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[v1,1/1] mmc: sdhci-of-dwcmshc: Add runtime PM operations for BlueField-3

Message ID 79137159a833c164ea8ea3f05d8d6d9537db2f42.1683747334.git.limings@nvidia.com
State New
Headers show
Series [v1,1/1] mmc: sdhci-of-dwcmshc: Add runtime PM operations for BlueField-3 | expand

Commit Message

Liming Sun May 11, 2023, 7:03 p.m. UTC 
This commit implements the runtime PM operations for BlueField-3 SoC
to disable eMMC card clock when idle.

Reviewed-by: David Thompson <davthompson@nvidia.com>
Signed-off-by: Liming Sun <limings@nvidia.com>
---
 drivers/mmc/host/sdhci-of-dwcmshc.c | 76 ++++++++++++++++++++++++++++-
 1 file changed, 74 insertions(+), 2 deletions(-)

Comments

Ulf Hansson May 12, 2023, 7:35 a.m. UTC | #1 
On Thu, 11 May 2023 at 21:03, Liming Sun <limings@nvidia.com> wrote:
>
> This commit implements the runtime PM operations for BlueField-3 SoC
> to disable eMMC card clock when idle.
>
> Reviewed-by: David Thompson <davthompson@nvidia.com>
> Signed-off-by: Liming Sun <limings@nvidia.com>
> ---
>  drivers/mmc/host/sdhci-of-dwcmshc.c | 76 ++++++++++++++++++++++++++++-
>  1 file changed, 74 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
> index e68cd87998c8..19ce058fc5f0 100644
> --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
> +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
> @@ -15,6 +15,7 @@
>  #include <linux/module.h>
>  #include <linux/of.h>
>  #include <linux/of_device.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/reset.h>
>  #include <linux/sizes.h>
>
> @@ -542,8 +543,10 @@ static int dwcmshc_probe(struct platform_device *pdev)
>         }
>
>  #ifdef CONFIG_ACPI
> -       if (pltfm_data == &sdhci_dwcmshc_bf3_pdata)
> +       if (pltfm_data == &sdhci_dwcmshc_bf3_pdata) {
>                 sdhci_enable_v4_mode(host);
> +               pm_runtime_enable(dev);

Why make this ACPI specific? Wouldn't other platforms benefit from
this change too?

[...]

Kind regards
Uffe
Liming Sun May 12, 2023, 12:09 p.m. UTC | #2 
> -----Original Message-----
> From: Ulf Hansson <ulf.hansson@linaro.org>
> Sent: Friday, May 12, 2023 3:36 AM
> To: Liming Sun <limings@nvidia.com>
> Cc: Adrian Hunter <adrian.hunter@intel.com>; David Thompson
> <davthompson@nvidia.com>; linux-mmc@vger.kernel.org; linux-
> kernel@vger.kernel.org
> Subject: Re: [PATCH v1 1/1] mmc: sdhci-of-dwcmshc: Add runtime PM
> operations for BlueField-3
> 
> On Thu, 11 May 2023 at 21:03, Liming Sun <limings@nvidia.com> wrote:
> >
> > This commit implements the runtime PM operations for BlueField-3 SoC
> > to disable eMMC card clock when idle.
> >
> > Reviewed-by: David Thompson <davthompson@nvidia.com>
> > Signed-off-by: Liming Sun <limings@nvidia.com>
> > ---
> >  drivers/mmc/host/sdhci-of-dwcmshc.c | 76
> ++++++++++++++++++++++++++++-
> >  1 file changed, 74 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-
> of-dwcmshc.c
> > index e68cd87998c8..19ce058fc5f0 100644
> > --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
> > +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
> > @@ -15,6 +15,7 @@
> >  #include <linux/module.h>
> >  #include <linux/of.h>
> >  #include <linux/of_device.h>
> > +#include <linux/pm_runtime.h>
> >  #include <linux/reset.h>
> >  #include <linux/sizes.h>
> >
> > @@ -542,8 +543,10 @@ static int dwcmshc_probe(struct platform_device
> *pdev)
> >         }
> >
> >  #ifdef CONFIG_ACPI
> > -       if (pltfm_data == &sdhci_dwcmshc_bf3_pdata)
> > +       if (pltfm_data == &sdhci_dwcmshc_bf3_pdata) {
> >                 sdhci_enable_v4_mode(host);
> > +               pm_runtime_enable(dev);
> 
> Why make this ACPI specific? Wouldn't other platforms benefit from
> this change too?

Sure, let me post v2 to make it generic for sdhci-of-dwcmshc.

> 
> [...]
> 
> Kind regards
> Uffe
Adrian Hunter Aug. 17, 2023, 7:35 a.m. UTC | #3 
On 17/08/23 04:06, Liming Sun wrote:
> This commit implements the runtime PM operations to disable eMMC
> card clock when idle.
> 
> Reviewed-by: David Thompson <davthompson@nvidia.com>
> Signed-off-by: Liming Sun <limings@nvidia.com>
> ---
> v7->v8:
>     - Address Ulf's comment (option-1);
>     - Updates for Adrian;s comment to remove the force_suspend/resume
>       in dwcmshc_resume()/dwcmshc_suspend(); Add comments for
>       dwcmshc_resume()/dwcmshc_suspend();
> v6->v7:
>     - Address Ulf's comment;
> v5->v6:
>     - Address Adrian's more comments and add coordination between
>       runtime PM and system PM;
> v4->v5:
>     - Address Adrian's comment to move the pm_enable to the end to
>       avoid race;
> v3->v4:
>     - Fix compiling reported by 'kernel test robot';
> v2->v3:
>     - Revise the commit message;
> v1->v2:
>     Updates for comments from Ulf:
>     - Make the runtime PM logic generic for sdhci-of-dwcmshc;
> v1: Initial version.
> ---
>  drivers/mmc/host/sdhci-of-dwcmshc.c | 76 +++++++++++++++++++++++++++--
>  1 file changed, 73 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
> index e68cd87998c8..2196218c9d79 100644
> --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
> +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
> @@ -15,6 +15,7 @@
>  #include <linux/module.h>
>  #include <linux/of.h>
>  #include <linux/of_device.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/reset.h>
>  #include <linux/sizes.h>
>  
> @@ -548,9 +549,13 @@ static int dwcmshc_probe(struct platform_device *pdev)
>  
>  	host->mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
>  
> +	pm_runtime_get_noresume(dev);
> +	pm_runtime_set_active(dev);
> +	pm_runtime_enable(dev);
> +
>  	err = sdhci_setup_host(host);
>  	if (err)
> -		goto err_clk;
> +		goto err_rpm;
>  
>  	if (rk_priv)
>  		dwcmshc_rk35xx_postinit(host, priv);
> @@ -559,10 +564,15 @@ static int dwcmshc_probe(struct platform_device *pdev)
>  	if (err)
>  		goto err_setup_host;
>  
> +	pm_runtime_put(dev);
> +
>  	return 0;
>  
>  err_setup_host:
>  	sdhci_cleanup_host(host);
> +err_rpm:
> +	pm_runtime_disable(dev);
> +	pm_runtime_put_noidle(dev);
>  err_clk:
>  	clk_disable_unprepare(pltfm_host->clk);
>  	clk_disable_unprepare(priv->bus_clk);
> @@ -594,6 +604,10 @@ static int dwcmshc_remove(struct platform_device *pdev)
>  }
>  
>  #ifdef CONFIG_PM_SLEEP
> +/*
> + * Note, runtime suspend changes only SDHCI_CLOCK_CARD_EN which has no effect on
> + * system suspend.
> + */

This comment isn't needed since pm_runtime_get_sync() will
always runtime resume the device if needed.

