[PATCH v6] staging: Use buf_lock instead of mlock and Refactor code

[PATCH v6] staging: Use buf_lock instead of mlock and Refactor code

[simran singhal]

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 buf_lock in the devices global data.

As buf_lock protects both the adis16060_spi_write() and
adis16060_spi_read() functions and both are always called in
pair. First write, then read. Thus, refactor the code to have
one single function adis16060_spi_write_than_read() which is
protected by the existing buf_lock.

Removed nested locks as the function adis16060_read_raw call
a lock on &st->buf_lock and then calls the function
adis16060_spi_write which again tries to get hold
of the same lock.

Signed-off-by: simran singhal <singhalsimran0@gmail.com>
---

 v6:
   -Change commit message
   -Remove nested lock

 drivers/staging/iio/gyro/adis16060_core.c | 40 ++++++++++---------------------
 1 file changed, 13 insertions(+), 27 deletions(-)

diff --git a/drivers/staging/iio/gyro/adis16060_core.c b/drivers/staging/iio/gyro/adis16060_core.c
index c9d46e7..1c6de46 100644
--- a/drivers/staging/iio/gyro/adis16060_core.c
+++ b/drivers/staging/iio/gyro/adis16060_core.c
@@ -40,25 +40,17 @@ struct adis16060_state {
 
 static struct iio_dev *adis16060_iio_dev;
 
-static int adis16060_spi_write(struct iio_dev *indio_dev, u8 val)
+static int adis16060_spi_write_than_read(struct iio_dev *indio_dev,
+					 u8 conf, u16 *val)
 {
 	int ret;
 	struct adis16060_state *st = iio_priv(indio_dev);
 
-	mutex_lock(&st->buf_lock);
-	st->buf[2] = val; /* The last 8 bits clocked in are latched */
+	st->buf[2] = conf; /* The last 8 bits clocked in are latched */
 	ret = spi_write(st->us_w, st->buf, 3);
-	mutex_unlock(&st->buf_lock);
-
-	return ret;
-}
-
-static int adis16060_spi_read(struct iio_dev *indio_dev, u16 *val)
-{
-	int ret;
-	struct adis16060_state *st = iio_priv(indio_dev);
 
-	mutex_lock(&st->buf_lock);
+	if (ret < 0)
+		return ret;
 
 	ret = spi_read(st->us_r, st->buf, 3);
 
@@ -69,8 +61,8 @@ static int adis16060_spi_read(struct iio_dev *indio_dev, u16 *val)
 	 */
 	if (!ret)
 		*val = ((st->buf[0] & 0x3) << 12) |
-			(st->buf[1] << 4) |
-			((st->buf[2] >> 4) & 0xF);
+			 (st->buf[1] << 4) |
+			 ((st->buf[2] >> 4) & 0xF);
 	mutex_unlock(&st->buf_lock);
 
 	return ret;
@@ -83,20 +75,18 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
 {
 	u16 tval = 0;
 	int ret;
+	struct adis16060_state *st = iio_priv(indio_dev);
 
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 		/* Take the iio_dev status lock */
-		mutex_lock(&indio_dev->mlock);
-		ret = adis16060_spi_write(indio_dev, chan->address);
+		mutex_lock(&st->buf_lock);
+		ret = adis16060_spi_write_than_read(indio_dev,
+						    chan->address, &tval);
+		mutex_unlock(&st->buf_lock);
 		if (ret < 0)
-			goto out_unlock;
+			return ret;
 
-		ret = adis16060_spi_read(indio_dev, &tval);
-		if (ret < 0)
-			goto out_unlock;
-
-		mutex_unlock(&indio_dev->mlock);
 		*val = tval;
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_OFFSET:
@@ -110,10 +100,6 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
 	}
 
 	return -EINVAL;
-
-out_unlock:
-	mutex_unlock(&indio_dev->mlock);
-	return ret;
 }
 
 static const struct iio_info adis16060_info = {
-- 
2.7.4

Re: [Outreachy kernel] [PATCH v6] staging: Use buf_lock instead of mlock and Refactor code

[Alison Schofield]

On Mon, Mar 20, 2017 at 01:36:21AM +0530, simran singhal wrote:

Hi Simran,  

I going to ask for a v7 without looking at the code ;)
Subject line needs subsystem and driver.
Subject and log message can be improved.

