Home
last modified time | relevance | path

Searched hist:ea38ce08 (Results 1 – 1 of 1) sorted by relevance

/openbmc/linux/drivers/gpio/
H A Dgpio-pci-idio-16.cea38ce08 Tue Mar 21 17:43:09 CDT 2017 Julia Cartwright <julia@ni.com> gpio: pci-idio-16: make use of raw_spinlock variants

The pci-idio-16 gpio driver currently implements an irq_chip for handling
interrupts; due to how irq_chip handling is done, it's necessary for the
irq_chip methods to be invoked from hardirq context, even on a a
real-time kernel. Because the spinlock_t type becomes a "sleeping"
spinlock w/ RT kernels, it is not suitable to be used with irq_chips.

A quick audit of the operations under the lock reveal that they do only
minimal, bounded work, and are therefore safe to do under a raw spinlock.

Signed-off-by: Julia Cartwright <julia@ni.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
ea38ce08 Tue Mar 21 17:43:09 CDT 2017 Julia Cartwright <julia@ni.com> gpio: pci-idio-16: make use of raw_spinlock variants

The pci-idio-16 gpio driver currently implements an irq_chip for handling
interrupts; due to how irq_chip handling is done, it's necessary for the
irq_chip methods to be invoked from hardirq context, even on a a
real-time kernel. Because the spinlock_t type becomes a "sleeping"
spinlock w/ RT kernels, it is not suitable to be used with irq_chips.

A quick audit of the operations under the lock reveal that they do only
minimal, bounded work, and are therefore safe to do under a raw spinlock.

Signed-off-by: Julia Cartwright <julia@ni.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>