>  static int dwcmshc_suspend(struct device *dev)
>  {
>  	struct sdhci_host *host = dev_get_drvdata(dev);
> @@ -602,9 +616,11 @@ static int dwcmshc_suspend(struct device *dev)
>  	struct rk35xx_priv *rk_priv = priv->priv;
>  	int ret;
>  
> +	pm_runtime_get_sync(dev);

This needs a corresponding pm_runtime_put() at the end of dwcmshc_resume().

> +
>  	ret = sdhci_suspend_host(host);
>  	if (ret)
> -		return ret;
> +		goto err_suspend;
>  
>  	clk_disable_unprepare(pltfm_host->clk);
>  	if (!IS_ERR(priv->bus_clk))
> @@ -614,9 +630,15 @@ static int dwcmshc_suspend(struct device *dev)
>  		clk_bulk_disable_unprepare(RK35xx_MAX_CLKS,
>  					   rk_priv->rockchip_clks);
>  
> +err_suspend:
> +	pm_runtime_put_noidle(dev);
>  	return ret;
>  }
>  
> +/*
> + * Note, system resume leaves SDHCI_CLOCK_INT_EN off which is consistent with
> + * either runtime suspended or runtime resumed.
> + */

As above, this comment isn't needed.

>  static int dwcmshc_resume(struct device *dev)


As mentioned above, dwcmshc_resume() needs a pm_runtime_put()
to balance the pm_runtime_get_sync().

Could fix up the error path too, but that should be a
separate prior patch.

Probably end up looking like:


diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
index 20aa9b6327d2..c9b020b7a3f6 100644
--- a/drivers/mmc/host/sdhci-of-dwcmshc.c
+++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
@@ -652,17 +652,33 @@ static int dwcmshc_resume(struct device *dev)
 	if (!IS_ERR(priv->bus_clk)) {
 		ret = clk_prepare_enable(priv->bus_clk);
 		if (ret)
-			return ret;
+			goto disable_clk;
 	}
 
 	if (rk_priv) {
 		ret = clk_bulk_prepare_enable(RK35xx_MAX_CLKS,
 					      rk_priv->rockchip_clks);
 		if (ret)
-			return ret;
+			goto disable_bus_clk;
 	}
 
-	return sdhci_resume_host(host);
+	ret = sdhci_resume_host(host);
+	if (ret)
+		goto disable_rockchip_clks;
+
+	pm_runtime_put(dev);
+
+	return 0;
+
+disable_rockchip_clks:
+	if (rk_priv)
+		clk_bulk_disable_unprepare(RK35xx_MAX_CLKS, rk_priv->rockchip_clks);
+disable_bus_clk:
+	if (!IS_ERR(priv->bus_clk))
+		clk_disable_unprepare(priv->bus_clk);
+disable_clk:
+	clk_disable_unprepare(pltfm_host->clk);
+	return ret;
 }
 #endif
 



>  {
>  	struct sdhci_host *host = dev_get_drvdata(dev);
> @@ -646,7 +668,55 @@ static int dwcmshc_resume(struct device *dev)
>  }
>  #endif
>  
> -static SIMPLE_DEV_PM_OPS(dwcmshc_pmops, dwcmshc_suspend, dwcmshc_resume);
> +#ifdef CONFIG_PM
> +
> +static void dwcmshc_enable_card_clk(struct sdhci_host *host)
> +{
> +	u16 ctrl;
> +
> +	ctrl = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> +	if ((ctrl & SDHCI_CLOCK_INT_EN) && !(ctrl & SDHCI_CLOCK_CARD_EN)) {
> +		ctrl |= SDHCI_CLOCK_CARD_EN;
> +		sdhci_writew(host, ctrl, SDHCI_CLOCK_CONTROL);
> +	}
> +}
> +
> +static void dwcmshc_disable_card_clk(struct sdhci_host *host)
> +{
> +	u16 ctrl;
> +
> +	ctrl = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> +	if (ctrl & SDHCI_CLOCK_CARD_EN) {
> +		ctrl &= ~SDHCI_CLOCK_CARD_EN;
> +		sdhci_writew(host, ctrl, SDHCI_CLOCK_CONTROL);
> +	}
> +}
> +
> +static int dwcmshc_runtime_suspend(struct device *dev)
> +{
> +	struct sdhci_host *host = dev_get_drvdata(dev);
> +
> +	dwcmshc_disable_card_clk(host);
> +
> +	return 0;
> +}
> +
> +static int dwcmshc_runtime_resume(struct device *dev)
> +{
> +	struct sdhci_host *host = dev_get_drvdata(dev);
> +
> +	dwcmshc_enable_card_clk(host);
> +
> +	return 0;
> +}
> +
> +#endif
> +
> +static const struct dev_pm_ops dwcmshc_pmops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(dwcmshc_suspend, dwcmshc_resume)
> +	SET_RUNTIME_PM_OPS(dwcmshc_runtime_suspend,
> +			   dwcmshc_runtime_resume, NULL)
> +};
>  
>  static struct platform_driver sdhci_dwcmshc_driver = {
>  	.driver	= {
Liming Sun Aug. 17, 2023, 4:22 p.m. UTC | #4 
> -----Original Message-----
> From: Adrian Hunter <adrian.hunter@intel.com>
> Sent: Thursday, August 17, 2023 3:36 AM
> To: Liming Sun <limings@nvidia.com>; Ulf Hansson <ulf.hansson@linaro.org>;
> David Thompson <davthompson@nvidia.com>; Shawn Lin <shawn.lin@rock-
> chips.com>
> Cc: linux-mmc@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH v8] mmc: sdhci-of-dwcmshc: Add runtime PM operations
> 
> On 17/08/23 04:06, Liming Sun wrote:
> > This commit implements the runtime PM operations to disable eMMC
> > card clock when idle.
> >
> > Reviewed-by: David Thompson <davthompson@nvidia.com>
> > Signed-off-by: Liming Sun <limings@nvidia.com>
> > ---
> > v7->v8:
> >     - Address Ulf's comment (option-1);
> >     - Updates for Adrian;s comment to remove the force_suspend/resume
> >       in dwcmshc_resume()/dwcmshc_suspend(); Add comments for
> >       dwcmshc_resume()/dwcmshc_suspend();
> > v6->v7:
> >     - Address Ulf's comment;
> > v5->v6:
> >     - Address Adrian's more comments and add coordination between
> >       runtime PM and system PM;
> > v4->v5:
> >     - Address Adrian's comment to move the pm_enable to the end to
> >       avoid race;
> > v3->v4:
> >     - Fix compiling reported by 'kernel test robot';
> > v2->v3:
> >     - Revise the commit message;
> > v1->v2:
> >     Updates for comments from Ulf:
> >     - Make the runtime PM logic generic for sdhci-of-dwcmshc;
> > v1: Initial version.
> > ---
> >  drivers/mmc/host/sdhci-of-dwcmshc.c | 76
> +++++++++++++++++++++++++++--
> >  1 file changed, 73 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-
> of-dwcmshc.c
> > index e68cd87998c8..2196218c9d79 100644
> > --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
> > +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
> > @@ -15,6 +15,7 @@
> >  #include <linux/module.h>
> >  #include <linux/of.h>
> >  #include <linux/of_device.h>
> > +#include <linux/pm_runtime.h>
> >  #include <linux/reset.h>
> >  #include <linux/sizes.h>
> >
> > @@ -548,9 +549,13 @@ static int dwcmshc_probe(struct platform_device
> *pdev)
> >
> >  	host->mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
> >
> > +	pm_runtime_get_noresume(dev);
> > +	pm_runtime_set_active(dev);
> > +	pm_runtime_enable(dev);
> > +
> >  	err = sdhci_setup_host(host);
> >  	if (err)
> > -		goto err_clk;
> > +		goto err_rpm;
> >
> >  	if (rk_priv)
> >  		dwcmshc_rk35xx_postinit(host, priv);
> > @@ -559,10 +564,15 @@ static int dwcmshc_probe(struct platform_device
> *pdev)
> >  	if (err)
> >  		goto err_setup_host;
> >
> > +	pm_runtime_put(dev);
> > +
> >  	return 0;
> >
> >  err_setup_host:
> >  	sdhci_cleanup_host(host);
> > +err_rpm:
> > +	pm_runtime_disable(dev);
> > +	pm_runtime_put_noidle(dev);
> >  err_clk:
> >  	clk_disable_unprepare(pltfm_host->clk);
> >  	clk_disable_unprepare(priv->bus_clk);
> > @@ -594,6 +604,10 @@ static int dwcmshc_remove(struct platform_device
> *pdev)
> >  }
> >
> >  #ifdef CONFIG_PM_SLEEP
> > +/*
> > + * Note, runtime suspend changes only SDHCI_CLOCK_CARD_EN which has
> no effect on
> > + * system suspend.
> > + */
> 
> This comment isn't needed since pm_runtime_get_sync() will
> always runtime resume the device if needed.

