Re: [PATCH] mmc: sdhci-xenon: fix 1.8v regulator stabilization

[Ulf Hansson]

On Fri, 11 Dec 2020 at 15:17, Marcin Wojtas <mw@xxxxxxxxxxxx> wrote:
>
> From: Alex Leibovich <alexl@xxxxxxxxxxx>
>
> 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@xxxxxxxxxxx>
> Signed-off-by: Marcin Wojtas <mw@xxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx

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
>