> 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 buf_lock in the devices global data.
           ^^^^^^^^^^^ this was not done
> 
> As buf_lock protects both the adis16060_spi_write() and
> adis16060_spi_read() functions and both are always called in
> pair. First write, then read. Thus, refactor the code to have
> one single function adis16060_spi_write_than_read() which is
> protected by the existing buf_lock.
This was done.  So, you were able to obsolete the need for mlock
by creating the paired function.

> 
> Removed nested locks as the function adis16060_read_raw call
> a lock on &st->buf_lock and then calls the function
> adis16060_spi_write which again tries to get hold
> of the same lock.
^^^^ this was not done.  Yes, you avoided nested locks through
proper coding, but we don't want to give the impression in the
log message that there was a pre-existing nested lock issue.

I did checkpatch & compile it...but looked no further yet.

alisons
> 
> Signed-off-by: simran singhal <singhalsimran0@gmail.com>
> ---
> 
>  v6:
>    -Change commit message
>    -Remove nested lock
> 
>  drivers/staging/iio/gyro/adis16060_core.c | 40 ++++++++++---------------------
>  1 file changed, 13 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/staging/iio/gyro/adis16060_core.c b/drivers/staging/iio/gyro/adis16060_core.c
> index c9d46e7..1c6de46 100644
> --- a/drivers/staging/iio/gyro/adis16060_core.c
> +++ b/drivers/staging/iio/gyro/adis16060_core.c
> @@ -40,25 +40,17 @@ struct adis16060_state {
>  
>  static struct iio_dev *adis16060_iio_dev;
>  
> -static int adis16060_spi_write(struct iio_dev *indio_dev, u8 val)
> +static int adis16060_spi_write_than_read(struct iio_dev *indio_dev,
> +					 u8 conf, u16 *val)
>  {
>  	int ret;
>  	struct adis16060_state *st = iio_priv(indio_dev);
>  
> -	mutex_lock(&st->buf_lock);
> -	st->buf[2] = val; /* The last 8 bits clocked in are latched */
> +	st->buf[2] = conf; /* The last 8 bits clocked in are latched */
>  	ret = spi_write(st->us_w, st->buf, 3);
> -	mutex_unlock(&st->buf_lock);
> -
> -	return ret;
> -}
> -
> -static int adis16060_spi_read(struct iio_dev *indio_dev, u16 *val)
> -{
> -	int ret;
> -	struct adis16060_state *st = iio_priv(indio_dev);
>  
> -	mutex_lock(&st->buf_lock);
> +	if (ret < 0)
> +		return ret;
>  
>  	ret = spi_read(st->us_r, st->buf, 3);
>  
> @@ -69,8 +61,8 @@ static int adis16060_spi_read(struct iio_dev *indio_dev, u16 *val)
>  	 */
>  	if (!ret)
>  		*val = ((st->buf[0] & 0x3) << 12) |
> -			(st->buf[1] << 4) |
> -			((st->buf[2] >> 4) & 0xF);
> +			 (st->buf[1] << 4) |
> +			 ((st->buf[2] >> 4) & 0xF);
>  	mutex_unlock(&st->buf_lock);
>  
>  	return ret;
> @@ -83,20 +75,18 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
>  {
>  	u16 tval = 0;
>  	int ret;
> +	struct adis16060_state *st = iio_priv(indio_dev);
>  
>  	switch (mask) {
>  	case IIO_CHAN_INFO_RAW:
>  		/* Take the iio_dev status lock */
> -		mutex_lock(&indio_dev->mlock);
> -		ret = adis16060_spi_write(indio_dev, chan->address);
> +		mutex_lock(&st->buf_lock);
> +		ret = adis16060_spi_write_than_read(indio_dev,
> +						    chan->address, &tval);
> +		mutex_unlock(&st->buf_lock);
>  		if (ret < 0)
> -			goto out_unlock;
> +			return ret;
>  
> -		ret = adis16060_spi_read(indio_dev, &tval);
> -		if (ret < 0)
> -			goto out_unlock;
> -
> -		mutex_unlock(&indio_dev->mlock);
>  		*val = tval;
>  		return IIO_VAL_INT;
>  	case IIO_CHAN_INFO_OFFSET:
> @@ -110,10 +100,6 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
>  	}
>  
>  	return -EINVAL;
> -
> -out_unlock:
> -	mutex_unlock(&indio_dev->mlock);
> -	return ret;
>  }
>  
>  static const struct iio_info adis16060_info = {
> -- 
> 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 outreachy-kernel+unsubscribe@googlegroups.com.
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> For more options, visit https://groups.google.com/d/optout.

