2017-03-12 13:11:04

by Simran Singhal

[permalink] [raw]
Subject: [PATCH] staging: adis16060_core: Use private driver lock instead of mlock

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 lock in the devices global data.

Signed-off-by: simran singhal <[email protected]>
---
drivers/staging/iio/gyro/adis16060_core.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/iio/gyro/adis16060_core.c b/drivers/staging/iio/gyro/adis16060_core.c
index c9d46e7..90a3a18 100644
--- a/drivers/staging/iio/gyro/adis16060_core.c
+++ b/drivers/staging/iio/gyro/adis16060_core.c
@@ -29,11 +29,13 @@
* @us_r: actual spi_device to read back data
* @buf: transmit or receive buffer
* @buf_lock: mutex to protect tx and rx
+ * @lock: protect sensor state
**/
struct adis16060_state {
struct spi_device *us_w;
struct spi_device *us_r;
struct mutex buf_lock;
+ struct mutex lock; /* protect sensor state */

u8 buf[3] ____cacheline_aligned;
};
@@ -87,7 +89,7 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
switch (mask) {
case IIO_CHAN_INFO_RAW:
/* Take the iio_dev status lock */
- mutex_lock(&indio_dev->mlock);
+ mutex_lock(&st->lock);
ret = adis16060_spi_write(indio_dev, chan->address);
if (ret < 0)
goto out_unlock;
@@ -96,7 +98,7 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
if (ret < 0)
goto out_unlock;

- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&st->lock);
*val = tval;
return IIO_VAL_INT;
case IIO_CHAN_INFO_OFFSET:
@@ -112,7 +114,7 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
return -EINVAL;

out_unlock:
- mutex_unlock(&indio_dev->mlock);
+ mutex_unlock(&st->lock);
return ret;
}

--
2.7.4


2017-03-12 16:24:06

by Alison Schofield

[permalink] [raw]
Subject: Re: [Outreachy kernel] [PATCH] staging: adis16060_core: Use private driver lock instead of mlock

On Sun, Mar 12, 2017 at 06:40:52PM +0530, simran 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 lock in the devices global data.
>
> Signed-off-by: simran singhal <[email protected]>

Hi Simran,
These are now IIO tasks for this round of Outreachy. Please
follow the directions on the IIO task page w.r.t. claiming,
sending, and all.
Thanks,
alisons

> ---
> drivers/staging/iio/gyro/adis16060_core.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/staging/iio/gyro/adis16060_core.c b/drivers/staging/iio/gyro/adis16060_core.c
> index c9d46e7..90a3a18 100644
> --- a/drivers/staging/iio/gyro/adis16060_core.c
> +++ b/drivers/staging/iio/gyro/adis16060_core.c
> @@ -29,11 +29,13 @@
> * @us_r: actual spi_device to read back data
> * @buf: transmit or receive buffer
> * @buf_lock: mutex to protect tx and rx
> + * @lock: protect sensor state
> **/
> struct adis16060_state {
> struct spi_device *us_w;
> struct spi_device *us_r;
> struct mutex buf_lock;
> + struct mutex lock; /* protect sensor state */
>
> u8 buf[3] ____cacheline_aligned;
> };
> @@ -87,7 +89,7 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
> switch (mask) {
> case IIO_CHAN_INFO_RAW:
> /* Take the iio_dev status lock */
> - mutex_lock(&indio_dev->mlock);
> + mutex_lock(&st->lock);
> ret = adis16060_spi_write(indio_dev, chan->address);
> if (ret < 0)
> goto out_unlock;
> @@ -96,7 +98,7 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
> if (ret < 0)
> goto out_unlock;
>
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&st->lock);
> *val = tval;
> return IIO_VAL_INT;
> case IIO_CHAN_INFO_OFFSET:
> @@ -112,7 +114,7 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
> return -EINVAL;
>
> out_unlock:
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&st->lock);
> return ret;
> }
>
> --
> 2.7.4
>
> --
> You received this message because you are subscribed to the Google Groups "outreachy-kernel" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
> To post to this group, send email to [email protected].
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> For more options, visit https://groups.google.com/d/optout.

