[PATCH 1/2] mmc: sdhci-esdhc-imx: Manage sdhci_runtime_suspend_host error code

[PATCH 1/2] mmc: sdhci-esdhc-imx: Manage sdhci_runtime_suspend_host error code

[Michael Trimarchi]

We need to return in case of error even if the actual implementation
of sdhci_runtime_suspend_host always return 0. We don't want to
power down the clocks and the assuption is that the sdhci_runtime_suspend_host
always let the system consistent in case of failure

Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
---
 drivers/mmc/host/sdhci-esdhc-imx.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index 85140c9..d08c21e 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -1389,6 +1389,8 @@ static int sdhci_esdhc_runtime_suspend(struct device *dev)
 	int ret;
 
 	ret = sdhci_runtime_suspend_host(host);
+	if (ret)
+		return ret;
 
 	if (host->tuning_mode != SDHCI_TUNING_MODE_3)
 		mmc_retune_needed(host->mmc);
-- 
2.7.4

[PATCH V2 2/2] mmc: sdhci-esdhc-imx: Enable/Disable mmc clock during runtime suspend

[Michael Trimarchi]

mmc clock can be stopped during runtime suspend and restart during runtime
resume if the sdio irq is not enabled. Stop sdio clock reduce EMI of
the device when the bus is not in use.

Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
---
Changes V1->V2:
	- rebase to latest linux
	- address sdio irq wakeup
	- move the clock enable clk_ahb up to be balance
	  with the runtime suspend function and to make
	  function more clean by the end without two if
	  condition
---
 drivers/mmc/host/sdhci-esdhc-imx.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index d08c21e..53cc1b6 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -193,6 +193,7 @@ struct pltfm_imx_data {
 	struct clk *clk_ipg;
 	struct clk *clk_ahb;
 	struct clk *clk_per;
+	unsigned int actual_clock;
 	enum {
 		NO_CMD_PENDING,      /* no multiblock command pending */
 		MULTIBLK_IN_PROCESS, /* exact multiblock cmd in process */
@@ -1396,6 +1397,8 @@ static int sdhci_esdhc_runtime_suspend(struct device *dev)
 		mmc_retune_needed(host->mmc);
 
 	if (!sdhci_sdio_irq_enabled(host)) {
+		imx_data->actual_clock = host->mmc->actual_clock;
+		esdhc_pltfm_set_clock(host, 0);
 		clk_disable_unprepare(imx_data->clk_per);
 		clk_disable_unprepare(imx_data->clk_ipg);
 	}
@@ -1411,31 +1414,34 @@ static int sdhci_esdhc_runtime_resume(struct device *dev)
 	struct pltfm_imx_data *imx_data = sdhci_pltfm_priv(pltfm_host);
 	int err;
 
+	err = clk_prepare_enable(imx_data->clk_ahb);
+	if (err)
+		return err;
+
 	if (!sdhci_sdio_irq_enabled(host)) {
 		err = clk_prepare_enable(imx_data->clk_per);
 		if (err)
-			return err;
+			goto disable_ahb_clk;
 		err = clk_prepare_enable(imx_data->clk_ipg);
 		if (err)
 			goto disable_per_clk;
+		esdhc_pltfm_set_clock(host, imx_data->actual_clock);
 	}
-	err = clk_prepare_enable(imx_data->clk_ahb);
-	if (err)
-		goto disable_ipg_clk;
+
 	err = sdhci_runtime_resume_host(host);
 	if (err)
-		goto disable_ahb_clk;
+		goto disable_ipg_clk;
 
 	return 0;
 
-disable_ahb_clk:
-	clk_disable_unprepare(imx_data->clk_ahb);
 disable_ipg_clk:
 	if (!sdhci_sdio_irq_enabled(host))
 		clk_disable_unprepare(imx_data->clk_ipg);
 disable_per_clk:
 	if (!sdhci_sdio_irq_enabled(host))
 		clk_disable_unprepare(imx_data->clk_per);
+disable_ahb_clk:
+	clk_disable_unprepare(imx_data->clk_ahb);
 	return err;
 }
 #endif
-- 
2.7.4

