* [PATCH] iio: dac: ti-dac7612: Replace indio_dev->mlock with own device lock
@ 2020-08-26 6:40 Alexandru Ardelean
2020-08-29 15:47 ` Jonathan Cameron
2020-09-16 9:25 ` [PATCH v2] " Alexandru Ardelean
0 siblings, 2 replies; 4+ messages in thread
From: Alexandru Ardelean @ 2020-08-26 6:40 UTC (permalink / raw)
To: linux-iio, linux-kernel
Cc: ribalda, jic23, Sergiu Cuciurean, Alexandru Ardelean
From: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
As part of the general cleanup of indio_dev->mlock, this change replaces
it with a local lock on the device's state structure.
Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---
drivers/iio/dac/ti-dac7612.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/iio/dac/ti-dac7612.c b/drivers/iio/dac/ti-dac7612.c
index 07c9f39d54f1..34c2aec204ef 100644
--- a/drivers/iio/dac/ti-dac7612.c
+++ b/drivers/iio/dac/ti-dac7612.c
@@ -21,6 +21,7 @@ struct dac7612 {
struct spi_device *spi;
struct gpio_desc *loaddacs;
uint16_t cache[2];
+ struct mutex lock;
/*
* DMA (thus cache coherency maintenance) requires the
@@ -101,9 +102,9 @@ static int dac7612_write_raw(struct iio_dev *iio_dev,
if (val == priv->cache[chan->channel])
return 0;
- mutex_lock(&iio_dev->mlock);
+ mutex_lock(&priv->lock);
ret = dac7612_cmd_single(priv, chan->channel, val);
- mutex_unlock(&iio_dev->mlock);
+ mutex_unlock(&priv->lock);
return ret;
}
@@ -145,6 +146,8 @@ static int dac7612_probe(struct spi_device *spi)
iio_dev->num_channels = ARRAY_SIZE(priv->cache);
iio_dev->name = spi_get_device_id(spi)->name;
+ mutex_init(&priv->lock);
+
for (i = 0; i < ARRAY_SIZE(priv->cache); i++) {
ret = dac7612_cmd_single(priv, i, 0);
if (ret)
--
2.25.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] iio: dac: ti-dac7612: Replace indio_dev->mlock with own device lock
2020-08-26 6:40 [PATCH] iio: dac: ti-dac7612: Replace indio_dev->mlock with own device lock Alexandru Ardelean
@ 2020-08-29 15:47 ` Jonathan Cameron
2020-09-16 9:25 ` [PATCH v2] " Alexandru Ardelean
1 sibling, 0 replies; 4+ messages in thread
From: Jonathan Cameron @ 2020-08-29 15:47 UTC (permalink / raw)
To: Alexandru Ardelean; +Cc: linux-iio, linux-kernel, ribalda, Sergiu Cuciurean
On Wed, 26 Aug 2020 09:40:28 +0300
Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:
> From: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
>
> As part of the general cleanup of indio_dev->mlock, this change replaces
> it with a local lock on the device's state structure.
>
> Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
> ---
> drivers/iio/dac/ti-dac7612.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/dac/ti-dac7612.c b/drivers/iio/dac/ti-dac7612.c
> index 07c9f39d54f1..34c2aec204ef 100644
> --- a/drivers/iio/dac/ti-dac7612.c
> +++ b/drivers/iio/dac/ti-dac7612.c
> @@ -21,6 +21,7 @@ struct dac7612 {
> struct spi_device *spi;
> struct gpio_desc *loaddacs;
> uint16_t cache[2];
> + struct mutex lock;
Looks fine with the exception of my usual request for a comment explaining
lock scope.
Thanks,
Jonathan
>
> /*
> * DMA (thus cache coherency maintenance) requires the
> @@ -101,9 +102,9 @@ static int dac7612_write_raw(struct iio_dev *iio_dev,
> if (val == priv->cache[chan->channel])
> return 0;
>
> - mutex_lock(&iio_dev->mlock);
> + mutex_lock(&priv->lock);
> ret = dac7612_cmd_single(priv, chan->channel, val);
> - mutex_unlock(&iio_dev->mlock);
> + mutex_unlock(&priv->lock);
>
> return ret;
> }
> @@ -145,6 +146,8 @@ static int dac7612_probe(struct spi_device *spi)
> iio_dev->num_channels = ARRAY_SIZE(priv->cache);
> iio_dev->name = spi_get_device_id(spi)->name;
>
> + mutex_init(&priv->lock);
> +
> for (i = 0; i < ARRAY_SIZE(priv->cache); i++) {
> ret = dac7612_cmd_single(priv, i, 0);
> if (ret)
^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH v2] iio: dac: ti-dac7612: Replace indio_dev->mlock with own device lock
2020-08-26 6:40 [PATCH] iio: dac: ti-dac7612: Replace indio_dev->mlock with own device lock Alexandru Ardelean
2020-08-29 15:47 ` Jonathan Cameron
@ 2020-09-16 9:25 ` Alexandru Ardelean
2020-09-16 17:56 ` Jonathan Cameron
1 sibling, 1 reply; 4+ messages in thread
From: Alexandru Ardelean @ 2020-09-16 9:25 UTC (permalink / raw)
To: linux-iio, linux-kernel
Cc: ribalda, jic23, Sergiu Cuciurean, Alexandru Ardelean
From: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
As part of the general cleanup of indio_dev->mlock, this change replaces
it with a local lock on the device's state from potential concurrent write
accesses from userspace. The write operation requires an SPI write, then
toggling of a GPIO, so the lock aims to protect the sanity of the entire
sequence of operation.
