The patch titled
gpio: fix pca953x set_type 'scheduling while atomic' bug
has been removed from the -mm tree. Its filename was
fix-pca953x-set_type-scheduling-while-atomic-bug.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: gpio: fix pca953x set_type 'scheduling while atomic' bug
From: Marc Zyngier <maz@xxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxxxxxxx: coding-style fixes]
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxxxxxxx>
Reported-by: Bill Gatliff <bgat@xxxxxxxxxxxxxxx>
Cc: Eric Miao <eric.y.miao@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/gpio/pca953x.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff -puN drivers/gpio/pca953x.c~fix-pca953x-set_type-scheduling-while-atomic-bug drivers/gpio/pca953x.c
--- a/drivers/gpio/pca953x.c~fix-pca953x-set_type-scheduling-while-atomic-bug
+++ a/drivers/gpio/pca953x.c
@@ -252,6 +252,18 @@ static void pca953x_irq_bus_lock(unsigne
static void pca953x_irq_bus_sync_unlock(unsigned int irq)
{
struct pca953x_chip *chip = get_irq_chip_data(irq);
+ uint16_t new_irqs;
+ uint16_t level;
+
+ /* Look for any newly setup interrupt */
+ new_irqs = chip->irq_trig_fall | chip->irq_trig_raise;
+ new_irqs &= ~chip->reg_direction;
+
+ while (new_irqs) {
+ level = __ffs(new_irqs);
+ pca953x_gpio_direction_input(&chip->gpio_chip, level);
+ new_irqs &= ~(1 << level);
+ }
mutex_unlock(&chip->irq_lock);
}
@@ -278,7 +290,7 @@ static int pca953x_irq_set_type(unsigned
else
chip->irq_trig_raise &= ~mask;
- return pca953x_gpio_direction_input(&chip->gpio_chip, level);
+ return 0;
}
static struct irq_chip pca953x_irq_chip = {
_
Patches currently in -mm which might be from maz@xxxxxxxxxxxxxxx are
origin.patch
linux-next.patch
rtc-ds1302-add-some-abstraction-for-new-platform-support.patch
gpio-add-interrupt-handling-capability-to-max732x.patch
gpio-max732x-fix-input-configuration-for-open-drain-pins.patch
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