This is a note to let you know that I've just added the patch titled iio: adc: stm32: fix a current leak by resetting pcsel before disabling vdda 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-stm32-fix-a-current-leak-by-resetting-pcsel-before-disabling-vdda.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 f711f28e71e965c0d1141c830fa7131b41abbe75 Mon Sep 17 00:00:00 2001 From: Fabrice Gasnier <fabrice.gasnier@xxxxxxxxxxx> Date: Fri, 22 Oct 2021 14:19:29 +0200 Subject: iio: adc: stm32: fix a current leak by resetting pcsel before disabling vdda From: Fabrice Gasnier <fabrice.gasnier@xxxxxxxxxxx> commit f711f28e71e965c0d1141c830fa7131b41abbe75 upstream. Some I/Os are connected to ADC input channels, when the corresponding bit in PCSEL register are set on STM32H7 and STM32MP15. This is done in the prepare routine of stm32-adc driver. There are constraints here, as PCSEL shouldn't be set when VDDA supply is disabled. Enabling/disabling of VDDA supply in done via stm32-adc-core runtime PM routines (before/after ADC is enabled/disabled). Currently, PCSEL remains set when disabling ADC. Later on, PM runtime can disable the VDDA supply. This creates some conditions on I/Os that can start to leak current. So PCSEL needs to be cleared when disabling the ADC. Fixes: 95e339b6e85d ("iio: adc: stm32: add support for STM32H7") Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxxxxxxx> Reviewed-by: Olivier Moysan <olivier.moysan@xxxxxxxxxxx> Link: https://lore.kernel.org/r/1634905169-23762-1-git-send-email-fabrice.gasnier@xxxxxxxxxxx Cc: <Stable@xxxxxxxxxxxxxxx> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/iio/adc/stm32-adc.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/iio/adc/stm32-adc.c +++ b/drivers/iio/adc/stm32-adc.c @@ -933,6 +933,7 @@ pwr_dwn: static void stm32h7_adc_unprepare(struct stm32_adc *adc) { + stm32_adc_writel(adc, STM32H7_ADC_PCSEL, 0); stm32h7_adc_disable(adc); stm32h7_adc_enter_pwr_down(adc); } Patches currently in stable-queue which might be from fabrice.gasnier@xxxxxxxxxxx are queue-5.4/iio-adc-stm32-fix-a-current-leak-by-resetting-pcsel-before-disabling-vdda.patch