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From: Greg KH <gregkh@linuxfoundation.org>
To: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Cc: stable@vger.kernel.org, sashal@kernel.org
Subject: Re: [PATCH 5.4] iio: adc: stm32: fix a current leak by resetting pcsel before disabling vdda
Date: Fri, 17 Dec 2021 14:43:38 +0100	[thread overview]
Message-ID: <YbyUCoCQaOThT9ff@kroah.com> (raw)
In-Reply-To: <1639738592-28572-1-git-send-email-fabrice.gasnier@foss.st.com>

On Fri, Dec 17, 2021 at 11:56:32AM +0100, Fabrice Gasnier wrote:
> 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@foss.st.com>
> Reviewed-by: Olivier Moysan <olivier.moysan@foss.st.com>
> Link: https://lore.kernel.org/r/1634905169-23762-1-git-send-email-fabrice.gasnier@foss.st.com
> Cc: <Stable@vger.kernel.org>
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
> Backport for 5.4-stable

Now queued up, thanks.

greg k-h

      reply	other threads:[~2021-12-17 13:43 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-17 10:56 [PATCH 5.4] iio: adc: stm32: fix a current leak by resetting pcsel before disabling vdda Fabrice Gasnier
2021-12-17 13:43 ` Greg KH [this message]

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