linux/debian/patches/features/all/rt/gpio-omap-use-raw-locks-for...

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10 KiB
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Thu, 12 Feb 2015 16:01:13 +0100
Subject: gpio: omap: use raw locks for locking
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.1/patches-4.1.3-rt3.tar.xz
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 <bigeasy@linutronix.de>
---
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;
}