On Sat, Mar 18, 2017 at 11:51 PM, Jonathan Cameron <jic23@xxxxxxxxxx> wrote: > On 18/03/17 17:34, SIMRAN SINGHAL wrote: >> On Thu, Mar 16, 2017 at 3:23 AM, Jonathan Cameron <jic23@xxxxxxxxxx> wrote: >>> On 13/03/17 19:53, Alison Schofield wrote: >>>> On Mon, Mar 13, 2017 at 10:01:07PM +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. >>>>> >>>>> Fix some coding style issues related to white space also. >>>>> >>>>> Signed-off-by: simran singhal <singhalsimran0@xxxxxxxxx> >>>>> --- >>>>> >>>>> v2: >>>>> -Removed new lock to reuse the existing lock >>>> Simran, >>>> >>>> The good news is that you have 2 patches that have similar >>>> challenges! I'll suggest picking one, drive it to completion, >>>> then do the other. >>>> >>>> This has the nested locking issue that Lars warned about. >>>> Need to refactor to avoid. Check back on his review comments. >>>> >>>> I suggest dropping those whitespace changes - they appear >>>> out of place in this patch since you are no longer actually >>>> touching those lines of code. >>>> >>>> alisons >>> Also missing a mutex_init, though that may well become irrelevant >>> with refactoring as suggested. >> >> Jonathon, what I found by looking at the codes of other drivers is that >> we have to use mutex_init in probe function only. >> >> Is this correct? > Yes, it only needs initializing once. >> So, no need of using mutex_init here as the function is not a probe function. Thanks Simran >> And this patch also suggest the same:- >> https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git/commit/?h=testing&id=388c8f18ff29fe95dbf72cb0a1bd8fbcd6f52f8f >> >>>> >>>> >>>>> >>>>> drivers/staging/iio/meter/ade7753.c | 12 ++++++------ >>>>> 1 file changed, 6 insertions(+), 6 deletions(-) >>>>> >>>>> diff --git a/drivers/staging/iio/meter/ade7753.c b/drivers/staging/iio/meter/ade7753.c >>>>> index dfd8b71..d88eaa3 100644 >>>>> --- a/drivers/staging/iio/meter/ade7753.c >>>>> +++ b/drivers/staging/iio/meter/ade7753.c >>>>> @@ -83,10 +83,10 @@ >>>>> * @buf_lock: mutex to protect tx and rx >>>>> **/ >>>>> struct ade7753_state { >>>>> - struct spi_device *us; >>>>> - struct mutex buf_lock; >>>>> - u8 tx[ADE7753_MAX_TX] ____cacheline_aligned; >>>>> - u8 rx[ADE7753_MAX_RX]; >>>>> + struct spi_device *us; >>>>> + struct mutex buf_lock; >>>>> + u8 tx[ADE7753_MAX_TX] ____cacheline_aligned; >>>>> + u8 rx[ADE7753_MAX_RX]; >>>>> }; >>>>> >>>>> static int ade7753_spi_write_reg_8(struct device *dev, >>>>> @@ -484,7 +484,7 @@ static ssize_t ade7753_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) >>>>> @@ -505,7 +505,7 @@ static ssize_t ade7753_write_frequency(struct device *dev, >>>>> ret = ade7753_spi_write_reg_16(dev, ADE7753_MODE, reg); >>>>> >>>>> out: >>>>> - mutex_unlock(&indio_dev->mlock); >>>>> + mutex_unlock(&st->buf_lock); >>>>> >>>>> return ret ? ret : len; >>>>> } >>>>> -- >>>>> 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@xxxxxxxxxxxxxxxx. >>>>> To post to this group, send email to outreachy-kernel@xxxxxxxxxxxxxxxx. >>>>> To view this discussion on the web visit https://groups.google.com/d/msgid/outreachy-kernel/20170313163107.GA31496%40singhal-Inspiron-5558. >>>>> For more options, visit https://groups.google.com/d/optout. >>>> -- >>>> To unsubscribe from this list: send the line "unsubscribe linux-iio" in >>>> the body of a message to majordomo@xxxxxxxxxxxxxxx >>>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>>> >>> > -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
