From: Alexandru Ardelean <alexandru.ardelean@analog.com>
To: <linux-iio@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Cc: <jic23@kernel.org>, Alexandru Ardelean <alexandru.ardelean@analog.com>
Subject: [PATCH 3/3] iio: imu: adis: add a note better explaining state_lock
Date: Fri, 21 Feb 2020 13:49:43 +0200 [thread overview]
Message-ID: <20200221114943.2056-3-alexandru.ardelean@analog.com> (raw)
In-Reply-To: <20200221114943.2056-1-alexandru.ardelean@analog.com>
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 11c915b61ae2..a3110c097fa1 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
next prev parent reply other threads:[~2020-02-21 11:47 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-21 11:49 [PATCH 1/3] iio: imu: adis: add doc-string for 'adis' struct Alexandru Ardelean
2020-02-21 11:49 ` [PATCH 2/3] iio: imu: adis: update 'adis_data' struct doc-string Alexandru Ardelean
2020-02-21 13:13 ` Jonathan Cameron
2020-02-21 11:49 ` Alexandru Ardelean [this message]
2020-02-21 13:14 ` [PATCH 3/3] iio: imu: adis: add a note better explaining state_lock Jonathan Cameron
2020-02-21 13:11 ` [PATCH 1/3] iio: imu: adis: add doc-string for 'adis' struct Jonathan Cameron
2020-02-21 15:59 ` Ardelean, Alexandru
2020-02-21 16:14 ` Jonathan Cameron
2020-02-21 16:51 ` Ardelean, Alexandru
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200221114943.2056-3-alexandru.ardelean@analog.com \
--to=alexandru.ardelean@analog.com \
--cc=jic23@kernel.org \
--cc=linux-iio@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).