Re: [Outreachy kernel] [PATCH v6] staging: Use buf_lock instead of mlock and Refactor code

[SIMRAN SINGHAL]

On Tue, Mar 21, 2017 at 10:18 PM, Alison Schofield <amsfield22@gmail.com> wrote:
> On Mon, Mar 20, 2017 at 01:36:21AM +0530, simran singhal wrote:
>
> Hi Simran,
>
> I going to ask for a v7 without looking at the code ;)
> Subject line needs subsystem and driver.
> Subject and log message can be improved.

Hi Alison,
I have already sent v7 with changed subject.

>
>> 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 buf_lock in the devices global data.
>            ^^^^^^^^^^^ this was not done
>>
>> As buf_lock protects both the adis16060_spi_write() and
>> adis16060_spi_read() functions and both are always called in
>> pair. First write, then read. Thus, refactor the code to have
>> one single function adis16060_spi_write_than_read() which is
>> protected by the existing buf_lock.
> This was done.  So, you were able to obsolete the need for mlock
> by creating the paired function.
>
>>
>> Removed nested locks as the function adis16060_read_raw call
>> a lock on &st->buf_lock and then calls the function
>> adis16060_spi_write which again tries to get hold
>> of the same lock.
> ^^^^ this was not done.  Yes, you avoided nested locks through
> proper coding, but we don't want to give the impression in the
> log message that there was a pre-existing nested lock issue.
>
> I did checkpatch & compile it...but looked no further yet.
>
> alisons
>>
>> Signed-off-by: simran singhal <singhalsimran0@gmail.com>
>> ---
>>
>>  v6:
>>    -Change commit message
>>    -Remove nested lock
>>
>>  drivers/staging/iio/gyro/adis16060_core.c | 40 ++++++++++---------------------
>>  1 file changed, 13 insertions(+), 27 deletions(-)
>>
>> diff --git a/drivers/staging/iio/gyro/adis16060_core.c b/drivers/staging/iio/gyro/adis16060_core.c
>> index c9d46e7..1c6de46 100644
>> --- a/drivers/staging/iio/gyro/adis16060_core.c
>> +++ b/drivers/staging/iio/gyro/adis16060_core.c
>> @@ -40,25 +40,17 @@ struct adis16060_state {
>>
>>  static struct iio_dev *adis16060_iio_dev;
>>
>> -static int adis16060_spi_write(struct iio_dev *indio_dev, u8 val)
>> +static int adis16060_spi_write_than_read(struct iio_dev *indio_dev,
>> +                                      u8 conf, u16 *val)
>>  {
>>       int ret;
>>       struct adis16060_state *st = iio_priv(indio_dev);
>>
>> -     mutex_lock(&st->buf_lock);
>> -     st->buf[2] = val; /* The last 8 bits clocked in are latched */
>> +     st->buf[2] = conf; /* The last 8 bits clocked in are latched */
>>       ret = spi_write(st->us_w, st->buf, 3);
>> -     mutex_unlock(&st->buf_lock);
>> -
>> -     return ret;
>> -}
>> -
>> -static int adis16060_spi_read(struct iio_dev *indio_dev, u16 *val)
>> -{
>> -     int ret;
>> -     struct adis16060_state *st = iio_priv(indio_dev);
>>
>> -     mutex_lock(&st->buf_lock);
>> +     if (ret < 0)
>> +             return ret;
>>
>>       ret = spi_read(st->us_r, st->buf, 3);
>>
>> @@ -69,8 +61,8 @@ static int adis16060_spi_read(struct iio_dev *indio_dev, u16 *val)
>>        */
>>       if (!ret)
>>               *val = ((st->buf[0] & 0x3) << 12) |
>> -                     (st->buf[1] << 4) |
>> -                     ((st->buf[2] >> 4) & 0xF);
>> +                      (st->buf[1] << 4) |
>> +                      ((st->buf[2] >> 4) & 0xF);
>>       mutex_unlock(&st->buf_lock);
>>
>>       return ret;
>> @@ -83,20 +75,18 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
>>  {
>>       u16 tval = 0;
>>       int ret;
>> +     struct adis16060_state *st = iio_priv(indio_dev);
>>
>>       switch (mask) {
>>       case IIO_CHAN_INFO_RAW:
>>               /* Take the iio_dev status lock */
>> -             mutex_lock(&indio_dev->mlock);
>> -             ret = adis16060_spi_write(indio_dev, chan->address);
>> +             mutex_lock(&st->buf_lock);
>> +             ret = adis16060_spi_write_than_read(indio_dev,
>> +                                                 chan->address, &tval);
>> +             mutex_unlock(&st->buf_lock);
>>               if (ret < 0)
>> -                     goto out_unlock;
>> +                     return ret;
>>
>> -             ret = adis16060_spi_read(indio_dev, &tval);
>> -             if (ret < 0)
>> -                     goto out_unlock;
>> -
>> -             mutex_unlock(&indio_dev->mlock);
>>               *val = tval;
>>               return IIO_VAL_INT;
>>       case IIO_CHAN_INFO_OFFSET:
>> @@ -110,10 +100,6 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
>>       }
>>
>>       return -EINVAL;
>> -
>> -out_unlock:
>> -     mutex_unlock(&indio_dev->mlock);
>> -     return ret;
>>  }
>>
>>  static const struct iio_info adis16060_info = {
>> --
>> 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 outreachy-kernel+unsubscribe@googlegroups.com.
>> To post to this group, send email to outreachy-kernel@googlegroups.com.
>> To view this discussion on the web visit https://groups.google.com/d/msgid/outreachy-kernel/20170319200621.GA21295%40singhal-Inspiron-5558.
>> For more options, visit https://groups.google.com/d/optout.

