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authorAxel Lin <axel.lin@ingics.com>2013-08-19 04:07:46 +0200
committerLinus Walleij <linus.walleij@linaro.org>2013-08-28 13:13:05 +0200
commit9b77ace409e1419c331209c4c8eb2c8bc990e9fd (patch)
tree0bb3a43aee693c3fe68924a2dfc07254ef3f69b3
parentpinctrl: imx: Fix compilation with DEBUG enabled (diff)
downloadlinux-9b77ace409e1419c331209c4c8eb2c8bc990e9fd.tar.xz
linux-9b77ace409e1419c331209c4c8eb2c8bc990e9fd.zip
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>
-rw-r--r--drivers/pinctrl/core.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index 7094a8129008..054d14b43db4 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;
}
EXPORT_SYMBOL_GPL(pinctrl_request_gpio);