Re: [PATCH v3 1/7] mmc: sdhci-esdhc-imx: remove unnecessary mmc_card_wake_sdio_irq check for tuning save/restore

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] This problem wasn't introduced by this patch, but the return value of `pm_runtime_get_sync()` is not checked in `sdhci_esdhc_imx_remove()`, which can lead to a system crash.
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commit 0d93ff3a6d9920d33acfc34fc6f5408ba83a9030
Author: Luke Wang <ziniu.wang_1@nxp.com>

mmc: sdhci-esdhc-imx: remove unnecessary mmc_card_wake_sdio_irq check for tuning save/restore

The tuning save/restore during system PM is conditioned on
mmc_card_wake_sdio_irq(), but this check is unrelated to whether
tuning values need to be preserved. The actual requirement is that
the card keeps power during suspend and the controller is a uSDHC.

> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
> index 18ecddd6df6f2..6526d65538de5 100644
> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
> @@ -2064,8 +2064,7 @@ static int sdhci_esdhc_suspend(struct device *dev)
>  	 * to save the tuning delay value just in case the usdhc
>  	 * lost power during system PM.
>  	 */
> -	if (mmc_card_keep_power(host->mmc) && mmc_card_wake_sdio_irq(host->mmc) &&
> -	    esdhc_is_usdhc(imx_data))
> +	if (mmc_card_keep_power(host->mmc) && esdhc_is_usdhc(imx_data))
>  		sdhc_esdhc_tuning_save(host);

[ ... ]

[Severity: High]
This isn't a bug introduced by this patch, but while reviewing this file I
noticed a potential issue in the nearby sdhci_esdhc_imx_remove() function:

drivers/mmc/host/sdhci-esdhc-imx.c:sdhci_esdhc_imx_remove() {
    ...
    pm_runtime_get_sync(&pdev->dev);
    dead = (readl(host->ioaddr + SDHCI_INT_STATUS) == 0xffffffff);
    ...
}

Should the return value of pm_runtime_get_sync() be checked here?

If pm_runtime_get_sync() fails and the device remains unclocked, could the
subsequent readl() on SDHCI_INT_STATUS trigger a synchronous external abort
or system crash due to accessing unclocked memory-mapped registers?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260629091954.3227151-1-ziniu.wang_1@oss.nxp.com?part=1