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pinctrl: lynxpoint: Use raw_spinlock for locking 

The Intel Lynxpoint pinctrl driver implements irqchip callbacks which are
called with desc->lock raw_spinlock held. In mainline this is fine because
spinlock resolves to raw_spinlock. However, running the same code in -rt
we will get a BUG() asserted.

This is because in -rt spinlocks are preemptible so taking the driver
private spinlock in irqchip callbacks causes might_sleep() to trigger.

In order to keep -rt happy but at the same time make sure that register
accesses get serialized, convert the driver to use raw_spinlock instead.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
This commit is contained in:
Andy Shevchenko 2019-11-18 20:04:54 +02:00
parent eb83479e18
commit b2e05d63c2
1 changed files with 14 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
drivers/pinctrl/intel/pinctrl-lynxpoint.c
View File

@ -47,7 +47,7 @@
struct lp_gpio {
struct gpio_chip chip;
struct platform_device *pdev;
spinlock_t lock;
raw_spinlock_t lock;
unsigned long reg_base;
};
@ -144,7 +144,7 @@ static int lp_irq_type(struct irq_data *d, unsigned type)
if (hwirq >= lg->chip.ngpio)
return -EINVAL;
spin_lock_irqsave(&lg->lock, flags);
raw_spin_lock_irqsave(&lg->lock, flags);
value = inl(reg);
/* set both TRIG_SEL and INV bits to 0 for rising edge */
@ -170,7 +170,7 @@ static int lp_irq_type(struct irq_data *d, unsigned type)
else if (type & IRQ_TYPE_LEVEL_MASK)
irq_set_handler_locked(d, handle_level_irq);
spin_unlock_irqrestore(&lg->lock, flags);
raw_spin_unlock_irqrestore(&lg->lock, flags);
return 0;
}
@ -187,14 +187,14 @@ static void lp_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1);
unsigned long flags;
spin_lock_irqsave(&lg->lock, flags);
raw_spin_lock_irqsave(&lg->lock, flags);
if (value)
outl(inl(reg) | OUT_LVL_BIT, reg);
else
outl(inl(reg) & ~OUT_LVL_BIT, reg);
spin_unlock_irqrestore(&lg->lock, flags);
raw_spin_unlock_irqrestore(&lg->lock, flags);
}
static int lp_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
@ -203,9 +203,9 @@ static int lp_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
unsigned long reg = lp_gpio_reg(chip, offset, LP_CONFIG1);
unsigned long flags;
spin_lock_irqsave(&lg->lock, flags);
raw_spin_lock_irqsave(&lg->lock, flags);
outl(inl(reg) | DIR_BIT, reg);
spin_unlock_irqrestore(&lg->lock, flags);
raw_spin_unlock_irqrestore(&lg->lock, flags);
return 0;
}
@ -219,9 +219,9 @@ static int lp_gpio_direction_output(struct gpio_chip *chip,
lp_gpio_set(chip, offset, value);
spin_lock_irqsave(&lg->lock, flags);
raw_spin_lock_irqsave(&lg->lock, flags);
outl(inl(reg) & ~DIR_BIT, reg);
spin_unlock_irqrestore(&lg->lock, flags);
raw_spin_unlock_irqrestore(&lg->lock, flags);
return 0;
}
@ -272,9 +272,9 @@ static void lp_irq_enable(struct irq_data *d)
unsigned long reg = lp_gpio_reg(&lg->chip, hwirq, LP_INT_ENABLE);
unsigned long flags;
spin_lock_irqsave(&lg->lock, flags);
raw_spin_lock_irqsave(&lg->lock, flags);
outl(inl(reg) | BIT(hwirq % 32), reg);
spin_unlock_irqrestore(&lg->lock, flags);
raw_spin_unlock_irqrestore(&lg->lock, flags);
}
static void lp_irq_disable(struct irq_data *d)
@ -285,9 +285,9 @@ static void lp_irq_disable(struct irq_data *d)
unsigned long reg = lp_gpio_reg(&lg->chip, hwirq, LP_INT_ENABLE);
unsigned long flags;
spin_lock_irqsave(&lg->lock, flags);
raw_spin_lock_irqsave(&lg->lock, flags);
outl(inl(reg) & ~BIT(hwirq % 32), reg);
spin_unlock_irqrestore(&lg->lock, flags);
raw_spin_unlock_irqrestore(&lg->lock, flags);
}
static struct irq_chip lp_irqchip = {
@ -351,7 +351,7 @@ static int lp_gpio_probe(struct platform_device *pdev)
return -EBUSY;
}
spin_lock_init(&lg->lock);
raw_spin_lock_init(&lg->lock);
gc = &lg->chip;
gc->label = dev_name(dev);