* [PATCH v6] staging: Use buf_lock instead of mlock and Refactor code @ 2017-03-19 20:06 simran singhal 2017-03-21 16:48 ` [Outreachy kernel] " Alison Schofield 0 siblings, 1 reply; 5+ messages in thread From: simran singhal @ 2017-03-19 20:06 UTC (permalink / raw) To: lars Cc: Michael.Hennerich, jic23, Hartmut Knaack, Peter Meerwald-Stadler, Greg Kroah-Hartman, linux-iio, devel, linux-kernel, outreachy-kernel 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 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [Outreachy kernel] [PATCH v6] staging: Use buf_lock instead of mlock and Refactor code 2017-03-19 20:06 [PATCH v6] staging: Use buf_lock instead of mlock and Refactor code simran singhal @ 2017-03-21 16:48 ` Alison Schofield 2017-03-21 17:04 ` SIMRAN SINGHAL 2017-03-21 18:33 ` SIMRAN SINGHAL 0 siblings, 2 replies; 5+ messages in thread From: Alison Schofield @ 2017-03-21 16:48 UTC (permalink / raw) To: simran singhal Cc: lars, Michael.Hennerich, jic23, Hartmut Knaack, Peter Meerwald-Stadler, Greg Kroah-Hartman, linux-iio, devel, linux-kernel, outreachy-kernel 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. > 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. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Outreachy kernel] [PATCH v6] staging: Use buf_lock instead of mlock and Refactor code 2017-03-21 16:48 ` [Outreachy kernel] " Alison Schofield @ 2017-03-21 17:04 ` SIMRAN SINGHAL 2017-03-21 17:47 ` Alison Schofield 2017-03-21 18:33 ` SIMRAN SINGHAL 1 sibling, 1 reply; 5+ messages in thread From: SIMRAN SINGHAL @ 2017-03-21 17:04 UTC (permalink / raw) To: Alison Schofield Cc: Lars-Peter Clausen, Michael Hennerich, Jonathan Cameron, Hartmut Knaack, Peter Meerwald-Stadler, Greg Kroah-Hartman, linux-iio, devel, linux-kernel, outreachy-kernel 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. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Outreachy kernel] [PATCH v6] staging: Use buf_lock instead of mlock and Refactor code 2017-03-21 17:04 ` SIMRAN SINGHAL @ 2017-03-21 17:47 ` Alison Schofield 0 siblings, 0 replies; 5+ messages in thread From: Alison Schofield @ 2017-03-21 17:47 UTC (permalink / raw) To: SIMRAN SINGHAL Cc: Lars-Peter Clausen, Michael Hennerich, Jonathan Cameron, Hartmut Knaack, Peter Meerwald-Stadler, Greg Kroah-Hartman, linux-iio, devel, linux-kernel, outreachy-kernel 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. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Outreachy kernel] [PATCH v6] staging: Use buf_lock instead of mlock and Refactor code 2017-03-21 16:48 ` [Outreachy kernel] " Alison Schofield 2017-03-21 17:04 ` SIMRAN SINGHAL @ 2017-03-21 18:33 ` SIMRAN SINGHAL 1 sibling, 0 replies; 5+ messages in thread From: SIMRAN SINGHAL @ 2017-03-21 18:33 UTC (permalink / raw) To: Alison Schofield Cc: Lars-Peter Clausen, Michael Hennerich, Jonathan Cameron, Hartmut Knaack, Peter Meerwald-Stadler, Greg Kroah-Hartman, linux-iio, devel, linux-kernel, outreachy-kernel 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 >> >> -- >> 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. ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2017-03-21 18:36 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2017-03-19 20:06 [PATCH v6] staging: Use buf_lock instead of mlock and Refactor code simran singhal 2017-03-21 16:48 ` [Outreachy kernel] " Alison Schofield 2017-03-21 17:04 ` SIMRAN SINGHAL 2017-03-21 17:47 ` Alison Schofield 2017-03-21 18:33 ` SIMRAN SINGHAL
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