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Commit a3727b0a authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Greg Kroah-Hartman
Browse files

mfd: arizona: Fix undefined behavior 



[ Upstream commit 5da6cbcd2f395981aa9bfc571ace99f1c786c985 ]

When the driver is used with a subdevice that is disabled in the
kernel configuration, clang gets a little confused about the
control flow and fails to notice that n_subdevs is only
uninitialized when subdevs is NULL, and we check for that,
leading to a false-positive warning:

drivers/mfd/arizona-core.c:1423:19: error: variable 'n_subdevs' is uninitialized when used here
      [-Werror,-Wuninitialized]
                              subdevs, n_subdevs, NULL, 0, NULL);
                                       ^~~~~~~~~
drivers/mfd/arizona-core.c:999:15: note: initialize the variable 'n_subdevs' to silence this warning
        int n_subdevs, ret, i;
                     ^
                      = 0

Ideally, we would rearrange the code to avoid all those early
initializations and have an explicit exit in each disabled case,
but it's much easier to chicken out and add one more initialization
here to shut up the warning.

Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Reviewed-by: default avatarNathan Chancellor <natechancellor@gmail.com>
Signed-off-by: default avatarCharles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent f1405059

drivers/mfd/arizona-core.c

+1 −1
Original line number Diff line number Diff line
@@ -1038,7 +1038,7 @@ int arizona_dev_init(struct arizona *arizona) 
	unsigned int reg, val, mask;

	int (*apply_patch)(struct arizona *) = NULL;

	const struct mfd_cell *subdevs = NULL;

	int n_subdevs, ret, i;

	int n_subdevs = 0, ret, i;



	dev_set_drvdata(arizona->dev, arizona);

	mutex_init(&arizona->clk_lock);