The patch titled gpio: fix pca953x set_type 'scheduling while atomic' bug has been added to the -mm tree. Its filename is fix-pca953x-set_type-scheduling-while-atomic-bug.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this 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. 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 linux-next.patch fix-pca953x-set_type-scheduling-while-atomic-bug.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 -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html