Re: [Outreachy kernel] [PATCH v6] staging: Use buf_lock instead of mlock and Refactor code

[Alison Schofield]

On Tue, Mar 21, 2017 at 10:34:01PM +0530, SIMRAN SINGHAL wrote:
> On Tue, Mar 21, 2017 at 10:18 PM, Alison Schofield <amsfield22@gmail.com> wrote:
> > On Mon, Mar 20, 2017 at 01:36:21AM +0530, simran singhal wrote:
> >
> > Hi Simran,
> >
> > I going to ask for a v7 without looking at the code ;)
> > Subject line needs subsystem and driver.
> > Subject and log message can be improved.
> 
> Hi Alison,
> I have already sent v7 with changed subject.

Simran,
I see v7.  Needs subsystem (iio) and to nitpick, driver name
is "adis16060" ;) Other comments still apply. 
Please append all version histories below the --- for review.
v7:
v6:
.
.
v2: 
thanks,
alisons
> 
> >
> >> 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 buf_lock in the devices global data.
> >            ^^^^^^^^^^^ this was not done
> >>
> >> As buf_lock protects both the adis16060_spi_write() and
> >> adis16060_spi_read() functions and both are always called in
> >> pair. First write, then read. Thus, refactor the code to have
> >> one single function adis16060_spi_write_than_read() which is
> >> protected by the existing buf_lock.
> > This was done.  So, you were able to obsolete the need for mlock
> > by creating the paired function.
> >
> >>
> >> Removed nested locks as the function adis16060_read_raw call
> >> a lock on &st->buf_lock and then calls the function
> >> adis16060_spi_write which again tries to get hold
> >> of the same lock.
> > ^^^^ this was not done.  Yes, you avoided nested locks through
> > proper coding, but we don't want to give the impression in the
> > log message that there was a pre-existing nested lock issue.
> >
> > I did checkpatch & compile it...but looked no further yet.
> >
> > alisons
> >>
> >> Signed-off-by: simran singhal <singhalsimran0@gmail.com>
> >> ---
> >>
> >>  v6:
> >>    -Change commit message
> >>    -Remove nested lock
> >>
> >>  drivers/staging/iio/gyro/adis16060_core.c | 40 ++++++++++---------------------
> >>  1 file changed, 13 insertions(+), 27 deletions(-)
> >>
> >> diff --git a/drivers/staging/iio/gyro/adis16060_core.c b/drivers/staging/iio/gyro/adis16060_core.c
> >> index c9d46e7..1c6de46 100644
> >> --- a/drivers/staging/iio/gyro/adis16060_core.c
> >> +++ b/drivers/staging/iio/gyro/adis16060_core.c
> >> @@ -40,25 +40,17 @@ struct adis16060_state {
> >>
> >>  static struct iio_dev *adis16060_iio_dev;
> >>
> >> -static int adis16060_spi_write(struct iio_dev *indio_dev, u8 val)
> >> +static int adis16060_spi_write_than_read(struct iio_dev *indio_dev,
> >> +                                      u8 conf, u16 *val)
> >>  {
> >>       int ret;
> >>       struct adis16060_state *st = iio_priv(indio_dev);
> >>
> >> -     mutex_lock(&st->buf_lock);
> >> -     st->buf[2] = val; /* The last 8 bits clocked in are latched */
> >> +     st->buf[2] = conf; /* The last 8 bits clocked in are latched */
> >>       ret = spi_write(st->us_w, st->buf, 3);
> >> -     mutex_unlock(&st->buf_lock);
> >> -
> >> -     return ret;
> >> -}
> >> -
> >> -static int adis16060_spi_read(struct iio_dev *indio_dev, u16 *val)
> >> -{
> >> -     int ret;
> >> -     struct adis16060_state *st = iio_priv(indio_dev);
> >>
> >> -     mutex_lock(&st->buf_lock);
> >> +     if (ret < 0)
> >> +             return ret;
> >>