Updated in v9.

> 
> >  static int dwcmshc_suspend(struct device *dev)
> >  {
> >  	struct sdhci_host *host = dev_get_drvdata(dev);
> > @@ -602,9 +616,11 @@ static int dwcmshc_suspend(struct device *dev)
> >  	struct rk35xx_priv *rk_priv = priv->priv;
> >  	int ret;
> >
> > +	pm_runtime_get_sync(dev);
> 
> This needs a corresponding pm_runtime_put() at the end of
> dwcmshc_resume().

Updated in v9.

> 
> > +
> >  	ret = sdhci_suspend_host(host);
> >  	if (ret)
> > -		return ret;
> > +		goto err_suspend;
> >
> >  	clk_disable_unprepare(pltfm_host->clk);
> >  	if (!IS_ERR(priv->bus_clk))
> > @@ -614,9 +630,15 @@ static int dwcmshc_suspend(struct device *dev)
> >  		clk_bulk_disable_unprepare(RK35xx_MAX_CLKS,
> >  					   rk_priv->rockchip_clks);
> >
> > +err_suspend:
> > +	pm_runtime_put_noidle(dev);
> >  	return ret;
> >  }
> >
> > +/*
> > + * Note, system resume leaves SDHCI_CLOCK_INT_EN off which is consistent
> with
> > + * either runtime suspended or runtime resumed.
> > + */
> 
> As above, this comment isn't needed.

Updated in v9.

> 
> >  static int dwcmshc_resume(struct device *dev)
> 
> 
> As mentioned above, dwcmshc_resume() needs a pm_runtime_put()
> to balance the pm_runtime_get_sync().

Updated in v9.

> 
> Could fix up the error path too, but that should be a
> separate prior patch.
> 
> Probably end up looking like:
> 
> 
> diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-
> of-dwcmshc.c
> index 20aa9b6327d2..c9b020b7a3f6 100644
> --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
> +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
> @@ -652,17 +652,33 @@ static int dwcmshc_resume(struct device *dev)
>  	if (!IS_ERR(priv->bus_clk)) {
>  		ret = clk_prepare_enable(priv->bus_clk);
>  		if (ret)
> -			return ret;
> +			goto disable_clk;
>  	}
> 
>  	if (rk_priv) {
>  		ret = clk_bulk_prepare_enable(RK35xx_MAX_CLKS,
>  					      rk_priv->rockchip_clks);
>  		if (ret)
> -			return ret;
> +			goto disable_bus_clk;
>  	}
> 
> -	return sdhci_resume_host(host);
> +	ret = sdhci_resume_host(host);
> +	if (ret)
> +		goto disable_rockchip_clks;
> +
> +	pm_runtime_put(dev);
> +
> +	return 0;
> +
> +disable_rockchip_clks:
> +	if (rk_priv)
> +		clk_bulk_disable_unprepare(RK35xx_MAX_CLKS, rk_priv-
> >rockchip_clks);
> +disable_bus_clk:
> +	if (!IS_ERR(priv->bus_clk))
> +		clk_disable_unprepare(priv->bus_clk);
> +disable_clk:
> +	clk_disable_unprepare(pltfm_host->clk);
> +	return ret;
>  }
>  #endif
> 
> 

Do you mean a separate 'post' patch? I left it out in v9 and could post another one for this error path. Or do you prefer the same patch series?