This is part of a bigger cleanup.
Link: https://lore.kernel.org/linux-iio/CA+U=Dsoo6YABe5ODLp+eFNPGFDjk5ZeQEceGkqjxXcVEhLWubw@mail.gmail.com/
Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---
drivers/iio/dac/ti-dac7612.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/iio/dac/ti-dac7612.c b/drivers/iio/dac/ti-dac7612.c
index 07c9f39d54f1..4c0f4b5e9ff4 100644
--- a/drivers/iio/dac/ti-dac7612.c
+++ b/drivers/iio/dac/ti-dac7612.c
@@ -22,6 +22,14 @@ struct dac7612 {
struct gpio_desc *loaddacs;
uint16_t cache[2];
+ /*
+ * Lock to protect the state of the device from potential concurrent
+ * write accesses from userspace. The write operation requires an
+ * SPI write, then toggling of a GPIO, so the lock aims to protect
+ * the sanity of the entire sequence of operation.
+ */
+ struct mutex lock;
+
/*
* DMA (thus cache coherency maintenance) requires the
* transfer buffers to live in their own cache lines.
@@ -101,9 +109,9 @@ static int dac7612_write_raw(struct iio_dev *iio_dev,
if (val == priv->cache[chan->channel])
return 0;
- mutex_lock(&iio_dev->mlock);
+ mutex_lock(&priv->lock);
ret = dac7612_cmd_single(priv, chan->channel, val);
- mutex_unlock(&iio_dev->mlock);
+ mutex_unlock(&priv->lock);
return ret;
}
@@ -145,6 +153,8 @@ static int dac7612_probe(struct spi_device *spi)
iio_dev->num_channels = ARRAY_SIZE(priv->cache);
iio_dev->name = spi_get_device_id(spi)->name;
+ mutex_init(&priv->lock);
+
for (i = 0; i < ARRAY_SIZE(priv->cache); i++) {
ret = dac7612_cmd_single(priv, i, 0);
if (ret)
--
2.17.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2] iio: dac: ti-dac7612: Replace indio_dev->mlock with own device lock
2020-09-16 9:25 ` [PATCH v2] " Alexandru Ardelean
@ 2020-09-16 17:56 ` Jonathan Cameron
0 siblings, 0 replies; 4+ messages in thread
From: Jonathan Cameron @ 2020-09-16 17:56 UTC (permalink / raw)
To: Alexandru Ardelean; +Cc: linux-iio, linux-kernel, ribalda, Sergiu Cuciurean
On Wed, 16 Sep 2020 12:25:35 +0300
Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:
> From: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
>
> As part of the general cleanup of indio_dev->mlock, this change replaces
> it with a local lock on the device's state from potential concurrent write
> accesses from userspace. The write operation requires an SPI write, then
> toggling of a GPIO, so the lock aims to protect the sanity of the entire
> sequence of operation.
>
> This is part of a bigger cleanup.
> Link: https://lore.kernel.org/linux-iio/CA+U=Dsoo6YABe5ODLp+eFNPGFDjk5ZeQEceGkqjxXcVEhLWubw@mail.gmail.com/
>
> Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to play with it.
Thanks,
Jonathan
> ---
> drivers/iio/dac/ti-dac7612.c | 14 ++++++++++++--
> 1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/dac/ti-dac7612.c b/drivers/iio/dac/ti-dac7612.c
> index 07c9f39d54f1..4c0f4b5e9ff4 100644
> --- a/drivers/iio/dac/ti-dac7612.c
> +++ b/drivers/iio/dac/ti-dac7612.c
> @@ -22,6 +22,14 @@ struct dac7612 {
> struct gpio_desc *loaddacs;
> uint16_t cache[2];
>
> + /*
> + * Lock to protect the state of the device from potential concurrent
> + * write accesses from userspace. The write operation requires an
> + * SPI write, then toggling of a GPIO, so the lock aims to protect
> + * the sanity of the entire sequence of operation.
> + */
> + struct mutex lock;
> +
> /*
> * DMA (thus cache coherency maintenance) requires the
> * transfer buffers to live in their own cache lines.
> @@ -101,9 +109,9 @@ static int dac7612_write_raw(struct iio_dev *iio_dev,
> if (val == priv->cache[chan->channel])
> return 0;
>
> - mutex_lock(&iio_dev->mlock);
> + mutex_lock(&priv->lock);
> ret = dac7612_cmd_single(priv, chan->channel, val);
> - mutex_unlock(&iio_dev->mlock);
> + mutex_unlock(&priv->lock);
>
> return ret;
> }
> @@ -145,6 +153,8 @@ static int dac7612_probe(struct spi_device *spi)
> iio_dev->num_channels = ARRAY_SIZE(priv->cache);
> iio_dev->name = spi_get_device_id(spi)->name;
>
> + mutex_init(&priv->lock);
> +
> for (i = 0; i < ARRAY_SIZE(priv->cache); i++) {
> ret = dac7612_cmd_single(priv, i, 0);
> if (ret)
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2020-09-16 17:59 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2020-08-26 6:40 [PATCH] iio: dac: ti-dac7612: Replace indio_dev->mlock with own device lock Alexandru Ardelean
2020-08-29 15:47 ` Jonathan Cameron
2020-09-16 9:25 ` [PATCH v2] " Alexandru Ardelean
2020-09-16 17:56 ` Jonathan Cameron
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