pinctrl: core: Add proper mutex lock in pinctrl_request_gpio
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>
diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index 7094a81..054d14b 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -562,11 +562,15 @@
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);