> 
> 
> >  {
> >  	struct sdhci_host *host = dev_get_drvdata(dev);
> > @@ -646,7 +668,55 @@ static int dwcmshc_resume(struct device *dev)
> >  }
> >  #endif
> >
> > -static SIMPLE_DEV_PM_OPS(dwcmshc_pmops, dwcmshc_suspend,
> dwcmshc_resume);
> > +#ifdef CONFIG_PM
> > +
> > +static void dwcmshc_enable_card_clk(struct sdhci_host *host)
> > +{
> > +	u16 ctrl;
> > +
> > +	ctrl = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> > +	if ((ctrl & SDHCI_CLOCK_INT_EN) && !(ctrl &
> SDHCI_CLOCK_CARD_EN)) {
> > +		ctrl |= SDHCI_CLOCK_CARD_EN;
> > +		sdhci_writew(host, ctrl, SDHCI_CLOCK_CONTROL);
> > +	}
> > +}
> > +
> > +static void dwcmshc_disable_card_clk(struct sdhci_host *host)
> > +{
> > +	u16 ctrl;
> > +
> > +	ctrl = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> > +	if (ctrl & SDHCI_CLOCK_CARD_EN) {
> > +		ctrl &= ~SDHCI_CLOCK_CARD_EN;
> > +		sdhci_writew(host, ctrl, SDHCI_CLOCK_CONTROL);
> > +	}
> > +}
> > +
> > +static int dwcmshc_runtime_suspend(struct device *dev)
> > +{
> > +	struct sdhci_host *host = dev_get_drvdata(dev);
> > +
> > +	dwcmshc_disable_card_clk(host);
> > +
> > +	return 0;
> > +}
> > +
> > +static int dwcmshc_runtime_resume(struct device *dev)
> > +{
> > +	struct sdhci_host *host = dev_get_drvdata(dev);
> > +
> > +	dwcmshc_enable_card_clk(host);
> > +
> > +	return 0;
> > +}
> > +
> > +#endif
> > +
> > +static const struct dev_pm_ops dwcmshc_pmops = {
> > +	SET_SYSTEM_SLEEP_PM_OPS(dwcmshc_suspend, dwcmshc_resume)
> > +	SET_RUNTIME_PM_OPS(dwcmshc_runtime_suspend,
> > +			   dwcmshc_runtime_resume, NULL)
> > +};
> >
> >  static struct platform_driver sdhci_dwcmshc_driver = {
> >  	.driver	= {
Adrian Hunter Aug. 18, 2023, 7:27 a.m. UTC | #5 
On 17/08/23 19:22, Liming Sun wrote:
> 
> 
>> -----Original Message-----
>> From: Adrian Hunter <adrian.hunter@intel.com>
>> Sent: Thursday, August 17, 2023 3:36 AM
>> To: Liming Sun <limings@nvidia.com>; Ulf Hansson <ulf.hansson@linaro.org>;
>> David Thompson <davthompson@nvidia.com>; Shawn Lin <shawn.lin@rock-
>> chips.com>
>> Cc: linux-mmc@vger.kernel.org; linux-kernel@vger.kernel.org
>> Subject: Re: [PATCH v8] mmc: sdhci-of-dwcmshc: Add runtime PM operations
>>
>> On 17/08/23 04:06, Liming Sun wrote:
>>> This commit implements the runtime PM operations to disable eMMC
>>> card clock when idle.
>>>
>>> Reviewed-by: David Thompson <davthompson@nvidia.com>
>>> Signed-off-by: Liming Sun <limings@nvidia.com>
>>> ---
>>> v7->v8:
>>>     - Address Ulf's comment (option-1);
>>>     - Updates for Adrian;s comment to remove the force_suspend/resume
>>>       in dwcmshc_resume()/dwcmshc_suspend(); Add comments for
>>>       dwcmshc_resume()/dwcmshc_suspend();
>>> v6->v7:
>>>     - Address Ulf's comment;
>>> v5->v6:
>>>     - Address Adrian's more comments and add coordination between
>>>       runtime PM and system PM;
>>> v4->v5:
>>>     - Address Adrian's comment to move the pm_enable to the end to
>>>       avoid race;
>>> v3->v4:
>>>     - Fix compiling reported by 'kernel test robot';
>>> v2->v3:
>>>     - Revise the commit message;
>>> v1->v2:
>>>     Updates for comments from Ulf:
>>>     - Make the runtime PM logic generic for sdhci-of-dwcmshc;
>>> v1: Initial version.
>>> ---
>>>  drivers/mmc/host/sdhci-of-dwcmshc.c | 76
>> +++++++++++++++++++++++++++--
>>>  1 file changed, 73 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-
>> of-dwcmshc.c
>>> index e68cd87998c8..2196218c9d79 100644
>>> --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
>>> +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
>>> @@ -15,6 +15,7 @@
>>>  #include <linux/module.h>
>>>  #include <linux/of.h>
>>>  #include <linux/of_device.h>
>>> +#include <linux/pm_runtime.h>
>>>  #include <linux/reset.h>
>>>  #include <linux/sizes.h>
>>>
>>> @@ -548,9 +549,13 @@ static int dwcmshc_probe(struct platform_device
>> *pdev)
>>>
>>>  	host->mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
>>>
>>> +	pm_runtime_get_noresume(dev);
>>> +	pm_runtime_set_active(dev);
>>> +	pm_runtime_enable(dev);
>>> +
>>>  	err = sdhci_setup_host(host);
>>>  	if (err)
>>> -		goto err_clk;
>>> +		goto err_rpm;
>>>
>>>  	if (rk_priv)
>>>  		dwcmshc_rk35xx_postinit(host, priv);
>>> @@ -559,10 +564,15 @@ static int dwcmshc_probe(struct platform_device
>> *pdev)
>>>  	if (err)
>>>  		goto err_setup_host;
>>>
>>> +	pm_runtime_put(dev);
>>> +
>>>  	return 0;
>>>
>>>  err_setup_host:
>>>  	sdhci_cleanup_host(host);
>>> +err_rpm:
>>> +	pm_runtime_disable(dev);
>>> +	pm_runtime_put_noidle(dev);
>>>  err_clk:
>>>  	clk_disable_unprepare(pltfm_host->clk);
>>>  	clk_disable_unprepare(priv->bus_clk);
>>> @@ -594,6 +604,10 @@ static int dwcmshc_remove(struct platform_device
>> *pdev)
>>>  }
>>>
>>>  #ifdef CONFIG_PM_SLEEP
>>> +/*
>>> + * Note, runtime suspend changes only SDHCI_CLOCK_CARD_EN which has
>> no effect on
>>> + * system suspend.
>>> + */
>>
>> This comment isn't needed since pm_runtime_get_sync() will
>> always runtime resume the device if needed.
> 
> Updated in v9.
> 
>>
>>>  static int dwcmshc_suspend(struct device *dev)
>>>  {
>>>  	struct sdhci_host *host = dev_get_drvdata(dev);
>>> @@ -602,9 +616,11 @@ static int dwcmshc_suspend(struct device *dev)
>>>  	struct rk35xx_priv *rk_priv = priv->priv;
>>>  	int ret;
>>>
>>> +	pm_runtime_get_sync(dev);
>>
>> This needs a corresponding pm_runtime_put() at the end of
>> dwcmshc_resume().
> 
> Updated in v9.
> 
>>
>>> +
>>>  	ret = sdhci_suspend_host(host);
>>>  	if (ret)
>>> -		return ret;
>>> +		goto err_suspend;
>>>
>>>  	clk_disable_unprepare(pltfm_host->clk);
>>>  	if (!IS_ERR(priv->bus_clk))
>>> @@ -614,9 +630,15 @@ static int dwcmshc_suspend(struct device *dev)
>>>  		clk_bulk_disable_unprepare(RK35xx_MAX_CLKS,
>>>  					   rk_priv->rockchip_clks);
>>>
>>> +err_suspend:
>>> +	pm_runtime_put_noidle(dev);
>>>  	return ret;
>>>  }
>>>
>>> +/*
>>> + * Note, system resume leaves SDHCI_CLOCK_INT_EN off which is consistent
>> with
>>> + * either runtime suspended or runtime resumed.
>>> + */
>>
>> As above, this comment isn't needed.
> 
> Updated in v9.
> 
>>
>>>  static int dwcmshc_resume(struct device *dev)
>>
>>
>> As mentioned above, dwcmshc_resume() needs a pm_runtime_put()
>> to balance the pm_runtime_get_sync().
> 
> Updated in v9.
> 
>>
>> Could fix up the error path too, but that should be a
>> separate prior patch.
>>
>> Probably end up looking like:
>>
>>
>> diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-
>> of-dwcmshc.c
>> index 20aa9b6327d2..c9b020b7a3f6 100644
>> --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
>> +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
>> @@ -652,17 +652,33 @@ static int dwcmshc_resume(struct device *dev)
>>  	if (!IS_ERR(priv->bus_clk)) {
>>  		ret = clk_prepare_enable(priv->bus_clk);
>>  		if (ret)
>> -			return ret;
>> +			goto disable_clk;
>>  	}
>>
>>  	if (rk_priv) {
>>  		ret = clk_bulk_prepare_enable(RK35xx_MAX_CLKS,
>>  					      rk_priv->rockchip_clks);
>>  		if (ret)
>> -			return ret;
>> +			goto disable_bus_clk;
>>  	}
>>
>> -	return sdhci_resume_host(host);
>> +	ret = sdhci_resume_host(host);
>> +	if (ret)
>> +		goto disable_rockchip_clks;
>> +
>> +	pm_runtime_put(dev);
>> +
>> +	return 0;
>> +
>> +disable_rockchip_clks:
>> +	if (rk_priv)
>> +		clk_bulk_disable_unprepare(RK35xx_MAX_CLKS, rk_priv-
>>> rockchip_clks);
>> +disable_bus_clk:
>> +	if (!IS_ERR(priv->bus_clk))
>> +		clk_disable_unprepare(priv->bus_clk);
>> +disable_clk:
>> +	clk_disable_unprepare(pltfm_host->clk);
>> +	return ret;
>>  }
>>  #endif
>>
>>
> 
> Do you mean a separate 'post' patch? I left it out in v9 and could post another one for this error path. Or do you prefer the same patch series?

