Commit 809d605d authored by Jonathan Santos's avatar Jonathan Santos Committed by Jonathan Cameron
Browse files

iio: adc: ad7768-1: remove unnecessary locking 



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() instead in the register access function.

Reviewed-by: default avatarDavid Lechner <dlechner@baylibre.com>
Signed-off-by: default avatarJonathan Santos <Jonathan.Santos@analog.com>
Link: https://patch.msgid.link/d0450b7c5d8467e54913ef905f6147baa2b866b3.1741268122.git.Jonathan.Santos@analog.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 20182142

drivers/iio/adc/ad7768-1.c

+8 −12
Original line number Diff line number Diff line
@@ -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 +255,20 @@ static int ad7768_reg_access(struct iio_dev *indio_dev, 
	struct ad7768_state *st = iio_priv(indio_dev);

	int ret;



	mutex_lock(&st->lock);

	if (!iio_device_claim_direct(indio_dev))

		return -EBUSY;



	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(indio_dev);



	return ret;

}
@@ -469,18 +470,15 @@ 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;

}
@@ -609,8 +607,6 @@ 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;