* [RFC] staging: iio: ad7759: Replace mlock with driver private buf_lock
@ 2017-03-28 17:37 Arushi Singhal
2017-03-29 21:16 ` Jonathan Cameron
0 siblings, 1 reply; 2+ messages in thread
From: Arushi Singhal @ 2017-03-28 17:37 UTC (permalink / raw)
To: lars
Cc: Michael Hennerich, Jonathan Cameron, Hartmut Knaack,
Peter Meerwald-Stadler, Greg Kroah-Hartman, linux-iio, devel,
linux-kernel, outreachy-kernel
The IIO subsystem is redefining iio_dev->mlock to be used by
the IIO core only for protecting device operating mode changes.
ie. Changes between INDIO_DIRECT_MODE, INDIO_BUFFER_* modes.
In this driver, mlock was being used to protect hardware state
changes. Replace it with a buf_lock in the devices global data.
Signed-off-by: Arushi Singhal <arushisinghal19971997@gmail.com>
---
drivers/staging/iio/meter/ade7759.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/staging/iio/meter/ade7759.c b/drivers/staging/iio/meter/ade7759.c
index 0b65f1847510..514a4f6bb8f9 100644
--- a/drivers/staging/iio/meter/ade7759.c
+++ b/drivers/staging/iio/meter/ade7759.c
@@ -429,7 +429,7 @@ static ssize_t ade7759_write_frequency(struct device *dev,
if (!val)
return -EINVAL;
- mutex_lock(&indio_dev->mlock);
+ mutex_lock(&st->buf_lock);
t = 27900 / val;
if (t > 0)
@@ -447,10 +447,13 @@ static ssize_t ade7759_write_frequency(struct device *dev,
reg &= ~(3 << 13);
reg |= t << 13;
- ret = ade7759_spi_write_reg_16(dev, ADE7759_MODE, reg);
+ st->tx[0] = ADE7754_WRITE_REG(ADE7754_WAVMODE);
+ st->tx[1] = reg;
+
+ ret = spi_write(st->us, st->tx, 2);
out:
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&st->buf_lock);
return ret ? ret : len;
}
--
2.11.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [RFC] staging: iio: ad7759: Replace mlock with driver private buf_lock
2017-03-28 17:37 [RFC] staging: iio: ad7759: Replace mlock with driver private buf_lock Arushi Singhal
@ 2017-03-29 21:16 ` Jonathan Cameron
0 siblings, 0 replies; 2+ messages in thread
From: Jonathan Cameron @ 2017-03-29 21:16 UTC (permalink / raw)
To: Arushi Singhal, lars
Cc: Michael Hennerich, Hartmut Knaack, Peter Meerwald-Stadler,
Greg Kroah-Hartman, linux-iio, devel, linux-kernel,
outreachy-kernel
On 28/03/17 18:37, Arushi Singhal wrote:
> The IIO subsystem is redefining iio_dev->mlock to be used by
> the IIO core only for protecting device operating mode changes.
> ie. Changes between INDIO_DIRECT_MODE, INDIO_BUFFER_* modes.
>
> In this driver, mlock was being used to protect hardware state
> changes. Replace it with a buf_lock in the devices global data.
>
> Signed-off-by: Arushi Singhal <arushisinghal19971997@gmail.com>
Rule 1 of an RFC. Explain why it is an RFC rather than simply a
patch. What needs comment here in particular?
One thing that needs doing is a documentation update to reflect
the additional elements buf_lock is now protecting.
I think the use is sensible and can't otherwise see any issue with
this patch.
Thanks,
Jonathan
> ---
> drivers/staging/iio/meter/ade7759.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/staging/iio/meter/ade7759.c b/drivers/staging/iio/meter/ade7759.c
> index 0b65f1847510..514a4f6bb8f9 100644
> --- a/drivers/staging/iio/meter/ade7759.c
> +++ b/drivers/staging/iio/meter/ade7759.c
> @@ -429,7 +429,7 @@ static ssize_t ade7759_write_frequency(struct device *dev,
> if (!val)
> return -EINVAL;
>
> - mutex_lock(&indio_dev->mlock);
> + mutex_lock(&st->buf_lock);
>
> t = 27900 / val;
> if (t > 0)
> @@ -447,10 +447,13 @@ static ssize_t ade7759_write_frequency(struct device *dev,
> reg &= ~(3 << 13);
> reg |= t << 13;
>
> - ret = ade7759_spi_write_reg_16(dev, ADE7759_MODE, reg);
> + st->tx[0] = ADE7754_WRITE_REG(ADE7754_WAVMODE);
> + st->tx[1] = reg;
> +
> + ret = spi_write(st->us, st->tx, 2);
>
> out:
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&st->buf_lock);
>
> return ret ? ret : len;
> }
>
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