Same patch series, 2 patches.  First patch fixes the error paths in dwcmshc_resume().
Second patch adds runtime pm.

> 
>>
>>
>>>  {
>>>  	struct sdhci_host *host = dev_get_drvdata(dev);
>>> @@ -646,7 +668,55 @@ static int dwcmshc_resume(struct device *dev)
>>>  }
>>>  #endif
>>>
>>> -static SIMPLE_DEV_PM_OPS(dwcmshc_pmops, dwcmshc_suspend,
>> dwcmshc_resume);
>>> +#ifdef CONFIG_PM
>>> +
>>> +static void dwcmshc_enable_card_clk(struct sdhci_host *host)
>>> +{
>>> +	u16 ctrl;
>>> +
>>> +	ctrl = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
>>> +	if ((ctrl & SDHCI_CLOCK_INT_EN) && !(ctrl &
>> SDHCI_CLOCK_CARD_EN)) {
>>> +		ctrl |= SDHCI_CLOCK_CARD_EN;
>>> +		sdhci_writew(host, ctrl, SDHCI_CLOCK_CONTROL);
>>> +	}
>>> +}
>>> +
>>> +static void dwcmshc_disable_card_clk(struct sdhci_host *host)
>>> +{
>>> +	u16 ctrl;
>>> +
>>> +	ctrl = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
>>> +	if (ctrl & SDHCI_CLOCK_CARD_EN) {
>>> +		ctrl &= ~SDHCI_CLOCK_CARD_EN;
>>> +		sdhci_writew(host, ctrl, SDHCI_CLOCK_CONTROL);
>>> +	}
>>> +}
>>> +
>>> +static int dwcmshc_runtime_suspend(struct device *dev)
>>> +{
>>> +	struct sdhci_host *host = dev_get_drvdata(dev);
>>> +
>>> +	dwcmshc_disable_card_clk(host);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static int dwcmshc_runtime_resume(struct device *dev)
>>> +{
>>> +	struct sdhci_host *host = dev_get_drvdata(dev);
>>> +
>>> +	dwcmshc_enable_card_clk(host);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +#endif
>>> +
>>> +static const struct dev_pm_ops dwcmshc_pmops = {
>>> +	SET_SYSTEM_SLEEP_PM_OPS(dwcmshc_suspend, dwcmshc_resume)
>>> +	SET_RUNTIME_PM_OPS(dwcmshc_runtime_suspend,
>>> +			   dwcmshc_runtime_resume, NULL)
>>> +};
>>>
>>>  static struct platform_driver sdhci_dwcmshc_driver = {
>>>  	.driver	= {
>
Ulf Hansson Aug. 18, 2023, 9 a.m. UTC | #6 
On Thu, 17 Aug 2023 at 18:22, Liming Sun <limings@nvidia.com> wrote:
>
> This commit implements the runtime PM operations to disable eMMC
> card clock when idle.
>
> Reviewed-by: David Thompson <davthompson@nvidia.com>
> Signed-off-by: Liming Sun <limings@nvidia.com>
> ---
> v8->v9:
>     - Address Adrian's comment to do the pm_runtime_put() in
>       dwcmshc_resume() instead; Error path changes not included yet.
> v7->v8:
>     - Address Ulf's comment (option-1);
>     - Updates for Adrian's comment to remove the force_suspend/resume
>       in dwcmshc_resume()/dwcmshc_suspend(); Add comments for
>       dwcmshc_resume()/dwcmshc_suspend();
> v6->v7:
>     - Address Ulf's comment;
> v5->v6:
>     - Address Adrian's more comments and add coordination between
>       runtime PM and system PM;
> v4->v5:
>     - Address Adrian's comment to move the pm_enable to the end to
>       avoid race;
> v3->v4:
>     - Fix compiling reported by 'kernel test robot';
> v2->v3:
>     - Revise the commit message;
> v1->v2:
>     Updates for comments from Ulf:
>     - Make the runtime PM logic generic for sdhci-of-dwcmshc;
> v1: Initial version.
> ---
>  drivers/mmc/host/sdhci-of-dwcmshc.c | 76 +++++++++++++++++++++++++++--
>  1 file changed, 72 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
> index e68cd87998c8..3b40f55ce2a4 100644
> --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
> +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
> @@ -15,6 +15,7 @@
>  #include <linux/module.h>
>  #include <linux/of.h>
>  #include <linux/of_device.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/reset.h>
>  #include <linux/sizes.h>
>
> @@ -548,9 +549,13 @@ static int dwcmshc_probe(struct platform_device *pdev)
>
>         host->mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
>
> +       pm_runtime_get_noresume(dev);
> +       pm_runtime_set_active(dev);
> +       pm_runtime_enable(dev);
> +
>         err = sdhci_setup_host(host);
>         if (err)
> -               goto err_clk;
> +               goto err_rpm;
>
>         if (rk_priv)
>                 dwcmshc_rk35xx_postinit(host, priv);
> @@ -559,10 +564,15 @@ static int dwcmshc_probe(struct platform_device *pdev)
>         if (err)
>                 goto err_setup_host;
>
> +       pm_runtime_put(dev);
> +
>         return 0;
>
>  err_setup_host:
>         sdhci_cleanup_host(host);
> +err_rpm:
> +       pm_runtime_disable(dev);
> +       pm_runtime_put_noidle(dev);
>  err_clk:
>         clk_disable_unprepare(pltfm_host->clk);
>         clk_disable_unprepare(priv->bus_clk);
> @@ -602,9 +612,13 @@ static int dwcmshc_suspend(struct device *dev)
>         struct rk35xx_priv *rk_priv = priv->priv;
>         int ret;
>
> +       pm_runtime_get_sync(dev);
> +
>         ret = sdhci_suspend_host(host);
> -       if (ret)
> +       if (ret) {
> +               pm_runtime_put(dev);
>                 return ret;
> +       }
>
>         clk_disable_unprepare(pltfm_host->clk);
>         if (!IS_ERR(priv->bus_clk))
> @@ -642,11 +656,65 @@ static int dwcmshc_resume(struct device *dev)
>                         return ret;
>         }
>
> -       return sdhci_resume_host(host);
> +       ret = sdhci_resume_host(host);
> +       if (ret)
> +               return ret;
> +
> +       pm_runtime_put(dev);

