From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Initial thought was to do something similar to __cond_lock()
do_iio_device_claim_direct_mode(iio_dev) ? : ({ __acquire(iio_dev); 0; })
+ Appropriate static inline iio_device_release_direct_mode()
However with that, sparse generates false positives. E.g.
drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c:1811:17: warning: context imbalance in 'st_lsm6dsx_read_raw' - unexpected unlock
So instead, this patch rethinks the return type and makes it more
'conditional lock like' (which is part of what is going on under the hood
anyway) and return a boolean - true for successfully acquired, false for
did not acquire.
To allow a migration path given the rework is now no trivial, take a leaf
out of the naming of the conditional guard we currently have for IIO
device direct mode and drop the _mode postfix from the new functions giving
iio_device_claim_direct() and iio_device_release_direct()
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
---
include/linux/iio/iio.h | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index 56161e02f002..4ef2f9893421 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -662,6 +662,28 @@ int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp);
int iio_device_claim_direct_mode(struct iio_dev *indio_dev);
void iio_device_release_direct_mode(struct iio_dev *indio_dev);
+/*
+ * Helper functions that allow claim and release of direct mode
+ * in a fashion that doesn't generate false positives from sparse.
+ */
+static inline bool iio_device_claim_direct(struct iio_dev *indio_dev) __cond_acquires(indio_dev)
+{
+ int ret = iio_device_claim_direct_mode(indio_dev);
+
+ if (ret)
+ return false;
+
+ __acquire(iio_dev);
+
+ return true;
+}
+
+static inline void iio_device_release_direct(struct iio_dev *indio_dev) __releases(indio_dev)
+{
+ iio_device_release_direct_mode(indio_dev);
+ __release(indio_dev);
+}
+
/*
* This autocleanup logic is normally used via
* iio_device_claim_direct_scoped().
--
2.47.1
