Re: [PATCH 2/2] pinctrl: core: Add proper mutex lock in pinctrl_request_gpio

[Linus Walleij]

On Mon, Aug 19, 2013 at 4:07 AM, Axel Lin <axel.lin@xxxxxxxxxx> wrote:

> This one is missed in commit 42fed7ba "pinctrl: move subsystem mutex to
> pinctrl_dev struct".

I think this was never there.

> Signed-off-by: Axel Lin <axel.lin@xxxxxxxxxx>
> ---
>  drivers/pinctrl/core.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
> index 53c40d9..92f86ab 100644
> --- a/drivers/pinctrl/core.c
> +++ b/drivers/pinctrl/core.c
> @@ -562,11 +562,15 @@ int pinctrl_request_gpio(unsigned gpio)
>                 return ret;
>         }
>
> +       mutex_lock(&pctldev->mutex);
> +
>         /* Convert to the pin controllers number space */
>         pin = gpio_to_pin(range, gpio);
>
>         ret = pinmux_request_gpio(pctldev, range, pin, gpio);
>
> +       mutex_unlock(&pctldev->mutex);
> +
>         return ret;

What is this protecting against?

I'm not sure I follow this so better ask.

Yours,
Linus Walleij
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