From 1555790c86286933dc674fffe9c1104250d093ce Mon Sep 17 00:00:00 2001 From: Nuno Sá Date: Wed, 12 Oct 2022 17:16:18 +0200 Subject: iio: health: max30100: do not use internal iio_dev lock MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The pattern used in this device does not quite fit in the iio_device_claim_direct_mode() typical usage. In this case, iio_buffer_enabled() was being used not to prevent the raw access but to allow it. Hence, let's make use of the new iio_device_claim_buffer_mode() API to make sure we stay in buffered mode during the complete read. Note that we are shadowing the error code returned by iio_device_claim_buffer_mode() so that we keep the original one (-EAGAIN). The reason is that some userspace stack might already be relying on this particular code so that we are not taking chances and leave it alone. Signed-off-by: Nuno Sá Link: https://lore.kernel.org/r/20221012151620.1725215-3-nuno.sa@analog.com Signed-off-by: Jonathan Cameron --- drivers/iio/health/max30100.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) (limited to 'drivers/iio/health/max30100.c') diff --git a/drivers/iio/health/max30100.c b/drivers/iio/health/max30100.c index 2cca5e0519f8..3aa5d037a1c3 100644 --- a/drivers/iio/health/max30100.c +++ b/drivers/iio/health/max30100.c @@ -387,18 +387,21 @@ static int max30100_read_raw(struct iio_dev *indio_dev, * Temperature reading can only be acquired while engine * is running */ - mutex_lock(&indio_dev->mlock); - - if (!iio_buffer_enabled(indio_dev)) + if (iio_device_claim_buffer_mode(indio_dev)) { + /* + * Replacing -EBUSY or other error code + * returned by iio_device_claim_buffer_mode() + * because user space may rely on the current + * one. + */ ret = -EAGAIN; - else { + } else { ret = max30100_get_temp(data, val); if (!ret) ret = IIO_VAL_INT; + iio_device_release_buffer_mode(indio_dev); } - - mutex_unlock(&indio_dev->mlock); break; case IIO_CHAN_INFO_SCALE: *val = 1; /* 0.0625 */ -- cgit v1.2.3