To simplify the error path, I would suggest that you move the call to
pm_runtime_put() to dwcmshc_suspend(). In fact what you need is just a
call to pm_runtime_put_noidle(), somewhere after the call to
pm_runtime_get_sync().

This is because runtime suspend is prevented by the PM core as it
bumps the usage count with a pm_runtime_get_noresume() in the
device_prepare() phase.

> +
> +       return 0;
>  }
>  #endif

[...]

Kind regards
Uffe
Adrian Hunter Aug. 18, 2023, 9:35 a.m. UTC | #7 
On 18/08/23 12:00, Ulf Hansson wrote:
> On Thu, 17 Aug 2023 at 18:22, Liming Sun <limings@nvidia.com> wrote:
>>
>> This commit implements the runtime PM operations to disable eMMC
>> card clock when idle.
>>
>> Reviewed-by: David Thompson <davthompson@nvidia.com>
>> Signed-off-by: Liming Sun <limings@nvidia.com>
>> ---
>> v8->v9:
>>     - Address Adrian's comment to do the pm_runtime_put() in
>>       dwcmshc_resume() instead; Error path changes not included yet.
>> v7->v8:
>>     - Address Ulf's comment (option-1);
>>     - Updates for Adrian's comment to remove the force_suspend/resume
>>       in dwcmshc_resume()/dwcmshc_suspend(); Add comments for
>>       dwcmshc_resume()/dwcmshc_suspend();
>> v6->v7:
>>     - Address Ulf's comment;
>> v5->v6:
>>     - Address Adrian's more comments and add coordination between
>>       runtime PM and system PM;
>> v4->v5:
>>     - Address Adrian's comment to move the pm_enable to the end to
>>       avoid race;
>> v3->v4:
>>     - Fix compiling reported by 'kernel test robot';
>> v2->v3:
>>     - Revise the commit message;
>> v1->v2:
>>     Updates for comments from Ulf:
>>     - Make the runtime PM logic generic for sdhci-of-dwcmshc;
>> v1: Initial version.
>> ---
>>  drivers/mmc/host/sdhci-of-dwcmshc.c | 76 +++++++++++++++++++++++++++--
>>  1 file changed, 72 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
>> index e68cd87998c8..3b40f55ce2a4 100644
>> --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
>> +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
>> @@ -15,6 +15,7 @@
>>  #include <linux/module.h>
>>  #include <linux/of.h>
>>  #include <linux/of_device.h>
>> +#include <linux/pm_runtime.h>
>>  #include <linux/reset.h>
>>  #include <linux/sizes.h>
>>
>> @@ -548,9 +549,13 @@ static int dwcmshc_probe(struct platform_device *pdev)
>>
>>         host->mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
>>
>> +       pm_runtime_get_noresume(dev);
>> +       pm_runtime_set_active(dev);
>> +       pm_runtime_enable(dev);
>> +
>>         err = sdhci_setup_host(host);
>>         if (err)
>> -               goto err_clk;
>> +               goto err_rpm;
>>
>>         if (rk_priv)
>>                 dwcmshc_rk35xx_postinit(host, priv);
>> @@ -559,10 +564,15 @@ static int dwcmshc_probe(struct platform_device *pdev)
>>         if (err)
>>                 goto err_setup_host;
>>
>> +       pm_runtime_put(dev);
>> +
>>         return 0;
>>
>>  err_setup_host:
>>         sdhci_cleanup_host(host);
>> +err_rpm:
>> +       pm_runtime_disable(dev);
>> +       pm_runtime_put_noidle(dev);
>>  err_clk:
>>         clk_disable_unprepare(pltfm_host->clk);
>>         clk_disable_unprepare(priv->bus_clk);
>> @@ -602,9 +612,13 @@ static int dwcmshc_suspend(struct device *dev)
>>         struct rk35xx_priv *rk_priv = priv->priv;
>>         int ret;
>>
>> +       pm_runtime_get_sync(dev);
>> +
>>         ret = sdhci_suspend_host(host);
>> -       if (ret)
>> +       if (ret) {
>> +               pm_runtime_put(dev);
>>                 return ret;
>> +       }
>>
>>         clk_disable_unprepare(pltfm_host->clk);
>>         if (!IS_ERR(priv->bus_clk))
>> @@ -642,11 +656,65 @@ static int dwcmshc_resume(struct device *dev)
>>                         return ret;
>>         }
>>
>> -       return sdhci_resume_host(host);
>> +       ret = sdhci_resume_host(host);
>> +       if (ret)
>> +               return ret;
>> +
>> +       pm_runtime_put(dev);
> 
> To simplify the error path, I would suggest that you move the call to
> pm_runtime_put() to dwcmshc_suspend(). In fact what you need is just a
> call to pm_runtime_put_noidle(), somewhere after the call to
> pm_runtime_get_sync().
> 
> This is because runtime suspend is prevented by the PM core as it
> bumps the usage count with a pm_runtime_get_noresume() in the
> device_prepare() phase.

I thought you didn't want to assume that, because in that case
it can just be pm_runtime_resume() instead of pm_runtime_get_sync(),
and then no 'put' is needed at all.

