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From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Linus Walleij <linus.walleij@linaro.org>,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>,
	linux-gpio@vger.kernel.org,
	Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Subject: [PATCH v2 02/24] pinctrl: lynxpoint: Use raw_spinlock for locking
Date: Mon,  9 Dec 2019 15:09:04 +0200	[thread overview]
Message-ID: <20191209130926.86483-3-andriy.shevchenko@linux.intel.com> (raw)
In-Reply-To: <20191209130926.86483-1-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 490ce7bae25e..c30fd86846a7 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 */
@@ -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);
-- 
2.24.0


  parent reply	other threads:[~2019-12-09 13:09 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-09 13:09 [PATCH v2 00/24] pinctrl: intel: Move Lynxpoint to pin control umbrella Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 01/24] pinctrl: lynxpoint: Move GPIO driver to pin controller folder Andy Shevchenko
2019-12-09 13:09 ` Andy Shevchenko [this message]
2019-12-09 13:09 ` [PATCH v2 03/24] pinctrl: lynxpoint: Correct amount of pins Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 04/24] pinctrl: lynxpoint: Drop useless assignment Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 05/24] pinctrl: lynxpoint: Use %pR to print IO resource Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 06/24] pinctrl: lynxpoint: Use standard pattern for memory allocation Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 07/24] pinctrl: lynxpoint: Assume 2 bits for mode selector Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 08/24] pinctrl: lynxpoint: Relax GPIO request rules Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 09/24] pinctrl: lynxpoint: Keep pointer to struct device instead of its container Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 10/24] pinctrl: lynxpoint: Switch to memory mapped IO accessors Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 11/24] pinctrl: lynxpoint: Convert unsigned to unsigned int Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 12/24] pinctrl: lynxpoint: Extract lp_gpio_acpi_use() for future use Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 13/24] pinctrl: lynxpoint: Move ->remove closer to ->probe() Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 14/24] pinctrl: lynxpoint: Move lp_irq_type() closer to IRQ related routines Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 15/24] pinctrl: lynxpoint: Move ownership check to IRQ chip Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 16/24] pinctrl: lynxpoint: Implement ->irq_ack() callback Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 17/24] pinctrl: lynxpoint: Implement intel_gpio_get_direction callback Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 18/24] pinctrl: lynxpoint: Add pin control data structures Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 19/24] pinctrl: lynxpoint: Reuse struct intel_pinctrl in the driver Andy Shevchenko
2019-12-10  5:26   ` kbuild test robot
2019-12-10 13:46     ` Andy Shevchenko
2019-12-10 13:47       ` Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 20/24] pinctrl: lynxpoint: Add pin control operations Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 21/24] pinctrl: lynxpoint: Implement ->pin_dbg_show() Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 22/24] pinctrl: lynxpoint: Add GPIO <-> pin mapping ranges via callback Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 23/24] pinctrl: lynxpoint: Switch to pin control API Andy Shevchenko
2019-12-09 13:09 ` [PATCH v2 24/24] pinctrl: lynxpoint: Update summary in the driver Andy Shevchenko
2019-12-11 13:19 ` [PATCH v2 00/24] pinctrl: intel: Move Lynxpoint to pin control umbrella Mika Westerberg
2019-12-13 13:36 ` Linus Walleij
2019-12-13 14:44   ` Andy Shevchenko
2019-12-16 10:19     ` Linus Walleij

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