RE: [PATCH 2/4] mmc: sdhci-esdhc-imx: obtain the 'per' clock rate after its enablement

[Bough Chen]

> -----Original Message-----
> From: Ciprian Marian Costea (OSS) <ciprianmarian.costea@xxxxxxxxxxx>
> Sent: 2024年7月5日 21:47
> To: Bough Chen <haibo.chen@xxxxxxx>; Adrian Hunter
> <adrian.hunter@xxxxxxxxx>; Ulf Hansson <ulf.hansson@xxxxxxxxxx>; Shawn Guo
> <shawnguo@xxxxxxxxxx>; Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>;
> Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>; Fabio Estevam
> <festevam@xxxxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx; linux-mmc@xxxxxxxxxxxxxxx;
> imx@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; dl-S32
> <S32@xxxxxxx>; Ciprian Marian Costea (OSS)
> <ciprianmarian.costea@xxxxxxxxxxx>
> Subject: [PATCH 2/4] mmc: sdhci-esdhc-imx: obtain the 'per' clock rate after its
> enablement
> 
> The I.MX SDHCI driver assumes that the frequency of the 'per' clock can be
> obtained even on disabled clocks, which is not always the case.
> 
> According to 'clk_get_rate' documentation, it is only valid once the clock source
> has been enabled.

Reviewed-by: Haibo Chen <haibo.chen@xxxxxxx>

Thanks
Haibo Chen

> 
> Signed-off-by: Ciprian Costea <ciprianmarian.costea@xxxxxxxxxxx>
> ---
>  drivers/mmc/host/sdhci-esdhc-imx.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c
> b/drivers/mmc/host/sdhci-esdhc-imx.c
> index 21d984a77be8..8f0bc6dca2b0 100644
> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
> @@ -1709,7 +1709,6 @@ static int sdhci_esdhc_imx_probe(struct
> platform_device *pdev)
>  	}
> 
>  	pltfm_host->clk = imx_data->clk_per;
> -	pltfm_host->clock = clk_get_rate(pltfm_host->clk);
>  	err = clk_prepare_enable(imx_data->clk_per);
>  	if (err)
>  		goto free_sdhci;
> @@ -1720,6 +1719,13 @@ static int sdhci_esdhc_imx_probe(struct
> platform_device *pdev)
>  	if (err)
>  		goto disable_ipg_clk;
> 
> +	pltfm_host->clock = clk_get_rate(pltfm_host->clk);
> +	if (!pltfm_host->clock) {
> +		dev_err(mmc_dev(host->mmc), "could not get clk rate\n");
> +		err = -EINVAL;
> +		goto disable_ahb_clk;
> +	}
> +
>  	imx_data->pinctrl = devm_pinctrl_get(&pdev->dev);
>  	if (IS_ERR(imx_data->pinctrl))
>  		dev_warn(mmc_dev(host->mmc), "could not get pinctrl\n");
> --
> 2.45.2