2017-03-12 18:31:35

by Alison Schofield

[permalink] [raw]
Subject: Re: [Outreachy kernel] [PATCH] staging: adis16060_core: Use private driver lock instead of mlock

On Sun, Mar 12, 2017 at 06:40:52PM +0530, simran 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 lock in the devices global data.
>
> Signed-off-by: simran singhal <[email protected]>

This does not compile.
alisons

> ---
> drivers/staging/iio/gyro/adis16060_core.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/staging/iio/gyro/adis16060_core.c b/drivers/staging/iio/gyro/adis16060_core.c
> index c9d46e7..90a3a18 100644
> --- a/drivers/staging/iio/gyro/adis16060_core.c
> +++ b/drivers/staging/iio/gyro/adis16060_core.c
> @@ -29,11 +29,13 @@
> * @us_r: actual spi_device to read back data
> * @buf: transmit or receive buffer
> * @buf_lock: mutex to protect tx and rx
> + * @lock: protect sensor state
> **/
> struct adis16060_state {
> struct spi_device *us_w;
> struct spi_device *us_r;
> struct mutex buf_lock;
> + struct mutex lock; /* protect sensor state */
>
> u8 buf[3] ____cacheline_aligned;
> };
> @@ -87,7 +89,7 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
> switch (mask) {
> case IIO_CHAN_INFO_RAW:
> /* Take the iio_dev status lock */
> - mutex_lock(&indio_dev->mlock);
> + mutex_lock(&st->lock);
> ret = adis16060_spi_write(indio_dev, chan->address);
> if (ret < 0)
> goto out_unlock;
> @@ -96,7 +98,7 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
> if (ret < 0)
> goto out_unlock;
>
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&st->lock);
> *val = tval;
> return IIO_VAL_INT;
> case IIO_CHAN_INFO_OFFSET:
> @@ -112,7 +114,7 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
> return -EINVAL;
>
> out_unlock:
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&st->lock);
> return ret;
> }
>
> --
> 2.7.4
>
> --
> You received this message because you are subscribed to the Google Groups "outreachy-kernel" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
> To post to this group, send email to [email protected].
> To view this discussion on the web visit https://groups.google.com/d/msgid/outreachy-kernel/20170312131052.GA21816%40singhal-Inspiron-5558.
> For more options, visit https://groups.google.com/d/optout.

2017-03-13 12:29:45

by Simran Singhal

[permalink] [raw]
Subject: Re: [Outreachy kernel] [PATCH] staging: adis16060_core: Use private driver lock instead of mlock

On Mon, Mar 13, 2017 at 12:01 AM, Alison Schofield <[email protected]> wrote:
> On Sun, Mar 12, 2017 at 06:40:52PM +0530, simran 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 lock in the devices global data.
>>
>> Signed-off-by: simran singhal <[email protected]>
>
> This does not compile.
> alisons
>
Alison, this is compiling fine for me.
I tried it again using:
$make clean
$make allyesconfig
$make drivers/staging/iio/gyro/adis16060_core.o

