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? 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
