linux-kernel - Re: [PATCH v2 2/2] mmc: host: sdhci-esdhc-imx: refactor the system PM logic

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Message-ID: <0bda0bba-cfc6-403d-b36f-9c625e5bafb2@intel.com>
Date: Thu, 15 May 2025 15:52:43 +0300
From: Adrian Hunter <adrian.hunter@...el.com>
To: <ziniu.wang_1@....com>, <ulf.hansson@...aro.org>,
	<linux-mmc@...r.kernel.org>
CC: <haibo.chen@....com>, <shawnguo@...nel.org>, <s.hauer@...gutronix.de>,
	<kernel@...gutronix.de>, <festevam@...il.com>, <imx@...ts.linux.dev>,
	<s32@....com>, <linux-arm-kernel@...ts.infradead.org>,
	<linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 2/2] mmc: host: sdhci-esdhc-imx: refactor the system PM
 logic

On 14/05/2025 12:49, ziniu.wang_1@....com wrote:
> From: Luke Wang <ziniu.wang_1@....com>
> 
> Current suspend/resume logic has one issue. In suspend, will config
> register when call sdhci_suspend_host(), but at this time, can't
> guarantee host in runtime resume state. If not, the per clock is gate
> off, access register will hang.
> 
> In sdhci_esdhc_suspend/sdhci_esdhc_resume, remove sdhci_suspend_host()
> and sdhci_resume_host(), all are handled in runtime PM callbacks except
> the wakeup irq setting. For wakeup irq setting, use pm_runtime_get_sync()
> in sdhci_esdhc_suspend() to make sure clock gate on.
> 
> Remove pinctrl_pm_select_default_state() in sdhci_esdhc_resume, because
> pm_runtime_force_resume() already config the pinctrl state according to
> ios timing, and here config the default pinctrl state again is wrong for
> SDIO3.0 device if it keep power in suspend.
> 
> Signed-off-by: Haibo Chen <haibo.chen@....com>
> Signed-off-by: Luke Wang <ziniu.wang_1@....com>

Looks OK to me, at least, although Ulf may still have comments.
Otherwise, for both patches:

Acked-by: Adrian Hunter <adrian.hunter@...el.com>

> ---
>  drivers/mmc/host/sdhci-esdhc-imx.c | 50 ++++++++++++++++++------------
>  1 file changed, 30 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
> index c0160c69a027..7611682f10c3 100644
> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
> @@ -2009,11 +2009,14 @@ static int sdhci_esdhc_suspend(struct device *dev)
>  	struct pltfm_imx_data *imx_data = sdhci_pltfm_priv(pltfm_host);
>  	int ret;
>  
> -	if (host->mmc->caps2 & MMC_CAP2_CQE) {
> -		ret = cqhci_suspend(host->mmc);
> -		if (ret)
> -			return ret;
> -	}
> +	/*
> +	 * Switch to runtime resume for two reasons:
> +	 * 1, there is register access (e.g., wakeup control register), so
> +	 *    need to make sure gate on ipg clock.
> +	 * 2, make sure the pm_runtime_force_resume() in sdhci_esdhc_resume() really
> +	 *    invoke its ->runtime_resume callback (needs_force_resume = 1).
> +	 */
> +	pm_runtime_get_sync(dev);
>  
>  	if ((imx_data->socdata->flags & ESDHC_FLAG_STATE_LOST_IN_LPMODE) &&
>  		(host->tuning_mode != SDHCI_TUNING_MODE_1)) {
> @@ -2021,9 +2024,6 @@ static int sdhci_esdhc_suspend(struct device *dev)
>  		mmc_retune_needed(host->mmc);
>  	}
>  
> -	if (host->tuning_mode != SDHCI_TUNING_MODE_3)
> -		mmc_retune_needed(host->mmc);
> -
>  	/*
>  	 * For the device need to keep power during system PM, need
>  	 * to save the tuning delay value just in case the usdhc
> @@ -2033,9 +2033,13 @@ static int sdhci_esdhc_suspend(struct device *dev)
>  	    esdhc_is_usdhc(imx_data))
>  		sdhc_esdhc_tuning_save(host);
>  
> -	ret = sdhci_suspend_host(host);
> -	if (ret)
> -		return ret;
> +	if (device_may_wakeup(dev)) {
> +		/* The irqs of imx are not shared. It is safe to disable */
> +		disable_irq(host->irq);
> +		ret = sdhci_enable_irq_wakeups(host);
> +		if (!ret)
> +			dev_warn(dev, "Failed to enable irq wakeup\n");
> +	}
>  
>  	ret = pinctrl_pm_select_sleep_state(dev);
>  	if (ret)
> @@ -2043,6 +2047,12 @@ static int sdhci_esdhc_suspend(struct device *dev)
>  
>  	ret = mmc_gpio_set_cd_wake(host->mmc, true);
>  
> +	/*
> +	 * Make sure invoke runtime_suspend to gate off clock.
> +	 * uSDHC IP supports in-band SDIO wakeup even without clock.
> +	 */
> +	pm_runtime_force_suspend(dev);
> +
>  	return ret;
>  }
>  
> @@ -2053,16 +2063,19 @@ static int sdhci_esdhc_resume(struct device *dev)
>  	struct pltfm_imx_data *imx_data = sdhci_pltfm_priv(pltfm_host);
>  	int ret;
>  
> -	ret = pinctrl_pm_select_default_state(dev);
> +	pm_runtime_force_resume(dev);
> +
> +	ret = mmc_gpio_set_cd_wake(host->mmc, false);
>  	if (ret)
>  		return ret;
>  
>  	/* re-initialize hw state in case it's lost in low power mode */
>  	sdhci_esdhc_imx_hwinit(host);
>  
> -	ret = sdhci_resume_host(host);
> -	if (ret)
> -		return ret;
> +	if (host->irq_wake_enabled) {
> +		sdhci_disable_irq_wakeups(host);
> +		enable_irq(host->irq);
> +	}
>  
>  	/*
>  	 * restore the saved tuning delay value for the device which keep
> @@ -2072,11 +2085,8 @@ static int sdhci_esdhc_resume(struct device *dev)
>  	    esdhc_is_usdhc(imx_data))
>  		sdhc_esdhc_tuning_restore(host);
>  
> -	if (host->mmc->caps2 & MMC_CAP2_CQE)
> -		ret = cqhci_resume(host->mmc);
> -
> -	if (!ret)
> -		ret = mmc_gpio_set_cd_wake(host->mmc, false);
> +	pm_runtime_mark_last_busy(dev);
> +	pm_runtime_put_autosuspend(dev);
>  
>  	return ret;
>  }