Re: [PATCH 05/19] gpio: 104-dio-48e: make use of raw_spinlock variants

From: Linus Walleij
Date: Wed Mar 15 2017 - 05:55:00 EST


On Thu, Mar 9, 2017 at 5:21 PM, Julia Cartwright <julia@xxxxxx> wrote:

> The 104-dio-48e 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>

Patch applied with Williams ACK.

Yours,
Linus Walleij