From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 178DFC433FE for ; Thu, 28 Oct 2021 14:14:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EE91F61073 for ; Thu, 28 Oct 2021 14:14:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230265AbhJ1ORY (ORCPT ); Thu, 28 Oct 2021 10:17:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:50492 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230258AbhJ1ORX (ORCPT ); Thu, 28 Oct 2021 10:17:23 -0400 Received: from jic23-huawei (cpc108967-cmbg20-2-0-cust86.5-4.cable.virginm.net [81.101.6.87]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E948160238; Thu, 28 Oct 2021 14:14:54 +0000 (UTC) Date: Thu, 28 Oct 2021 15:19:21 +0100 From: Jonathan Cameron To: Fabrice Gasnier Cc: Olivier MOYSAN , , , , , Subject: Re: [PATCH] iio: adc: stm32: fix a leak by resetting pcsel before disabling vdda Message-ID: <20211028151921.761c1413@jic23-huawei> In-Reply-To: <76ac386a-a748-f044-13c5-46b164738338@foss.st.com> References: <1634905169-23762-1-git-send-email-fabrice.gasnier@foss.st.com> <77f3593a-0e94-f5ab-f102-86ba8d0f1a3b@foss.st.com> <20211024170749.44c0d81f@jic23-huawei> <76ac386a-a748-f044-13c5-46b164738338@foss.st.com> X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Mon, 25 Oct 2021 09:43:10 +0200 Fabrice Gasnier wrote: > On 10/24/21 6:07 PM, Jonathan Cameron wrote: > > On Fri, 22 Oct 2021 14:38:52 +0200 > > Olivier MOYSAN wrote: > > > > I'll probably reword the description here as 'leak' tends to mean memory > > leak rather than current. > > Hi Jonathan, > > Yes, please fell free to improve this. I had the same concern, but I > haven't found a more suitable description. Added the word current to the title which I think makes it clear. > > > > >> Hi Fabrice, > >> > >> On 10/22/21 2:19 PM, Fabrice Gasnier wrote: > >>> 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") > >>> > > > > No line break here as Fixes forms part of the tag block. > > > > Sorry, will check this next time. > > >>> Signed-off-by: Fabrice Gasnier > > > > Given timing wrt to being too near merge window, I'll let this it on > > list a while longer as it'll be post rc1 material now anyway. > > > > I can fix the above whilst applying if nothing else comes up. > > That's fine for me. Applied to the fixes-togreg branch of iio.git, targeting a pull request some time shortly after rc1. Thanks, Jonathan > > Many thanks, > Fabrice > > > > Jonathan > > > >>> --- > >>> drivers/iio/adc/stm32-adc.c | 1 + > >>> 1 file changed, 1 insertion(+) > >>> > >>> diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c > >>> index 5088de8..e3e7541 100644 > >>> --- a/drivers/iio/adc/stm32-adc.c > >>> +++ b/drivers/iio/adc/stm32-adc.c > >>> @@ -975,6 +975,7 @@ static void stm32h7_adc_unprepare(struct iio_dev *indio_dev) > >>> { > >>> struct stm32_adc *adc = iio_priv(indio_dev); > >>> > >>> + stm32_adc_writel(adc, STM32H7_ADC_PCSEL, 0); > >>> stm32h7_adc_disable(indio_dev); > >>> stm32h7_adc_enter_pwr_down(adc); > >>> } > >>> > >> > >> Reviewed-by: Olivier Moysan > >> > >> Thanks > >> Olivier > >