Re: [PATCH] pinctrl: pinmux: Don't free pins requested by other devices

From: Linus Walleij
Date: Wed Aug 07 2013 - 12:23:27 EST


On Wed, Jul 17, 2013 at 7:31 AM, Sonic Zhang <sonic.adi@xxxxxxxxx> wrote:

I'd like Stephen and Axel to have a look at this as well...

> From: Sonic Zhang <sonic.zhang@xxxxxxxxxx>
>
> in pinmux_disable_setting after current device fails to request
> the same pins.
>
> Signed-off-by: Sonic Zhang <sonic.zhang@xxxxxxxxxx>

I don't quite understand the patch. Can you provide more context?

> diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
> index 88cc509..9ebcf3b 100644
> --- a/drivers/pinctrl/pinmux.c
> +++ b/drivers/pinctrl/pinmux.c
> @@ -482,13 +482,14 @@ void pinmux_disable_setting(struct pinctrl_setting const *setting)
> pins[i]);
> continue;
> }
> + /* And release the pins */
> + if (desc->mux_usecount &&
> + !strcmp(desc->mux_owner, setting->dev_name))
> + pin_free(pctldev, pins[i], NULL);
> +
> desc->mux_setting = NULL;
> }
>
> - /* And release the pins */
> - for (i = 0; i < num_pins; i++)
> - pin_free(pctldev, pins[i], NULL);
> -

For pinmux_disable_setting() to inspect desc->mux_usecount seems
assymetric. This is something pin_free() should do, shouldn't it?

Should not this codepath be kept and a change made inside pin_free()
for the check above instead?

Yours,
Linus Walleij
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