Re: [PATCH 3/3] iio: imu: adis: add a note better explaining state_lock

From: Jonathan Cameron <jic23@kernel.org>
To: Alexandru Ardelean <alexandru.ardelean@analog.com>
Cc: <linux-iio@vger.kernel.org>
Subject: Re: [PATCH 3/3] iio: imu: adis: add a note better explaining state_lock
Date: Sat, 12 Oct 2019 12:50:15 +0100	[thread overview]
Message-ID: <20191012125015.6cd3f714@archlinux> (raw)
In-Reply-To: <20191008080239.23239-3-alexandru.ardelean@analog.com>

On Tue, 8 Oct 2019 11:02:39 +0300
Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:

> 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>
Tiny tweak. See below.

Applied to the togreg branch of iio.git and pushed out as testing.

One thing to note though.  I don't normally run kernel-doc on random
headers, and my eyes missed it, but there are errors in the docs
for read and write functions that could do with fixing.

[jic23@archlinux iio]$ ./scripts/kernel-doc  include/linux/iio/imu/adis.h > temp.html
include/linux/iio/imu/adis.h:138: warning: Function parameter or member 'val' not described in '__adis_write_reg_8'
include/linux/iio/imu/adis.h:138: warning: Excess function parameter 'value' description in '__adis_write_reg_8'
include/linux/iio/imu/adis.h:150: warning: Function parameter or member 'val' not described in '__adis_write_reg_16'
include/linux/iio/imu/adis.h:150: warning: Excess function parameter 'value' description in '__adis_write_reg_16'
include/linux/iio/imu/adis.h:162: warning: Function parameter or member 'val' not described in '__adis_write_reg_32'
include/linux/iio/imu/adis.h:162: warning: Excess function parameter 'value' description in '__adis_write_reg_32'
include/linux/iio/imu/adis.h:217: warning: Function parameter or member 'val' not described in 'adis_write_reg'
include/linux/iio/imu/adis.h:217: warning: Excess function parameter 'value' description in 'adis_write_reg'
include/linux/iio/imu/adis.h:254: warning: Function parameter or member 'val' not described in 'adis_write_reg_8'
include/linux/iio/imu/adis.h:254: warning: Excess function parameter 'value' description in 'adis_write_reg_8'
include/linux/iio/imu/adis.h:266: warning: Function parameter or member 'val' not described in 'adis_write_reg_16'
include/linux/iio/imu/adis.h:266: warning: Excess function parameter 'value' description in 'adis_write_reg_16'
include/linux/iio/imu/adis.h:278: warning: Function parameter or member 'val' not described in 'adis_write_reg_32'
include/linux/iio/imu/adis.h:278: warning: Excess function parameter 'value' description in 'adis_write_reg_32'

If you could role a patch for those, that would be great.  Thanks!

Thanks,

Jonathan

> ---
>  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 27ebd740f626..abd4bd07e960 100644
> --- a/include/linux/iio/imu/adis.h
> +++ b/include/linux/iio/imu/adis.h
> @@ -80,6 +80,17 @@ struct adis {
>  	const struct adis_data	*data;
>  	struct adis_burst	*burst;
>  
> +	/**
This isn't kernel doc so
 /* 

I'll fix.

> +	 * 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;