Re: [PATCH V2 2/2] mmc: sdhci-esdhc-imx: Enable/Disable mmc clock during runtime suspend

[Ulf Hansson]

On 4 January 2018 at 14:58, Michael Trimarchi
<michael@amarulasolutions.com> wrote:
> mmc clock can be stopped during runtime suspend and restart during runtime
> resume if the sdio irq is not enabled. Stop sdio clock reduce EMI of
> the device when the bus is not in use.
>
> Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
> ---
> Changes V1->V2:
>         - rebase to latest linux
>         - address sdio irq wakeup
>         - move the clock enable clk_ahb up to be balance
>           with the runtime suspend function and to make
>           function more clean by the end without two if
>           condition
> ---
>  drivers/mmc/host/sdhci-esdhc-imx.c | 20 +++++++++++++-------
>  1 file changed, 13 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
> index d08c21e..53cc1b6 100644
> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
> @@ -193,6 +193,7 @@ struct pltfm_imx_data {
>         struct clk *clk_ipg;
>         struct clk *clk_ahb;
>         struct clk *clk_per;
> +       unsigned int actual_clock;
>         enum {
>                 NO_CMD_PENDING,      /* no multiblock command pending */
>                 MULTIBLK_IN_PROCESS, /* exact multiblock cmd in process */
> @@ -1396,6 +1397,8 @@ static int sdhci_esdhc_runtime_suspend(struct device *dev)
>                 mmc_retune_needed(host->mmc);
>
>         if (!sdhci_sdio_irq_enabled(host)) {
> +               imx_data->actual_clock = host->mmc->actual_clock;
> +               esdhc_pltfm_set_clock(host, 0);
>                 clk_disable_unprepare(imx_data->clk_per);
>                 clk_disable_unprepare(imx_data->clk_ipg);
>         }
> @@ -1411,31 +1414,34 @@ static int sdhci_esdhc_runtime_resume(struct device *dev)
>         struct pltfm_imx_data *imx_data = sdhci_pltfm_priv(pltfm_host);
>         int err;
>
> +       err = clk_prepare_enable(imx_data->clk_ahb);
> +       if (err)
> +               return err;
> +

So this changes the order of how clocks are being re-enabled. I think
the change makes sense, as normally we do things in the reverse order
as compared what is being done during ->runtime_suspend().

However, I think you should have this being a separate patch,
preceding the one that actually calls esdhc_pltfm_set_clock() in in
the runtime PM callbacks.

>         if (!sdhci_sdio_irq_enabled(host)) {
>                 err = clk_prepare_enable(imx_data->clk_per);
>                 if (err)
> -                       return err;
> +                       goto disable_ahb_clk;
>                 err = clk_prepare_enable(imx_data->clk_ipg);
>                 if (err)
>                         goto disable_per_clk;
> +               esdhc_pltfm_set_clock(host, imx_data->actual_clock);
>         }
> -       err = clk_prepare_enable(imx_data->clk_ahb);
> -       if (err)
> -               goto disable_ipg_clk;
> +
>         err = sdhci_runtime_resume_host(host);
>         if (err)
> -               goto disable_ahb_clk;
> +               goto disable_ipg_clk;
>
>         return 0;
>
> -disable_ahb_clk:
> -       clk_disable_unprepare(imx_data->clk_ahb);
>  disable_ipg_clk:
>         if (!sdhci_sdio_irq_enabled(host))
>                 clk_disable_unprepare(imx_data->clk_ipg);
>  disable_per_clk:
>         if (!sdhci_sdio_irq_enabled(host))
>                 clk_disable_unprepare(imx_data->clk_per);
> +disable_ahb_clk:
> +       clk_disable_unprepare(imx_data->clk_ahb);
>         return err;
>  }
>  #endif
> --
> 2.7.4
>

Otherwise this looks good to me.

Kind regards
Uffe