> >>       ret = spi_read(st->us_r, st->buf, 3);
> >>
> >> @@ -69,8 +61,8 @@ static int adis16060_spi_read(struct iio_dev *indio_dev, u16 *val)
> >>        */
> >>       if (!ret)
> >>               *val = ((st->buf[0] & 0x3) << 12) |
> >> -                     (st->buf[1] << 4) |
> >> -                     ((st->buf[2] >> 4) & 0xF);
> >> +                      (st->buf[1] << 4) |
> >> +                      ((st->buf[2] >> 4) & 0xF);
> >>       mutex_unlock(&st->buf_lock);
> >>
> >>       return ret;
> >> @@ -83,20 +75,18 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
> >>  {
> >>       u16 tval = 0;
> >>       int ret;
> >> +     struct adis16060_state *st = iio_priv(indio_dev);
> >>
> >>       switch (mask) {
> >>       case IIO_CHAN_INFO_RAW:
> >>               /* Take the iio_dev status lock */
> >> -             mutex_lock(&indio_dev->mlock);
> >> -             ret = adis16060_spi_write(indio_dev, chan->address);
> >> +             mutex_lock(&st->buf_lock);
> >> +             ret = adis16060_spi_write_than_read(indio_dev,
> >> +                                                 chan->address, &tval);
> >> +             mutex_unlock(&st->buf_lock);
> >>               if (ret < 0)
> >> -                     goto out_unlock;
> >> +                     return ret;
> >>
> >> -             ret = adis16060_spi_read(indio_dev, &tval);
> >> -             if (ret < 0)
> >> -                     goto out_unlock;
> >> -
> >> -             mutex_unlock(&indio_dev->mlock);
> >>               *val = tval;
> >>               return IIO_VAL_INT;
> >>       case IIO_CHAN_INFO_OFFSET:
> >> @@ -110,10 +100,6 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
> >>       }
> >>
> >>       return -EINVAL;
> >> -
> >> -out_unlock:
> >> -     mutex_unlock(&indio_dev->mlock);
> >> -     return ret;
> >>  }
> >>
> >>  static const struct iio_info adis16060_info = {
> >> --
> >> 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 outreachy-kernel+unsubscribe@googlegroups.com.
> >> To post to this group, send email to outreachy-kernel@googlegroups.com.
> >> To view this discussion on the web visit https://groups.google.com/d/msgid/outreachy-kernel/20170319200621.GA21295%40singhal-Inspiron-5558.
> >> For more options, visit https://groups.google.com/d/optout.

Re: [Outreachy kernel] [PATCH v6] staging: Use buf_lock instead of mlock and Refactor code

[SIMRAN SINGHAL]

On Tue, Mar 21, 2017 at 10:18 PM, Alison Schofield <amsfield22@gmail.com> wrote:
> On Mon, Mar 20, 2017 at 01:36:21AM +0530, simran singhal wrote:
>
> Hi Simran,
>
> I going to ask for a v7 without looking at the code ;)
> Subject line needs subsystem and driver.
> Subject and log message can be improved.
>
>> 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 buf_lock in the devices global data.
>            ^^^^^^^^^^^ this was not done
>>
>> As buf_lock protects both the adis16060_spi_write() and
>> adis16060_spi_read() functions and both are always called in
>> pair. First write, then read. Thus, refactor the code to have
>> one single function adis16060_spi_write_than_read() which is
>> protected by the existing buf_lock.
> This was done.  So, you were able to obsolete the need for mlock
> by creating the paired function.

I am still using mlock but now locking it and performing both write and
read and than unlocking.

So, now have a single safe function.

