Re: [PATCH v2 8/9] gpio: 104-idio-16: make use of raw_spinlock variants
From: Linus Walleij
Date: Tue Mar 28 2017 - 05:14:12 EST
On Tue, Mar 21, 2017 at 11:43 PM, Julia Cartwright <julia@xxxxxx> wrote:
> The 104-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@xxxxxx>
> ---
> New patch as of v2 of series.
Patch applied to the GPIO tree with William's ACK.
Yours,
Linus Walleij