqsave(&bank->lock, flags);
+       raw_spin_lock_irqsave(&bank->lock, flags);
        retval = omap_set_gpio_triggering(bank, offset, type);
        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);
                return -EINVAL;
        }
-       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->irq, handle_level_irq);
@@ -626,14 +626,14 @@ static int omap_set_gpio_wakeup(struct g
                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;
 }
@@ -668,7 +668,7 @@ static int omap_gpio_request(struct gpio
        if (!BANK_USED(bank))
                pm_runtime_get_sync(bank->dev);
 
-       spin_lock_irqsave(&bank->lock, flags);
+       raw_spin_lock_irqsave(&bank->lock, flags);
        /* Set trigger to none. You need to enable the desired trigger with
         * request_irq() or set_irq_type(). Only do this if the IRQ line has
         * not already been requested.
@@ -678,7 +678,7 @@ static int omap_gpio_request(struct gpio
                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;
 }
@@ -688,11 +688,11 @@ static void omap_gpio_free(struct gpio_c
        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));
        omap_disable_gpio_module(bank, offset);
        omap_reset_gpio(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,
@@ -794,9 +794,9 @@ static unsigned int omap_gpio_irq_startu
        if (!BANK_USED(bank))
                pm_runtime_get_sync(bank->dev);
 
-       spin_lock_irqsave(&bank->lock, flags);
+       raw_spin_lock_irqsave(&bank->lock, flags);
        omap_gpio_init_irq(bank, offset);
-       spin_unlock_irqrestore(&bank->lock, flags);
+       raw_spin_unlock_irqrestore(&bank->lock, flags);
        omap_gpio_unmask_irq(d);
 
        return 0;
@@ -808,11 +808,11 @@ static void omap_gpio_irq_shutdown(struc
        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_disable_gpio_module(bank, offset);
        omap_reset_gpio(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,
@@ -836,10 +836,10 @@ static void omap_gpio_mask_irq(struct ir
        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)
@@ -849,7 +849,7 @@ static void omap_gpio_unmask_irq(struct
        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);
 
@@ -861,7 +861,7 @@ static void omap_gpio_unmask_irq(struct
        }
 
        omap_set_gpio_irqenable(bank, offset, 1);
-       spin_unlock_irqrestore(&bank->lock, flags);
+       raw_spin_unlock_irqrestore(&bank->lock, flags);
 }
 
 /*---------------------------------------------------------------------*/
@@ -874,9 +874,9 @@ static int omap_mpuio_suspend_noirq(stru
                                        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;
 }
@@ -889,9 +889,9 @@ static int omap_mpuio_resume_noirq(struc
                                        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;
 }
@@ -937,9 +937,9 @@ static int omap_gpio_get_direction(struc
 
        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;
 }
 
@@ -949,9 +949,9 @@ static int omap_gpio_input(struct gpio_c
        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;
 }
 
@@ -973,10 +973,10 @@ static int omap_gpio_output(struct gpio_
        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;
 }
 
@@ -988,9 +988,9 @@ static int omap_gpio_debounce(struct gpi
 
        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;
 }
@@ -1001,9 +1001,9 @@ static void omap_gpio_set(struct gpio_ch
        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);
 }
 
 /*---------------------------------------------------------------------*/
@@ -1199,7 +1199,7 @@ static int omap_gpio_probe(struct platfo
        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);
@@ -1246,7 +1246,7 @@ static int omap_gpio_runtime_suspend(str
        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.
@@ -1299,7 +1299,7 @@ static int omap_gpio_runtime_suspend(str
                                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;
 }
@@ -1314,7 +1314,7 @@ static int omap_gpio_runtime_resume(stru
        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
@@ -1350,14 +1350,14 @@ static int omap_gpio_runtime_resume(stru
                        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;
        }
 
@@ -1412,7 +1412,7 @@ static int omap_gpio_runtime_resume(stru
        }
 
        bank->workaround_enabled = false;
-       spin_unlock_irqrestore(&bank->lock, flags);
+       raw_spin_unlock_irqrestore(&bank->lock, flags);
 
        return 0;
 }
--
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