Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Mario Tesi <mario.tesi@st.com>,
        Lorenzo Bianconi <lorenzo@kernel.org>, Stable@vger.kernel.org,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>
Subject: [PATCH 5.16 119/164] iio: imu: st_lsm6dsx: wait for settling time in st_lsm6dsx_read_oneshot
Date:   Mon, 28 Feb 2022 18:24:41 +0100
Message-Id: <20220228172411.078345606@linuxfoundation.org>
In-Reply-To: <20220228172359.567256961@linuxfoundation.org>
References: <20220228172359.567256961@linuxfoundation.org>
User-Agent: quilt/0.66
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Lorenzo Bianconi <lorenzo@kernel.org>

commit ea85bf906466191b58532bb19f4fbb4591f0a77e upstream.

We need to wait for sensor settling time (~ 3/ODR) before reading data
in st_lsm6dsx_read_oneshot routine in order to avoid corrupted samples.

Fixes: 290a6ce11d93 ("iio: imu: add support to lsm6dsx driver")
Reported-by: Mario Tesi <mario.tesi@st.com>
Tested-by: Mario Tesi <mario.tesi@st.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/b41ebda5535895298716c76d939f9f165fcd2d13.1644098120.git.lorenzo@kernel.org
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
+++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
@@ -1374,8 +1374,12 @@ static int st_lsm6dsx_read_oneshot(struc
 	if (err < 0)
 		return err;
 
+	/*
+	 * we need to wait for sensor settling time before
+	 * reading data in order to avoid corrupted samples
+	 */
 	delay = 1000000000 / sensor->odr;
-	usleep_range(delay, 2 * delay);
+	usleep_range(3 * delay, 4 * delay);
 
 	err = st_lsm6dsx_read_locked(hw, addr, &data, sizeof(data));
 	if (err < 0)