From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Mika Westerberg <mika.westerberg@linux.intel.com>,
linux-gpio@vger.kernel.org,
Bartosz Golaszewski <bgolaszewski@baylibre.com>,
Linus Walleij <linus.walleij@linaro.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Subject: [PATCH v1 2/8] pinctrl: lynxpoint: Use raw_spinlock for locking
Date: Wed, 6 Nov 2019 16:48:23 +0200 [thread overview]
Message-ID: <20191106144829.32275-3-andriy.shevchenko@linux.intel.com> (raw)
In-Reply-To: <20191106144829.32275-1-andriy.shevchenko@linux.intel.com>
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.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
drivers/pinctrl/intel/pinctrl-lynxpoint.c | 28 +++++++++++------------
1 file changed, 14 insertions(+), 14 deletions(-)
diff --git a/drivers/pinctrl/intel/pinctrl-lynxpoint.c b/drivers/pinctrl/intel/pinctrl-lynxpoint.c
index e9e47c0d5be7..6467095523cc 100644
--- a/drivers/pinctrl/intel/pinctrl-lynxpoint.c
+++ b/drivers/pinctrl/intel/pinctrl-lynxpoint.c
@@ -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 */
@@ -164,7 +164,7 @@ static int lp_irq_type(struct irq_data *d, unsigned type)
value |= TRIG_SEL_BIT | INT_INV_BIT;
outl(value, reg);
- spin_unlock_irqrestore(&lg->lock, flags);
+ raw_spin_unlock_irqrestore(&lg->lock, flags);
return 0;
}
@@ -181,14 +181,14 @@ 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)
@@ -197,9 +197,9 @@ 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;
}
@@ -213,9 +213,9 @@ 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;
}
@@ -266,9 +266,9 @@ 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)
@@ -279,9 +279,9 @@ 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 = {
@@ -345,7 +345,7 @@ 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);
--
2.24.0.rc1
next prev parent reply other threads:[~2019-11-06 14:48 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-06 14:48 [PATCH v1 0/8] pinctrl: intel: Move Lynxpoint to pin control umbrella Andy Shevchenko
2019-11-06 14:48 ` [PATCH v1 1/8] pinctrl: lynxpoint: Move GPIO driver to pin controller folder Andy Shevchenko
2019-11-07 13:48 ` Mika Westerberg
2019-11-07 14:47 ` Andy Shevchenko
2019-11-13 9:54 ` Linus Walleij
2019-11-13 13:40 ` Andy Shevchenko
2019-11-06 14:48 ` Andy Shevchenko [this message]
2019-11-06 14:48 ` [PATCH v1 3/8] pinctrl: lynxpoint: Correct amount of pins Andy Shevchenko
2019-11-06 14:48 ` [PATCH v1 4/8] pinctrl: lynxpoint: Keep pointer to struct device instead of its container Andy Shevchenko
2019-11-06 14:48 ` [PATCH v1 5/8] pinctrl: lynxpoint: Use %pR to print IO resource Andy Shevchenko
2019-11-06 14:48 ` [PATCH v1 6/8] pinctrl: lynxpoint: Switch to memory mapped IO accessors Andy Shevchenko
2019-11-06 14:48 ` [PATCH v1 7/8] pinctrl: lynxpoint: Convert unsigned to unsigned int Andy Shevchenko
2019-11-06 14:48 ` [PATCH v1 8/8] pinctrl: lynxpoint: Move ->remove closer to ->probe() Andy Shevchenko
2019-11-13 9:54 ` [PATCH v1 0/8] pinctrl: intel: Move Lynxpoint to pin control umbrella Linus Walleij
2019-11-25 12:02 ` Andy Shevchenko
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