This is a note to let you know that I've just added the patch titled iio: adc: ad7949: fix wrong ADC result due to incorrect bit mask to the 5.4-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: iio-adc-ad7949-fix-wrong-adc-result-due-to-incorrect-bit-mask.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From f890987fac8153227258121740a9609668c427f3 Mon Sep 17 00:00:00 2001 From: Wilfried Wessner <wilfried.wessner@xxxxxxxxx> Date: Mon, 8 Feb 2021 15:27:05 +0100 Subject: iio: adc: ad7949: fix wrong ADC result due to incorrect bit mask From: Wilfried Wessner <wilfried.wessner@xxxxxxxxx> commit f890987fac8153227258121740a9609668c427f3 upstream. Fixes a wrong bit mask used for the ADC's result, which was caused by an improper usage of the GENMASK() macro. The bits higher than ADC's resolution are undefined and if not masked out correctly, a wrong result can be given. The GENMASK() macro indexing is zero based, so the mask has to go from [resolution - 1 , 0]. Fixes: 7f40e0614317f ("iio:adc:ad7949: Add AD7949 ADC driver family") Signed-off-by: Wilfried Wessner <wilfried.wessner@xxxxxxxxx> Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> Reviewed-by: Charles-Antoine Couret <charles-antoine.couret@xxxxxxxxxxxxx> Cc: <Stable@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210208142705.GA51260@ubuntu Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/iio/adc/ad7949.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/iio/adc/ad7949.c +++ b/drivers/iio/adc/ad7949.c @@ -91,7 +91,7 @@ static int ad7949_spi_read_channel(struc int ret; int i; int bits_per_word = ad7949_adc->resolution; - int mask = GENMASK(ad7949_adc->resolution, 0); + int mask = GENMASK(ad7949_adc->resolution - 1, 0); struct spi_message msg; struct spi_transfer tx[] = { { Patches currently in stable-queue which might be from wilfried.wessner@xxxxxxxxx are queue-5.4/iio-adc-ad7949-fix-wrong-adc-result-due-to-incorrect-bit-mask.patch