gpio: fix pca953x set_type 'scheduling while atomic' bug
Bill Gatliff reported the following bug when using the irq_chip facility of the pca953x driver on a PPC platform: BUG: scheduling while atomic: insmod/1530/0x00000002 He traced it back to an i2c transaction in pca953x_irq_set_type(), which can be called with interrupt disabled (from __setup_irq()). As the i2c controller can sleep while sending a message, this qualifies as a bad idea. This patch moves the i2c transaction to pca953x_irq_bus_sync_unlock(), where it is actually safe to send an i2c message. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Marc Zyngier <maz@misterjones.org> Reported-by: Bill Gatliff <bgat@billgatliff.com> Cc: Eric Miao <eric.y.miao@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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@ -252,6 +252,18 @@ static void pca953x_irq_bus_lock(unsigned int irq)
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static void pca953x_irq_bus_sync_unlock(unsigned int irq)
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static void pca953x_irq_bus_sync_unlock(unsigned int irq)
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{
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{
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struct pca953x_chip *chip = get_irq_chip_data(irq);
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struct pca953x_chip *chip = get_irq_chip_data(irq);
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uint16_t new_irqs;
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uint16_t level;
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/* Look for any newly setup interrupt */
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new_irqs = chip->irq_trig_fall | chip->irq_trig_raise;
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new_irqs &= ~chip->reg_direction;
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while (new_irqs) {
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level = __ffs(new_irqs);
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pca953x_gpio_direction_input(&chip->gpio_chip, level);
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new_irqs &= ~(1 << level);
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}
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mutex_unlock(&chip->irq_lock);
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mutex_unlock(&chip->irq_lock);
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}
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}
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@ -278,7 +290,7 @@ static int pca953x_irq_set_type(unsigned int irq, unsigned int type)
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else
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else
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chip->irq_trig_raise &= ~mask;
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chip->irq_trig_raise &= ~mask;
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return pca953x_gpio_direction_input(&chip->gpio_chip, level);
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return 0;
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}
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}
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static struct irq_chip pca953x_irq_chip = {
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static struct irq_chip pca953x_irq_chip = {
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