| Message ID | d0450b7c5d8467e54913ef905f6147baa2b866b3.1741268122.git.Jonathan.Santos@analog.com |
|---|---|
| State | New |
| Headers | show |
| Series | iio: adc: ad7768-1: Add features, improvements, and fixes | expand |
On Thu, 6 Mar 2025 18:01:51 -0300 Jonathan Santos <Jonathan.Santos@analog.com> wrote: > The current locking is only preventing a triggered buffer Transfer and a > debugfs register access from happening at the same time. If a register > access happens during a buffered read, the action is doomed to fail anyway, > since we need to write a magic value to exit continuous read mode. > > Remove locking from the trigger handler and use > iio_device_claim_direct_mode() instead in the register access function. > > Reviewed-by: David Lechner <dlechner@baylibre.com> > Signed-off-by: Jonathan Santos <Jonathan.Santos@analog.com> I don't really want more of the old school direct_mode calls so I applied this with following tweak. Please take a look at the result on testing branch of iio.git. diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c index a427427aa324..5a863005aca6 100644 --- a/drivers/iio/adc/ad7768-1.c +++ b/drivers/iio/adc/ad7768-1.c @@ -255,9 +255,8 @@ static int ad7768_reg_access(struct iio_dev *indio_dev, struct ad7768_state *st = iio_priv(indio_dev); int ret; - ret = iio_device_claim_direct_mode(indio_dev); - if (ret) - return ret; + if (!iio_device_claim_direct(indio_dev)) + return -EBUSY; if (readval) { ret = ad7768_spi_reg_read(st, reg, 1); @@ -269,7 +268,7 @@ static int ad7768_reg_access(struct iio_dev *indio_dev, ret = ad7768_spi_reg_write(st, reg, writeval); } err_release: - iio_device_release_direct_mode(indio_dev); + iio_device_release_direct(indio_dev); return ret; } > --- > v4 Changes: > * None. > > v3 Changes: > * Also removed the mutex_init and lock variable. > > v2 Changes: > * New patch in v2. It replaces the guard(mutex) patch. > --- > drivers/iio/adc/ad7768-1.c | 21 +++++++++------------ > 1 file changed, 9 insertions(+), 12 deletions(-) > > diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c > index 2e2d50ccb744..f5509a0a36ab 100644 > --- a/drivers/iio/adc/ad7768-1.c > +++ b/drivers/iio/adc/ad7768-1.c > @@ -154,7 +154,6 @@ static const struct iio_chan_spec ad7768_channels[] = { > struct ad7768_state { > struct spi_device *spi; > struct regulator *vref; > - struct mutex lock; > struct clk *mclk; > unsigned int mclk_freq; > unsigned int samp_freq; > @@ -256,18 +255,21 @@ static int ad7768_reg_access(struct iio_dev *indio_dev, > struct ad7768_state *st = iio_priv(indio_dev); > int ret; > > - mutex_lock(&st->lock); > + ret = iio_device_claim_direct_mode(indio_dev); > + if (ret) > + return ret; > + > if (readval) { > ret = ad7768_spi_reg_read(st, reg, 1); > if (ret < 0) > - goto err_unlock; > + goto err_release; > *readval = ret; > ret = 0; > } else { > ret = ad7768_spi_reg_write(st, reg, writeval); > } > -err_unlock: > - mutex_unlock(&st->lock); > +err_release: > + iio_device_release_direct_mode(indio_dev); > > return ret; > } > @@ -471,18 +473,15 @@ static irqreturn_t ad7768_trigger_handler(int irq, void *p) > struct ad7768_state *st = iio_priv(indio_dev); > int ret; > > - mutex_lock(&st->lock); > - > ret = spi_read(st->spi, &st->data.scan.chan, 3); > if (ret < 0) > - goto err_unlock; > + goto out; > > iio_push_to_buffers_with_timestamp(indio_dev, &st->data.scan, > iio_get_time_ns(indio_dev)); > > -err_unlock: > +out: > iio_trigger_notify_done(indio_dev->trig); > - mutex_unlock(&st->lock); > > return IRQ_HANDLED; > } > @@ -611,8 +610,6 @@ static int ad7768_probe(struct spi_device *spi) > > st->mclk_freq = clk_get_rate(st->mclk); > > - mutex_init(&st->lock); > - > indio_dev->channels = ad7768_channels; > indio_dev->num_channels = ARRAY_SIZE(ad7768_channels); > indio_dev->name = spi_get_device_id(spi)->name;
diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c index 2e2d50ccb744..f5509a0a36ab 100644 --- a/drivers/iio/adc/ad7768-1.c +++ b/drivers/iio/adc/ad7768-1.c @@ -154,7 +154,6 @@ static const struct iio_chan_spec ad7768_channels[] = { struct ad7768_state { struct spi_device *spi; struct regulator *vref; - struct mutex lock; struct clk *mclk; unsigned int mclk_freq; unsigned int samp_freq; @@ -256,18 +255,21 @@ static int ad7768_reg_access(struct iio_dev *indio_dev, struct ad7768_state *st = iio_priv(indio_dev); int ret; - mutex_lock(&st->lock); + ret = iio_device_claim_direct_mode(indio_dev); + if (ret) + return ret; + if (readval) { ret = ad7768_spi_reg_read(st, reg, 1); if (ret < 0) - goto err_unlock; + goto err_release; *readval = ret; ret = 0; } else { ret = ad7768_spi_reg_write(st, reg, writeval); } -err_unlock: - mutex_unlock(&st->lock); +err_release: + iio_device_release_direct_mode(indio_dev); return ret; } @@ -471,18 +473,15 @@ static irqreturn_t ad7768_trigger_handler(int irq, void *p) struct ad7768_state *st = iio_priv(indio_dev); int ret; - mutex_lock(&st->lock); - ret = spi_read(st->spi, &st->data.scan.chan, 3); if (ret < 0) - goto err_unlock; + goto out; iio_push_to_buffers_with_timestamp(indio_dev, &st->data.scan, iio_get_time_ns(indio_dev)); -err_unlock: +out: iio_trigger_notify_done(indio_dev->trig); - mutex_unlock(&st->lock); return IRQ_HANDLED; } @@ -611,8 +610,6 @@ static int ad7768_probe(struct spi_device *spi) st->mclk_freq = clk_get_rate(st->mclk); - mutex_init(&st->lock); - indio_dev->channels = ad7768_channels; indio_dev->num_channels = ARRAY_SIZE(ad7768_channels); indio_dev->name = spi_get_device_id(spi)->name;