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Date:   Thu, 9 Jul 2020 17:52:33 -0700
From:   Matthias Kaehlcke <mka@chromium.org>
To:     Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
Cc:     adrian.hunter@intel.com, ulf.hansson@linaro.org,
        bjorn.andersson@linaro.org, linux-mmc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        Andy Gross <agross@kernel.org>
Subject: Re: [PATCH V1] mmc: sdhci-msm: Set IO pins in low power state during
 suspend
Message-ID: <20200710005233.GN3191083@google.com>
References: <1594213888-2780-1-git-send-email-vbadigan@codeaurora.org>
 <1594213888-2780-2-git-send-email-vbadigan@codeaurora.org>
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Hi,

On Wed, Jul 08, 2020 at 06:41:20PM +0530, Veerabhadrarao Badiganti wrote:
> Configure SDHC IO pins with low power configuration when the driver
> is in suspend state.
> 
> Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
> ---
>  drivers/mmc/host/sdhci-msm.c | 17 +++++++++++++++++
>  1 file changed, 17 insertions(+)
> 
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 392d41d57a6e..efd2bae1430c 100644
> --- a/drivers/mmc/host/sdhci-msm.c
> +++ b/drivers/mmc/host/sdhci-msm.c
> @@ -15,6 +15,7 @@
>  #include <linux/iopoll.h>
>  #include <linux/regulator/consumer.h>
>  #include <linux/interconnect.h>
> +#include <linux/pinctrl/consumer.h>
>  
>  #include "sdhci-pltfm.h"
>  #include "cqhci.h"
> @@ -1352,6 +1353,19 @@ static void sdhci_msm_set_uhs_signaling(struct sdhci_host *host,
>  		sdhci_msm_hs400(host, &mmc->ios);
>  }
>  
> +static int sdhci_msm_set_pincfg(struct sdhci_msm_host *msm_host, bool level)
> +{
> +	struct platform_device *pdev = msm_host->pdev;
> +	int ret;
> +
> +	if (level)
> +		ret = pinctrl_pm_select_default_state(&pdev->dev);
> +	else
> +		ret = pinctrl_pm_select_sleep_state(&pdev->dev);
> +
> +	return ret;
> +}
> +
>  static int sdhci_msm_set_vmmc(struct mmc_host *mmc)
>  {
>  	if (IS_ERR(mmc->supply.vmmc))
> @@ -1596,6 +1610,9 @@ static void sdhci_msm_handle_pwr_irq(struct sdhci_host *host, int irq)
>  			ret = sdhci_msm_set_vqmmc(msm_host, mmc,
>  					pwr_state & REQ_BUS_ON);
>  		if (!ret)
> +			ret = sdhci_msm_set_pincfg(msm_host,
> +					pwr_state & REQ_BUS_ON);
> +		if (!ret)
>  			irq_ack |= CORE_PWRCTL_BUS_SUCCESS;
>  		else
>  			irq_ack |= CORE_PWRCTL_BUS_FAIL;

I happened to have a debug patch in my tree which logs when regulators
are enabled/disabled, with this patch I see the SD card regulator
toggling constantly after returning from the first system suspend.

I added more logs:

[ 1156.085819] DBG: sdhci_msm_set_pincfg: level = 0 (ret: 0)
[ 1156.248936] DBG: sdhci_msm_set_pincfg: level = 1 (ret: 0)
[ 1156.301989] DBG: sdhci_msm_set_pincfg: level = 0 (ret: 0)
[ 1156.462383] DBG: sdhci_msm_set_pincfg: level = 1 (ret: 0)
[ 1156.525988] DBG: sdhci_msm_set_pincfg: level = 0 (ret: 0)
[ 1156.670372] DBG: sdhci_msm_set_pincfg: level = 1 (ret: 0)
[ 1156.717935] DBG: sdhci_msm_set_pincfg: level = 0 (ret: 0)
[ 1156.878122] DBG: sdhci_msm_set_pincfg: level = 1 (ret: 0)
[ 1156.928134] DBG: sdhci_msm_set_pincfg: level = 0 (ret: 0)

This is on an SC7180 platform. It doesn't run an upstream kernel though,
but v5.4 with plenty of upstream patches.