>
>>
>> Removed nested locks as the function adis16060_read_raw call
>> a lock on &st->buf_lock and then calls the function
>> adis16060_spi_write which again tries to get hold
>> of the same lock.
> ^^^^ this was not done.  Yes, you avoided nested locks through
> proper coding, but we don't want to give the impression in the
> log message that there was a pre-existing nested lock issue.
>
> I did checkpatch & compile it...but looked no further yet.
>
> alisons
>>
>> Signed-off-by: simran singhal <singhalsimran0@gmail.com>
>> ---
>>
>>  v6:
>>    -Change commit message
>>    -Remove nested lock
>>
>>  drivers/staging/iio/gyro/adis16060_core.c | 40 ++++++++++---------------------
>>  1 file changed, 13 insertions(+), 27 deletions(-)
>>
>> diff --git a/drivers/staging/iio/gyro/adis16060_core.c b/drivers/staging/iio/gyro/adis16060_core.c
>> index c9d46e7..1c6de46 100644
>> --- a/drivers/staging/iio/gyro/adis16060_core.c
>> +++ b/drivers/staging/iio/gyro/adis16060_core.c
>> @@ -40,25 +40,17 @@ struct adis16060_state {
>>
>>  static struct iio_dev *adis16060_iio_dev;
>>
>> -static int adis16060_spi_write(struct iio_dev *indio_dev, u8 val)
>> +static int adis16060_spi_write_than_read(struct iio_dev *indio_dev,
>> +                                      u8 conf, u16 *val)
>>  {
>>       int ret;
>>       struct adis16060_state *st = iio_priv(indio_dev);
>>
>> -     mutex_lock(&st->buf_lock);
>> -     st->buf[2] = val; /* The last 8 bits clocked in are latched */
>> +     st->buf[2] = conf; /* The last 8 bits clocked in are latched */
>>       ret = spi_write(st->us_w, st->buf, 3);
>> -     mutex_unlock(&st->buf_lock);
>> -
>> -     return ret;
>> -}
>> -
>> -static int adis16060_spi_read(struct iio_dev *indio_dev, u16 *val)
>> -{
>> -     int ret;
>> -     struct adis16060_state *st = iio_priv(indio_dev);
>>
>> -     mutex_lock(&st->buf_lock);
>> +     if (ret < 0)
>> +             return ret;
>>
>>       ret = spi_read(st->us_r, st->buf, 3);
>>
>> @@ -69,8 +61,8 @@ static int adis16060_spi_read(struct iio_dev *indio_dev, u16 *val)
>>        */
>>       if (!ret)
>>               *val = ((st->buf[0] & 0x3) << 12) |
>> -                     (st->buf[1] << 4) |
>> -                     ((st->buf[2] >> 4) & 0xF);
>> +                      (st->buf[1] << 4) |
>> +                      ((st->buf[2] >> 4) & 0xF);
>>       mutex_unlock(&st->buf_lock);
>>
>>       return ret;
>> @@ -83,20 +75,18 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
>>  {
>>       u16 tval = 0;
>>       int ret;
>> +     struct adis16060_state *st = iio_priv(indio_dev);
>>
>>       switch (mask) {
>>       case IIO_CHAN_INFO_RAW:
>>               /* Take the iio_dev status lock */
>> -             mutex_lock(&indio_dev->mlock);
>> -             ret = adis16060_spi_write(indio_dev, chan->address);
>> +             mutex_lock(&st->buf_lock);
>> +             ret = adis16060_spi_write_than_read(indio_dev,
>> +                                                 chan->address, &tval);
>> +             mutex_unlock(&st->buf_lock);
>>               if (ret < 0)
>> -                     goto out_unlock;
>> +                     return ret;
>>
>> -             ret = adis16060_spi_read(indio_dev, &tval);
>> -             if (ret < 0)
>> -                     goto out_unlock;
>> -
>> -             mutex_unlock(&indio_dev->mlock);
>>               *val = tval;
>>               return IIO_VAL_INT;
>>       case IIO_CHAN_INFO_OFFSET:
>> @@ -110,10 +100,6 @@ static int adis16060_read_raw(struct iio_dev *indio_dev,
>>       }
>>
>>       return -EINVAL;
>> -
>> -out_unlock:
>> -     mutex_unlock(&indio_dev->mlock);
>> -     return ret;
>>  }
>>
>>  static const struct iio_info adis16060_info = {
>> --
>> 2.7.4
>>
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