linux-kernel - [PATCH v2 5/5] iio: adc: ad7173: Fix sampling frequency setting

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] [day] [month] [year] [list]

Date: Mon, 27 May 2024 18:19:53 +0300
From: Dumitru Ceclan via B4 Relay <devnull+dumitru.ceclan.analog.com@...nel.org>
To: Lars-Peter Clausen <lars@...afoo.de>, 
 Jonathan Cameron <jic23@...nel.org>
Cc: linux-iio@...r.kernel.org, linux-kernel@...r.kernel.org, 
 Dumitru Ceclan <dumitru.ceclan@...log.com>
Subject: [PATCH v2 5/5] iio: adc: ad7173: Fix sampling frequency setting

From: Dumitru Ceclan <dumitru.ceclan@...log.com>

This patch fixes two issues regarding the sampling frequency setting:
-The attribute was set as per device, not per channel. As such, when
 setting the sampling frequency, the configuration was always done for
 the slot 0, and the correct configuration was applied on the next
 channel configuration call by the LRU mechanism.
-The LRU implementation does not take into account external settings of
 the slot registers. When setting the sampling frequency directly to a
 slot register in write_raw(), there is no guarantee that other channels
 were not also using that slot and now incorrectly retain their config
 as live.

Set the sampling frequency attribute as separate in the channel templates.
Do not set the sampling directly to the slot register in write_raw(),
just mark the config as not live and let the LRU mechanism handle it.
As the reg variable is no longer used, remove it.

Fixes: 8eb903272f75 ("iio: adc: ad7173: add AD7173 driver")
Signed-off-by: Dumitru Ceclan <dumitru.ceclan@...log.com>
---
 drivers/iio/adc/ad7173.c | 18 +++++-------------
 1 file changed, 5 insertions(+), 13 deletions(-)

diff --git a/drivers/iio/adc/ad7173.c b/drivers/iio/adc/ad7173.c
index e66a137a76be..ebacdacf64b9 100644
--- a/drivers/iio/adc/ad7173.c
+++ b/drivers/iio/adc/ad7173.c
@@ -717,7 +717,7 @@ static int ad7173_write_raw(struct iio_dev *indio_dev,
 {
 	struct ad7173_state *st = iio_priv(indio_dev);
 	struct ad7173_channel_config *cfg;
-	unsigned int freq, i, reg;
+	unsigned int freq, i;
 	int ret;
 
 	ret = iio_device_claim_direct_mode(indio_dev);
@@ -733,16 +733,7 @@ static int ad7173_write_raw(struct iio_dev *indio_dev,
 
 		cfg = &st->channels[chan->address].cfg;
 		cfg->odr = i;
-
-		if (!cfg->live)
-			break;
-
-		ret = ad_sd_read_reg(&st->sd, AD7173_REG_FILTER(cfg->cfg_slot), 2, &reg);
-		if (ret)
-			break;
-		reg &= ~AD7173_FILTER_ODR0_MASK;
-		reg |= FIELD_PREP(AD7173_FILTER_ODR0_MASK, i);
-		ret = ad_sd_write_reg(&st->sd, AD7173_REG_FILTER(cfg->cfg_slot), 2, reg);
+		cfg->live = false;
 		break;
 
 	default:
@@ -804,7 +795,7 @@ static const struct iio_chan_spec ad7173_channel_template = {
 	.type = IIO_VOLTAGE,
 	.indexed = 1,
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
-		BIT(IIO_CHAN_INFO_SCALE),
+		BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_SAMP_FREQ),
 	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
 	.scan_type = {
 		.sign = 'u',
@@ -819,7 +810,8 @@ static const struct iio_chan_spec ad7173_temp_iio_channel_template = {
 	.channel = AD7173_AIN_TEMP_POS,
 	.channel2 = AD7173_AIN_TEMP_NEG,
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
-		BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET),
+		BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET) |
+		BIT(IIO_CHAN_INFO_SAMP_FREQ),
 	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
 	.scan_type = {
 		.sign = 'u',

-- 
2.43.0