> 
>> +
>> +       return 0;
>>  }
>>  #endif
> 
> [...]
> 
> Kind regards
> Uffe
Ulf Hansson Aug. 18, 2023, 10:19 a.m. UTC | #8 
On Fri, 18 Aug 2023 at 11:36, Adrian Hunter <adrian.hunter@intel.com> wrote:
>
> On 18/08/23 12:00, Ulf Hansson wrote:
> > On Thu, 17 Aug 2023 at 18:22, Liming Sun <limings@nvidia.com> wrote:
> >>
> >> This commit implements the runtime PM operations to disable eMMC
> >> card clock when idle.
> >>
> >> Reviewed-by: David Thompson <davthompson@nvidia.com>
> >> Signed-off-by: Liming Sun <limings@nvidia.com>
> >> ---
> >> v8->v9:
> >>     - Address Adrian's comment to do the pm_runtime_put() in
> >>       dwcmshc_resume() instead; Error path changes not included yet.
> >> v7->v8:
> >>     - Address Ulf's comment (option-1);
> >>     - Updates for Adrian's comment to remove the force_suspend/resume
> >>       in dwcmshc_resume()/dwcmshc_suspend(); Add comments for
> >>       dwcmshc_resume()/dwcmshc_suspend();
> >> v6->v7:
> >>     - Address Ulf's comment;
> >> v5->v6:
> >>     - Address Adrian's more comments and add coordination between
> >>       runtime PM and system PM;
> >> v4->v5:
> >>     - Address Adrian's comment to move the pm_enable to the end to
> >>       avoid race;
> >> v3->v4:
> >>     - Fix compiling reported by 'kernel test robot';
> >> v2->v3:
> >>     - Revise the commit message;
> >> v1->v2:
> >>     Updates for comments from Ulf:
> >>     - Make the runtime PM logic generic for sdhci-of-dwcmshc;
> >> v1: Initial version.
> >> ---
> >>  drivers/mmc/host/sdhci-of-dwcmshc.c | 76 +++++++++++++++++++++++++++--
> >>  1 file changed, 72 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
> >> index e68cd87998c8..3b40f55ce2a4 100644
> >> --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
> >> +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
> >> @@ -15,6 +15,7 @@
> >>  #include <linux/module.h>
> >>  #include <linux/of.h>
> >>  #include <linux/of_device.h>
> >> +#include <linux/pm_runtime.h>
> >>  #include <linux/reset.h>
> >>  #include <linux/sizes.h>
> >>
> >> @@ -548,9 +549,13 @@ static int dwcmshc_probe(struct platform_device *pdev)
> >>
> >>         host->mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
> >>
> >> +       pm_runtime_get_noresume(dev);
> >> +       pm_runtime_set_active(dev);
> >> +       pm_runtime_enable(dev);
> >> +
> >>         err = sdhci_setup_host(host);
> >>         if (err)
> >> -               goto err_clk;
> >> +               goto err_rpm;
> >>
> >>         if (rk_priv)
> >>                 dwcmshc_rk35xx_postinit(host, priv);
> >> @@ -559,10 +564,15 @@ static int dwcmshc_probe(struct platform_device *pdev)
> >>         if (err)
> >>                 goto err_setup_host;
> >>
> >> +       pm_runtime_put(dev);
> >> +
> >>         return 0;
> >>
> >>  err_setup_host:
> >>         sdhci_cleanup_host(host);
> >> +err_rpm:
> >> +       pm_runtime_disable(dev);
> >> +       pm_runtime_put_noidle(dev);
> >>  err_clk:
> >>         clk_disable_unprepare(pltfm_host->clk);
> >>         clk_disable_unprepare(priv->bus_clk);
> >> @@ -602,9 +612,13 @@ static int dwcmshc_suspend(struct device *dev)
> >>         struct rk35xx_priv *rk_priv = priv->priv;
> >>         int ret;
> >>
> >> +       pm_runtime_get_sync(dev);
> >> +
> >>         ret = sdhci_suspend_host(host);
> >> -       if (ret)
> >> +       if (ret) {
> >> +               pm_runtime_put(dev);
> >>                 return ret;
> >> +       }
> >>
> >>         clk_disable_unprepare(pltfm_host->clk);
> >>         if (!IS_ERR(priv->bus_clk))
> >> @@ -642,11 +656,65 @@ static int dwcmshc_resume(struct device *dev)
> >>                         return ret;
> >>         }
> >>
> >> -       return sdhci_resume_host(host);
> >> +       ret = sdhci_resume_host(host);
> >> +       if (ret)
> >> +               return ret;
> >> +
> >> +       pm_runtime_put(dev);
> >
> > To simplify the error path, I would suggest that you move the call to
> > pm_runtime_put() to dwcmshc_suspend(). In fact what you need is just a
> > call to pm_runtime_put_noidle(), somewhere after the call to
> > pm_runtime_get_sync().
> >
> > This is because runtime suspend is prevented by the PM core as it
> > bumps the usage count with a pm_runtime_get_noresume() in the
> > device_prepare() phase.
>
> I thought you didn't want to assume that, because in that case
> it can just be pm_runtime_resume() instead of pm_runtime_get_sync(),
> and then no 'put' is needed at all.

I don't really care, but just wanted to keep it as simple as possible.

So yes, I am fine with a pm_runtime_resume() too. Maybe even simpler
in this case, as we are not using pm_runtime_force_suspend|resume()
anymore.

