This is a note to let you know that I've just added the patch titled

iio: light: vcnl4000: Fix WARN_ON on uninitialized lock

to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From 42ec40b0883c1cce58b06e8fa82049a61033151c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?M=C3=A5rten=20Lindahl?= marten.lindahl@axis.com Date: Tue, 31 Jan 2023 15:01:09 +0100 Subject: iio: light: vcnl4000: Fix WARN_ON on uninitialized lock MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

There are different init functions for the sensors in this driver in which only one initializes the generic vcnl4000_lock. With commit e21b5b1f2669 ("iio: light: vcnl4000: Preserve conf bits when toggle power") the vcnl4040 sensor started to depend on the lock, but it was missed to initialize it in vcnl4040's init function. This has not been visible until we run lockdep on it:

DEBUG_LOCKS_WARN_ON(lock->magic != lock) at kernel/locking/mutex.c:575 __mutex_lock+0x4f8/0x890 Call trace: __mutex_lock mutex_lock_nested vcnl4200_set_power_state vcnl4200_init vcnl4000_probe

Fix this by initializing the lock in the probe function instead of doing it in the chip specific init functions.

Fixes: e21b5b1f2669 ("iio: light: vcnl4000: Preserve conf bits when toggle power") Signed-off-by: Mårten Lindahl marten.lindahl@axis.com Reviewed-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Link: https://lore.kernel.org/r/20230131140109.2067577-1-marten.lindahl@axis.com Cc: Stable@vger.kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com --- drivers/iio/light/vcnl4000.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/light/vcnl4000.c b/drivers/iio/light/vcnl4000.c index cc1a2062e76d..69c5bc987e26 100644 --- a/drivers/iio/light/vcnl4000.c +++ b/drivers/iio/light/vcnl4000.c @@ -199,7 +199,6 @@ static int vcnl4000_init(struct vcnl4000_data *data)

data->rev = ret & 0xf; data->al_scale = 250000; - mutex_init(&data->vcnl4000_lock);

return data->chip_spec->set_power_state(data, true); }; @@ -1197,6 +1196,8 @@ static int vcnl4000_probe(struct i2c_client *client) data->id = id->driver_data; data->chip_spec = &vcnl4000_chip_spec_cfg[data->id];

+ mutex_init(&data->vcnl4000_lock); + ret = data->chip_spec->init(data); if (ret < 0) return ret;