On 22 March 2017 19:22:20 GMT+00:00, Jonathan Cameron <ji...@kernel.org> wrote:
>On 22/03/17 16:20, 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.
>>
>> In the driver, buf_lock protects both the adis16060_spi_write() and
>> adis16060_spi_read() functions and both are always called in
>> pair. First write, then read. Refactor the code to have
>> one single function adis16060_spi_write_than_read() and remove
>> the use of mlock as adis16060_read_raw() does not require an
>> iio_dev->mlock for reads.
>I'll slightly modify this description. The key thing is
>that after the above change to have a unified read then write
>there is no longer any need for mlock to protect these
>read, update, write cycles.
>>
>> Signed-off-by: simran singhal <singhalsimr...@gmail.com>
>Applied to the togreg branch of iio.git and pushed out as testing
>for the autobuilders to play with it.
>
>I slightly modified the title as well. It's useful to be a little
>more specific than staging, so I added iio: after that.
Another example of how the tests that 0day is doing are way better than my
tired eyes at the end of a day...
>
>Thanks,
>
>Jonathan
>> ---
>>
>> v8:
>> -change subject
>> -change commit message
>> v7:
>> -Change subject
>> -Remove lock from read_raw instead from
>> function adis16060_spi_write_than_read().
>> v6:
>> -Change commit message
>> -Remove nested lock
>> v5:
>> -Rename val in adis16060_spi_write_than_read() to conf.
>> -Rename val2 in adis16060_spi_write_than_read() to val.
>> -Corrected Checkpatch issues.
>> -Removed goto from adis16060_read_raw().
>> v4:
>> -Refactored code
>> -change commit subject
>> -change commit message
>> v3:
>> -Removed new lock to reuse the existing lock
>> v2:
>> -Fixed compilation error
>>
>> drivers/staging/iio/gyro/adis16060_core.c | 33
>++++++++-----------------------
>> 1 file changed, 8 insertions(+), 25 deletions(-)
>>
>> diff --git a/drivers/staging/iio/gyro/adis16060_core.c
>b/drivers/staging/iio/gyro/adis16060_core.c
>> index c9d46e7..e96fce5 100644
>> --- a/drivers/staging/iio/gyro/adis16060_core.c
>> +++ b/drivers/staging/iio/gyro/adis16060_core.c
>> @@ -40,25 +40,18 @@ 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)
Not unlocking buf_lock in this path. I will fix up later....
Jonathan
>> + return ret;
>>
>> ret = spi_read(st->us_r, st->buf, 3);
>>
>> @@ -86,17 +79,11 @@ 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);
>> - ret = adis16060_spi_write(indio_dev, chan->address);
>> + ret = adis16060_spi_write_than_read(indio_dev,
>> + chan->address, &tval);
>> 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 +97,6 @@ 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 = {
>>
>
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Sent from my Android device with K-9 Mail. Please excuse my brevity.
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