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From:   Ulf Hansson <ulf.hansson@linaro.org>
Date:   Mon, 11 Jan 2021 19:06:24 +0100
Message-ID: <CAPDyKFqsSO+f9iG8vccwXZXDDNHgLEg7bfUe-KfHn2C-ZnOU4A@mail.gmail.com>
Subject: Re: [PATCH] mmc: sdhci-xenon: fix 1.8v regulator stabilization
To:     Marcin Wojtas <mw@semihalf.com>
Cc:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
        Ziji Hu <huziji@marvell.com>,
        Adrian Hunter <adrian.hunter@intel.com>, jaz@semihalf.com,
        tn@semihalf.com, Kostya Porotchkin <kostap@marvell.com>,
        Alex Leibovich <alexl@marvell.com>,
        "# 4.0+" <stable@vger.kernel.org>
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On Fri, 11 Dec 2020 at 15:17, Marcin Wojtas <mw@semihalf.com> wrote:
>
> From: Alex Leibovich <alexl@marvell.com>
>
> Automatic Clock Gating is a feature used for the power
> consumption optimisation. It turned out that
> during early init phase it may prevent the stable voltage
> switch to 1.8V - due to that on some platfroms an endless
> printout in dmesg can be observed:
> "mmc1: 1.8V regulator output did not became stable"
> Fix the problem by disabling the ACG at very beginning
> of the sdhci_init and let that be enabled later.
>
> Fixes: 3a3748dba881 ("mmc: sdhci-xenon: Add Marvell Xenon SDHC core functionality")
> Signed-off-by: Alex Leibovich <alexl@marvell.com>
> Signed-off-by: Marcin Wojtas <mw@semihalf.com>
> Cc: stable@vger.kernel.org

Applied for fixes (by fixing the typos), thanks!

Kind regards
Uffe


> ---
>  drivers/mmc/host/sdhci-xenon.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci-xenon.c b/drivers/mmc/host/sdhci-xenon.c
> index c67611fdaa8a..4b05f6fdefb4 100644
> --- a/drivers/mmc/host/sdhci-xenon.c
> +++ b/drivers/mmc/host/sdhci-xenon.c
> @@ -168,7 +168,12 @@ static void xenon_reset_exit(struct sdhci_host *host,
>         /* Disable tuning request and auto-retuning again */
>         xenon_retune_setup(host);
>
> -       xenon_set_acg(host, true);
> +       /*
> +        * The ACG should be turned off at the early init time, in order
> +        * to solve a possile issues with the 1.8V regulator stabilization.
> +        * The feature is enabled in later stage.
> +        */
> +       xenon_set_acg(host, false);
>
>         xenon_set_sdclk_off_idle(host, sdhc_id, false);
>
> --
> 2.29.0
>