>> ---
>> drivers/staging/iio/gyro/adis16060_core.c | 8 +++++---
>> 1 file changed, 5 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/staging/iio/gyro/adis16060_core.c b/drivers/staging/iio/gyro/adis16060_core.c
>> index c9d46e7..90a3a18 100644
>> --- a/drivers/staging/iio/gyro/adis16060_core.c
>> +++ b/drivers/staging/iio/gyro/adis16060_core.c
>> @@ -29,11 +29,13 @@
>> * @us_r: actual spi_device to read back data
>> * @buf: transmit or receive buffer
>> * @buf_lock: mutex to protect tx and rx
>> + * @lock: protect sensor state
>> **/
>> struct adis16060_state {
>> struct spi_device *us_w;
>> struct spi_device *us_r;
>> struct mutex buf_lock;
>> + struct mutex lock; /* protect sensor state */
>>
>> u8 buf[3] ____cacheline_aligned;
>> };
>> @@ -87,7 +89,7 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
>> switch (mask) {
>> case IIO_CHAN_INFO_RAW:
>> /* Take the iio_dev status lock */
>> - mutex_lock(&indio_dev->mlock);
>> + mutex_lock(&st->lock);
>> ret = adis16060_spi_write(indio_dev, chan->address);
>> if (ret < 0)
>> goto out_unlock;
>> @@ -96,7 +98,7 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
>> if (ret < 0)
>> goto out_unlock;
>>
>> - mutex_unlock(&indio_dev->mlock);
>> + mutex_unlock(&st->lock);
>> *val = tval;
>> return IIO_VAL_INT;
>> case IIO_CHAN_INFO_OFFSET:
>> @@ -112,7 +114,7 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
>> return -EINVAL;
>>
>> out_unlock:
>> - mutex_unlock(&indio_dev->mlock);
>> + mutex_unlock(&st->lock);
>> return ret;
>> }
>>
>> --
>> 2.7.4
>>
>> --
>> You received this message because you are subscribed to the Google Groups "outreachy-kernel" group.
>> To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
>> To post to this group, send email to [email protected].
>> To view this discussion on the web visit https://groups.google.com/d/msgid/outreachy-kernel/20170312131052.GA21816%40singhal-Inspiron-5558.
>> For more options, visit https://groups.google.com/d/optout.

2017-03-13 12:32:02

by Lars-Peter Clausen

[permalink] [raw]
Subject: Re: [PATCH] staging: adis16060_core: Use private driver lock instead of mlock

On 03/12/2017 02:10 PM, simran 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 lock in the devices global data.
>
> Signed-off-by: simran singhal <[email protected]>
> ---
> drivers/staging/iio/gyro/adis16060_core.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/staging/iio/gyro/adis16060_core.c b/drivers/staging/iio/gyro/adis16060_core.c
> index c9d46e7..90a3a18 100644
> --- a/drivers/staging/iio/gyro/adis16060_core.c
> +++ b/drivers/staging/iio/gyro/adis16060_core.c
> @@ -29,11 +29,13 @@
> * @us_r: actual spi_device to read back data
> * @buf: transmit or receive buffer
> * @buf_lock: mutex to protect tx and rx
> + * @lock: protect sensor state
> **/
> struct adis16060_state {
> struct spi_device *us_w;
> struct spi_device *us_r;
> struct mutex buf_lock;
> + struct mutex lock; /* protect sensor state */

There should be no need to have two locks here. One should be enough. The
buf_lock protects both the adis16060_spi_write() and adis16060_spi_read()
functions. But both are always called in a pair. First write, then read. You
can refactor the code to have one single function
adis16060_spi_write_than_read() which is protected by the existing buf_lock.


>
> u8 buf[3] ____cacheline_aligned;
> };
> @@ -87,7 +89,7 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
> switch (mask) {
> case IIO_CHAN_INFO_RAW:
> /* Take the iio_dev status lock */
> - mutex_lock(&indio_dev->mlock);
> + mutex_lock(&st->lock);
> ret = adis16060_spi_write(indio_dev, chan->address);
> if (ret < 0)
> goto out_unlock;
> @@ -96,7 +98,7 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
> if (ret < 0)
> goto out_unlock;
>
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&st->lock);
> *val = tval;
> return IIO_VAL_INT;
> case IIO_CHAN_INFO_OFFSET:
> @@ -112,7 +114,7 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
> return -EINVAL;
>
> out_unlock:
> - mutex_unlock(&indio_dev->mlock);
> + mutex_unlock(&st->lock);
> return ret;
> }
>
>