Messages in this thread Patch in this message | | | From | Alexandru Ardelean <> | Subject | [PATCH v2 3/3] iio: imu: adis: add a note better explaining state_lock | Date | Tue, 25 Feb 2020 12:33:19 +0200 |
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The 'state_lock' mutex was renamed from 'txrx_lock' in a previous patch and is intended to be used by ADIS drivers to protect the state of devices during consecutive R/W ops. The initial patch that introduced this change did not do a good [well, any] job at explaining this. This patch adds a comment to the 'state_lock' better explaining it's use.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> --- include/linux/iio/imu/adis.h | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/include/linux/iio/imu/adis.h b/include/linux/iio/imu/adis.h index 20339025c75f..dd8219138c2e 100644 --- a/include/linux/iio/imu/adis.h +++ b/include/linux/iio/imu/adis.h @@ -98,6 +98,17 @@ struct adis { const struct adis_data *data; struct adis_burst *burst; + /** + * The state_lock is meant to be used during operations that require + * a sequence of SPI R/W in order to protect the SPI transfer + * information (fields 'xfer', 'msg' & 'current_page') between + * potential concurrent accesses. + * This lock is used by all "adis_{functions}" that have to read/write + * registers. These functions also have unlocked variants + * (see "__adis_{functions}"), which don't hold this lock. + * This allows users of the ADIS library to group SPI R/W into + * the drivers, but they also must manage this lock themselves. + */ struct mutex state_lock; struct spi_message msg; struct spi_transfer *xfer; -- 2.20.1
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