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pinctrl: core: Add proper mutex lock in pinctrl_request_gpio

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

I think this fixes the race between pin_free() and pin_request() calls.
It protects accessing the members of pctldev->desc.
(e.g. update desc->mux_usecount, desc->gpio_owner, desc->mux_owner, etc)
Current code grabs pctldev->mutex before calling pinmux_free_gpio(),
but did not grab the mutex while calling pinmux_request_gpio().

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Axel Lin 2013-08-19 10:07:46 +08:00 committed by Linus Walleij
parent 406044695f
commit 9b77ace409
1 changed files with 4 additions and 0 deletions
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4
drivers/pinctrl/core.c
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@ -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;
}
EXPORT_SYMBOL_GPL(pinctrl_request_gpio);