This is a note to let you know that I've just added the patch titled
drivers: iio: adc: ltc2497: fix LSB shift
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drivers-iio-adc-ltc2497-fix-lsb-shift.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 6327a930ab7bfa1ab33bcdffd5f5f4b1e7131504 Mon Sep 17 00:00:00 2001
From: Ian Ray <ian.ray@xxxxxx>
Date: Fri, 27 Jan 2023 14:57:14 +0200
Subject: drivers: iio: adc: ltc2497: fix LSB shift
From: Ian Ray <ian.ray@xxxxxx>
commit 6327a930ab7bfa1ab33bcdffd5f5f4b1e7131504 upstream.
Correct the "sub_lsb" shift for the ltc2497 and drop the sub_lsb element
which is now constant.
An earlier version of the code shifted by 14 but this was a consequence
of reading three bytes into a __be32 buffer and using be32_to_cpu(), so
eight extra bits needed to be skipped. Now we use get_unaligned_be24()
and thus the additional skip is wrong.
Fixes: 2187cfeb3626 ("drivers: iio: adc: ltc2497: LTC2499 support")
Signed-off-by: Ian Ray <ian.ray@xxxxxx>
Link: https://lore.kernel.org/r/20230127125714.44608-1-ian.ray@xxxxxx
Cc: <Stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/iio/adc/ltc2497.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/iio/adc/ltc2497.c b/drivers/iio/adc/ltc2497.c
index 17370c5eb6fe..ec198c6f13d6 100644
--- a/drivers/iio/adc/ltc2497.c
+++ b/drivers/iio/adc/ltc2497.c
@@ -28,7 +28,6 @@ struct ltc2497_driverdata {
struct ltc2497core_driverdata common_ddata;
struct i2c_client *client;
u32 recv_size;
- u32 sub_lsb;
/*
* DMA (thus cache coherency maintenance) may require the
* transfer buffers to live in their own cache lines.
@@ -65,10 +64,10 @@ static int ltc2497_result_and_measure(struct ltc2497core_driverdata *ddata,
* equivalent to a sign extension.
*/
if (st->recv_size == 3) {
- *val = (get_unaligned_be24(st->data.d8) >> st->sub_lsb)
+ *val = (get_unaligned_be24(st->data.d8) >> 6)
- BIT(ddata->chip_info->resolution + 1);
} else {
- *val = (be32_to_cpu(st->data.d32) >> st->sub_lsb)
+ *val = (be32_to_cpu(st->data.d32) >> 6)
- BIT(ddata->chip_info->resolution + 1);
}
@@ -122,7 +121,6 @@ static int ltc2497_probe(struct i2c_client *client)
st->common_ddata.chip_info = chip_info;
resolution = chip_info->resolution;
- st->sub_lsb = 31 - (resolution + 1);
st->recv_size = BITS_TO_BYTES(resolution) + 1;
return ltc2497core_probe(dev, indio_dev);
--
2.40.0
Patches currently in stable-queue which might be from ian.ray@xxxxxx are
queue-6.1/drivers-iio-adc-ltc2497-fix-lsb-shift.patch
