From: Jonathan Cameron <jic23@kernel.org>
To: Tallys Martins <tallysmartins@gmail.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>,
Michael Hennerich <Michael.Hennerich@analog.com>,
Stefan Popa <stefan.popa@analog.com>,
Hartmut Knaack <knaack.h@gmx.de>,
Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-iio@vger.kernel.org, devel@driverdev.osuosl.org,
linux-kernel@vger.kernel.or, kernel-usp@googlegroups.com,
Souza Guilherme <gdsdsilva@inf.ufpel.edu.br>
Subject: Re: [PATCH 1/2] staging: iio: ad2s1210: Destroy mutex at remove
Date: Sun, 19 May 2019 12:12:09 +0100 [thread overview]
Message-ID: <20190519121209.71524d18@archlinux> (raw)
In-Reply-To: <20190518221558.21799-1-tallysmartins@gmail.com>
On Sat, 18 May 2019 19:15:57 -0300
Tallys Martins <tallysmartins@gmail.com> wrote:
> Ensure the mutex will be destroyed on drive removal.
> Also adds mutex comment description.
>
> Signed-off-by: Tallys Martins <tallysmartins@gmail.com>
> Signed-off-by: Souza Guilherme <gdsdsilva@inf.ufpel.edu.br>
> Co-developed-by: Souza Guilherme <gdsdsilva@inf.ufpel.edu.br>
Hi.
This particular 'issue' is never a simple one.
The destroy_mutex call is intended for lock debugging only,
which is why there is devm_init_mutex or similar to allow for
automatic unwinding.
It simple cleanup paths like this, it provides very little value
and leads to a more complex unwind.
It is for this reason that the vast majority of drivers simply
don't bother.
Hence, unless there is a good reason I'm missing I won't be
introducing more of them.
Thanks,
Jonathan
> ---
> drivers/staging/iio/resolver/ad2s1210.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/staging/iio/resolver/ad2s1210.c b/drivers/staging/iio/resolver/ad2s1210.c
> index b6be0bc202f5..b91cf57c5e57 100644
> --- a/drivers/staging/iio/resolver/ad2s1210.c
> +++ b/drivers/staging/iio/resolver/ad2s1210.c
> @@ -86,7 +86,7 @@ static const struct ad2s1210_gpio gpios[] = {
> static const unsigned int ad2s1210_resolution_value[] = { 10, 12, 14, 16 };
>
> struct ad2s1210_state {
> - struct mutex lock;
> + struct mutex lock; /* lock to protect the state on r/w operations */
> struct spi_device *sdev;
> struct gpio_desc *gpios[5];
> unsigned int fclkin;
> @@ -689,8 +689,10 @@ static int ad2s1210_probe(struct spi_device *spi)
> static int ad2s1210_remove(struct spi_device *spi)
> {
> struct iio_dev *indio_dev = spi_get_drvdata(spi);
> + struct ad2s1210_state *ad2s1210_ad = iio_priv(indio_dev);
>
> iio_device_unregister(indio_dev);
> + mutex_destroy(&ad2s1210_ad->lock);
>
> return 0;
> }
prev parent reply other threads:[~2019-05-19 17:47 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-18 22:15 [PATCH 1/2] staging: iio: ad2s1210: Destroy mutex at remove Tallys Martins
2019-05-18 22:15 ` [PATCH 2/2] staging: iio: ad2s1210: Add devicetree yaml doc Tallys Martins
2019-05-19 11:17 ` Jonathan Cameron
2019-05-20 10:17 ` Alexandru Ardelean
2019-05-19 11:12 ` Jonathan Cameron [this message]
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