linux-kernel - [PATCH v4 7/9] iio: adc: ad7606: protect register access

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250210-wip-bl-ad7606_add_backend_sw_mode-v4-7-160df18b1da7@baylibre.com>
Date: Mon, 10 Feb 2025 17:10:57 +0100
From: Angelo Dureghello <adureghello@...libre.com>
To: Michael Hennerich <michael.hennerich@...log.com>, 
 Lars-Peter Clausen <lars@...afoo.de>, Jonathan Cameron <jic23@...nel.org>, 
 Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>, 
 Conor Dooley <conor+dt@...nel.org>, 
 Alexandru Ardelean <aardelean@...libre.com>, 
 David Lechner <dlechner@...libre.com>
Cc: Jonathan Cameron <Jonathan.Cameron@...wei.com>, 
 linux-fbdev@...r.kernel.org, linux-iio@...r.kernel.org, 
 devicetree@...r.kernel.org, linux-kernel@...r.kernel.org, 
 Guillaume Stols <gstols@...libre.com>, 
 Angelo Dureghello <adureghello@...libre.com>
Subject: [PATCH v4 7/9] iio: adc: ad7606: protect register access

From: Angelo Dureghello <adureghello@...libre.com>

Protect register (and bus) access from concurrent
read / write. Needed in the backend operating mode.

Signed-off-by: Angelo Dureghello <adureghello@...libre.com>
---
 drivers/iio/adc/ad7606.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c
index 7985570ed152..07656fdd602e 100644
--- a/drivers/iio/adc/ad7606.c
+++ b/drivers/iio/adc/ad7606.c
@@ -862,7 +862,12 @@ static int ad7606_write_raw(struct iio_dev *indio_dev,
 		}
 		val = (val * MICRO) + val2;
 		i = find_closest(val, scale_avail_uv, cs->num_scales);
+
+		ret = iio_device_claim_direct_mode(indio_dev);
+		if (ret < 0)
+			return ret;
 		ret = st->write_scale(indio_dev, ch, i + cs->reg_offset);
+		iio_device_release_direct_mode(indio_dev);
 		if (ret < 0)
 			return ret;
 		cs->range = i;
@@ -873,7 +878,12 @@ static int ad7606_write_raw(struct iio_dev *indio_dev,
 			return -EINVAL;
 		i = find_closest(val, st->oversampling_avail,
 				 st->num_os_ratios);
+
+		ret = iio_device_claim_direct_mode(indio_dev);
+		if (ret < 0)
+			return ret;
 		ret = st->write_os(indio_dev, i);
+		iio_device_release_direct_mode(indio_dev);
 		if (ret < 0)
 			return ret;
 		st->oversampling = st->oversampling_avail[i];

-- 
2.47.0