linux-kernel - Re: [PATCH 2/3] mmc: sdhci-esdhc-imx: obtain the 'per' clock rate after its enablement

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <dbd73f2b-54ab-4832-9610-a4bc70e3b9f2@intel.com>
Date: Wed, 10 Jul 2024 15:33:34 +0300
From: Adrian Hunter <adrian.hunter@...el.com>
To: Ciprian Costea <ciprianmarian.costea@....nxp.com>,
 Haibo Chen <haibo.chen@....com>, Ulf Hansson <ulf.hansson@...aro.org>,
 Shawn Guo <shawnguo@...nel.org>, Sascha Hauer <s.hauer@...gutronix.de>,
 Pengutronix Kernel Team <kernel@...gutronix.de>,
 Fabio Estevam <festevam@...il.com>
Cc: linux-kernel@...r.kernel.org, linux-mmc@...r.kernel.org,
 imx@...ts.linux.dev, linux-arm-kernel@...ts.infradead.org, s32@....com
Subject: Re: [PATCH 2/3] mmc: sdhci-esdhc-imx: obtain the 'per' clock rate
 after its enablement

On 8/07/24 15:10, Ciprian Costea wrote:
> 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.

The kerneldoc comment for clk_get_rate() says

	Can be called regardless of the clock enabledness

which sounds like the opposite.  Please clarify.

> 
> Signed-off-by: Ciprian Costea <ciprianmarian.costea@....nxp.com>
> ---
>  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");