Kind regards
Uffe
Liming Sun Aug. 22, 2023, 7:46 p.m. UTC | #9 
> -----Original Message-----
> From: Ulf Hansson <ulf.hansson@linaro.org>
> Sent: Friday, August 18, 2023 6:19 AM
> To: Adrian Hunter <adrian.hunter@intel.com>
> Cc: Liming Sun <limings@nvidia.com>; David Thompson
> <davthompson@nvidia.com>; Shawn Lin <shawn.lin@rock-chips.com>; linux-
> mmc@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH v9] mmc: sdhci-of-dwcmshc: Add runtime PM operations
> 
> On Fri, 18 Aug 2023 at 11:36, Adrian Hunter <adrian.hunter@intel.com>
> wrote:
> >
> > On 18/08/23 12:00, Ulf Hansson wrote:
> > > On Thu, 17 Aug 2023 at 18:22, Liming Sun <limings@nvidia.com> wrote:
> > >>
> > >> This commit implements the runtime PM operations to disable eMMC
> > >> card clock when idle.
> > >>
> > >> Reviewed-by: David Thompson <davthompson@nvidia.com>
> > >> Signed-off-by: Liming Sun <limings@nvidia.com>
> > >> ---
> > >> v8->v9:
> > >>     - Address Adrian's comment to do the pm_runtime_put() in
> > >>       dwcmshc_resume() instead; Error path changes not included yet.
> > >> v7->v8:
> > >>     - Address Ulf's comment (option-1);
> > >>     - Updates for Adrian's comment to remove the force_suspend/resume
> > >>       in dwcmshc_resume()/dwcmshc_suspend(); Add comments for
> > >>       dwcmshc_resume()/dwcmshc_suspend();
> > >> v6->v7:
> > >>     - Address Ulf's comment;
> > >> v5->v6:
> > >>     - Address Adrian's more comments and add coordination between
> > >>       runtime PM and system PM;
> > >> v4->v5:
> > >>     - Address Adrian's comment to move the pm_enable to the end to
> > >>       avoid race;
> > >> v3->v4:
> > >>     - Fix compiling reported by 'kernel test robot';
> > >> v2->v3:
> > >>     - Revise the commit message;
> > >> v1->v2:
> > >>     Updates for comments from Ulf:
> > >>     - Make the runtime PM logic generic for sdhci-of-dwcmshc;
> > >> v1: Initial version.
> > >> ---
> > >>  drivers/mmc/host/sdhci-of-dwcmshc.c | 76
> +++++++++++++++++++++++++++--
> > >>  1 file changed, 72 insertions(+), 4 deletions(-)
> > >>
> > >> diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c
> b/drivers/mmc/host/sdhci-of-dwcmshc.c
> > >> index e68cd87998c8..3b40f55ce2a4 100644
> > >> --- a/drivers/mmc/host/sdhci-of-dwcmshc.c
> > >> +++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
> > >> @@ -15,6 +15,7 @@
> > >>  #include <linux/module.h>
> > >>  #include <linux/of.h>
> > >>  #include <linux/of_device.h>
> > >> +#include <linux/pm_runtime.h>
> > >>  #include <linux/reset.h>
> > >>  #include <linux/sizes.h>
> > >>
> > >> @@ -548,9 +549,13 @@ static int dwcmshc_probe(struct
> platform_device *pdev)
> > >>
> > >>         host->mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
> > >>
> > >> +       pm_runtime_get_noresume(dev);
> > >> +       pm_runtime_set_active(dev);
> > >> +       pm_runtime_enable(dev);
> > >> +
> > >>         err = sdhci_setup_host(host);
> > >>         if (err)
> > >> -               goto err_clk;
> > >> +               goto err_rpm;
> > >>
> > >>         if (rk_priv)
> > >>                 dwcmshc_rk35xx_postinit(host, priv);
> > >> @@ -559,10 +564,15 @@ static int dwcmshc_probe(struct
> platform_device *pdev)
> > >>         if (err)
> > >>                 goto err_setup_host;
> > >>
> > >> +       pm_runtime_put(dev);
> > >> +
> > >>         return 0;
> > >>
> > >>  err_setup_host:
> > >>         sdhci_cleanup_host(host);
> > >> +err_rpm:
> > >> +       pm_runtime_disable(dev);
> > >> +       pm_runtime_put_noidle(dev);
> > >>  err_clk:
> > >>         clk_disable_unprepare(pltfm_host->clk);
> > >>         clk_disable_unprepare(priv->bus_clk);
> > >> @@ -602,9 +612,13 @@ static int dwcmshc_suspend(struct device *dev)
> > >>         struct rk35xx_priv *rk_priv = priv->priv;
> > >>         int ret;
> > >>
> > >> +       pm_runtime_get_sync(dev);
> > >> +
> > >>         ret = sdhci_suspend_host(host);
> > >> -       if (ret)
> > >> +       if (ret) {
> > >> +               pm_runtime_put(dev);
> > >>                 return ret;
> > >> +       }
> > >>
> > >>         clk_disable_unprepare(pltfm_host->clk);
> > >>         if (!IS_ERR(priv->bus_clk))
> > >> @@ -642,11 +656,65 @@ static int dwcmshc_resume(struct device *dev)
> > >>                         return ret;
> > >>         }
> > >>
> > >> -       return sdhci_resume_host(host);
> > >> +       ret = sdhci_resume_host(host);
> > >> +       if (ret)
> > >> +               return ret;
> > >> +
> > >> +       pm_runtime_put(dev);
> > >
> > > To simplify the error path, I would suggest that you move the call to
> > > pm_runtime_put() to dwcmshc_suspend(). In fact what you need is just a
> > > call to pm_runtime_put_noidle(), somewhere after the call to
> > > pm_runtime_get_sync().
> > >
> > > This is because runtime suspend is prevented by the PM core as it
> > > bumps the usage count with a pm_runtime_get_noresume() in the
> > > device_prepare() phase.
> >
> > I thought you didn't want to assume that, because in that case
> > it can just be pm_runtime_resume() instead of pm_runtime_get_sync(),
> > and then no 'put' is needed at all.
> 
> I don't really care, but just wanted to keep it as simple as possible.
> 
> So yes, I am fine with a pm_runtime_resume() too. Maybe even simpler
> in this case, as we are not using pm_runtime_force_suspend|resume()
> anymore.

Thanks. Will post v10 with ' pm_runtime_resume(dev);' in dwcmshc_suspend() to keep it simple.

> 
> Kind regards
> Uffe
diff mbox series

Patch

diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
index e68cd87998c8..19ce058fc5f0 100644
--- a/drivers/mmc/host/sdhci-of-dwcmshc.c
+++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
@@ -15,6 +15,7 @@ 
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/reset.h>
 #include <linux/sizes.h>
 
@@ -542,8 +543,10 @@  static int dwcmshc_probe(struct platform_device *pdev)
 	}
 
 #ifdef CONFIG_ACPI
-	if (pltfm_data == &sdhci_dwcmshc_bf3_pdata)
+	if (pltfm_data == &sdhci_dwcmshc_bf3_pdata) {
 		sdhci_enable_v4_mode(host);
+		pm_runtime_enable(dev);
+	}
 #endif
 
 	host->mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
@@ -646,7 +649,76 @@  static int dwcmshc_resume(struct device *dev)
 }
 #endif
 
-static SIMPLE_DEV_PM_OPS(dwcmshc_pmops, dwcmshc_suspend, dwcmshc_resume);
+#ifdef CONFIG_PM
+
+#ifdef CONFIG_ACPI
+static void dwcmshc_enable_card_clk(struct sdhci_host *host)
+{
+	u16 ctrl;
+
+	ctrl = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+	ctrl |= SDHCI_CLOCK_CARD_EN;
+	sdhci_writew(host, ctrl, SDHCI_CLOCK_CONTROL);
+}
+
+static void dwcmshc_disable_card_clk(struct sdhci_host *host)
+{
+	u16 ctrl;
+
+	ctrl = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+	ctrl &= ~SDHCI_CLOCK_CARD_EN;
+	sdhci_writew(host, ctrl, SDHCI_CLOCK_CONTROL);
+}
+#endif
+
+static int dwcmshc_runtime_suspend(struct device *dev)
+{
+	struct sdhci_host *host = dev_get_drvdata(dev);
+	const struct sdhci_pltfm_data *pltfm_data;
+	int ret = 0;
+
+	pltfm_data = device_get_match_data(dev);
+	if (!pltfm_data)
+		return -ENODEV;
+
+#ifdef CONFIG_ACPI
+	if (pltfm_data == &sdhci_dwcmshc_bf3_pdata) {
+		ret = sdhci_runtime_suspend_host(host);
+		if (!ret)
+			dwcmshc_disable_card_clk(host);
+	}
+#endif
+
+	return ret;
+}
+
+static int dwcmshc_runtime_resume(struct device *dev)
+{
+	struct sdhci_host *host = dev_get_drvdata(dev);
+	const struct sdhci_pltfm_data *pltfm_data;
+	int ret = 0;
+
+	pltfm_data = device_get_match_data(dev);
+	if (!pltfm_data)
+		return -ENODEV;
+
+#ifdef CONFIG_ACPI
+	if (pltfm_data == &sdhci_dwcmshc_bf3_pdata) {
+		dwcmshc_enable_card_clk(host);
+		ret = sdhci_runtime_resume_host(host, 0);
+	}
+#endif
+
+	return ret;
+}
+
+#endif
+
+static const struct dev_pm_ops dwcmshc_pmops = {
+	SET_SYSTEM_SLEEP_PM_OPS(dwcmshc_suspend, dwcmshc_resume)
+	SET_RUNTIME_PM_OPS(dwcmshc_runtime_suspend,
+			   dwcmshc_runtime_resume, NULL)
+};
 
 static struct platform_driver sdhci_dwcmshc_driver = {
 	.driver	= {