patch "iio: adc: ad7124: fix chip ID mismatch" added to char-misc-linus

patch "iio: adc: ad7124: fix chip ID mismatch" added to char-misc-linus

[gregkh]

This is a note to let you know that I've just added the patch titled

    iio: adc: ad7124: fix chip ID mismatch

to my char-misc git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.


From 96f9ab0d5933c1c00142dd052f259fce0bc3ced2 Mon Sep 17 00:00:00 2001
From: Dumitru Ceclan <mitrutzceclan@gmail.com>
Date: Wed, 31 Jul 2024 15:37:22 +0300
Subject: iio: adc: ad7124: fix chip ID mismatch

The ad7124_soft_reset() function has the assumption that the chip will
assert the "power-on reset" bit in the STATUS register after a software
reset without any delay. The POR bit =0 is used to check if the chip
initialization is done.

A chip ID mismatch probe error appears intermittently when the probe
continues too soon and the ID register does not contain the expected
value.

Fix by adding a 200us delay after the software reset command is issued.

Fixes: b3af341bbd96 ("iio: adc: Add ad7124 support")
Signed-off-by: Dumitru Ceclan <dumitru.ceclan@analog.com>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Link: https://patch.msgid.link/20240731-ad7124-fix-v1-1-46a76aa4b9be@analog.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
---
 drivers/iio/adc/ad7124.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/iio/adc/ad7124.c b/drivers/iio/adc/ad7124.c
index 3beed78496c5..c0b82f64c976 100644
--- a/drivers/iio/adc/ad7124.c
+++ b/drivers/iio/adc/ad7124.c
@@ -764,6 +764,7 @@ static int ad7124_soft_reset(struct ad7124_state *st)
 	if (ret < 0)
 		return ret;
 
+	fsleep(200);
 	timeout = 100;
 	do {
 		ret = ad_sd_read_reg(&st->sd, AD7124_STATUS, 1, &readval);
-- 
2.46.0