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

[PATCH] 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. This let us know to not have any clock running and this reduce
the EMI of the device when the bus is not in use

Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
---
 drivers/mmc/host/sdhci-esdhc-imx.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index 7123ef9..9a5e96f 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -196,6 +196,7 @@ 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 */
@@ -1346,6 +1347,9 @@ static int sdhci_esdhc_runtime_suspend(struct device *dev)
 
 	ret = sdhci_runtime_suspend_host(host);
 
+	imx_data->actual_clock = host->mmc->actual_clock;
+	esdhc_pltfm_set_clock(host, 0);
+
 	if (!sdhci_sdio_irq_enabled(host)) {
 		clk_disable_unprepare(imx_data->clk_per);
 		clk_disable_unprepare(imx_data->clk_ipg);
@@ -1366,6 +1370,7 @@ static int sdhci_esdhc_runtime_resume(struct device *dev)
 		clk_prepare_enable(imx_data->clk_ipg);
 	}
 	clk_prepare_enable(imx_data->clk_ahb);
+	esdhc_pltfm_set_clock(host, imx_data->actual_clock);
 
 	return sdhci_runtime_resume_host(host);
 }
-- 
2.7.4

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

[Michael Nazzareno Trimarchi]

Hi

I have some questions:

On Thu, Dec 21, 2017 at 2:22 PM, Michael Trimarchi
<michael@amarulasolutions.com> wrote:
> mmc clock can be stopped during runtime suspend and restart during runtime
> resume. This let us know to not have any clock running and this reduce
> the EMI of the device when the bus is not in use
>
> Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
> ---
>  drivers/mmc/host/sdhci-esdhc-imx.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
> index 7123ef9..9a5e96f 100644
> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
> @@ -196,6 +196,7 @@ 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 */
> @@ -1346,6 +1347,9 @@ static int sdhci_esdhc_runtime_suspend(struct device *dev)
>
>         ret = sdhci_runtime_suspend_host(host);
>
> +       imx_data->actual_clock = host->mmc->actual_clock;
> +       esdhc_pltfm_set_clock(host, 0);
> +
>         if (!sdhci_sdio_irq_enabled(host)) {
>                 clk_disable_unprepare(imx_data->clk_per);
>                 clk_disable_unprepare(imx_data->clk_ipg);

What if the runtime suspend fail in the sdhci_runtime_suspend_host? Is
the runtime resume called?

Because in the old code the ret is not taken in account to unprepare
and disable the clock so I did not
take in account too. Is this correct?

Michael

> @@ -1366,6 +1370,7 @@ static int sdhci_esdhc_runtime_resume(struct device *dev)
>                 clk_prepare_enable(imx_data->clk_ipg);
>         }
>         clk_prepare_enable(imx_data->clk_ahb);
> +       esdhc_pltfm_set_clock(host, imx_data->actual_clock);
>
>         return sdhci_runtime_resume_host(host);
>  }
> --
> 2.7.4
>



-- 
| Michael Nazzareno Trimarchi                     Amarula Solutions BV |
| COO  -  Founder                                      Cruquiuskade 47 |
| +31(0)851119172                                 Amsterdam 1018 AM NL |
|                  [`as] http://www.amarulasolutions.com               |

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

[Ulf Hansson]

On 21 December 2017 at 14:22, Michael Trimarchi
<michael@amarulasolutions.com> wrote:
> mmc clock can be stopped during runtime suspend and restart during runtime
> resume. This let us know to not have any clock running and this reduce
> the EMI of the device when the bus is not in use
>
> Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
> ---
>  drivers/mmc/host/sdhci-esdhc-imx.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
> index 7123ef9..9a5e96f 100644
> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
> @@ -196,6 +196,7 @@ 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 */
> @@ -1346,6 +1347,9 @@ static int sdhci_esdhc_runtime_suspend(struct device *dev)
>
>         ret = sdhci_runtime_suspend_host(host);
>
> +       imx_data->actual_clock = host->mmc->actual_clock;
> +       esdhc_pltfm_set_clock(host, 0);

I guess want the clock to stay on "if sdhci_sdio_irq_enabled(host)".
So you should probably move the above inside the below if statement.

> +
>         if (!sdhci_sdio_irq_enabled(host)) {
>                 clk_disable_unprepare(imx_data->clk_per);
>                 clk_disable_unprepare(imx_data->clk_ipg);
> @@ -1366,6 +1370,7 @@ static int sdhci_esdhc_runtime_resume(struct device *dev)
>                 clk_prepare_enable(imx_data->clk_ipg);
>         }
>         clk_prepare_enable(imx_data->clk_ahb);
> +       esdhc_pltfm_set_clock(host, imx_data->actual_clock);
>
>         return sdhci_runtime_resume_host(host);
>  }
> --
> 2.7.4
>

Kind regards
Uffe

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

[Michael Nazzareno Trimarchi]

Hi

On Wed, Jan 3, 2018 at 5:26 PM, Ulf Hansson <ulf.hansson@linaro.org> wrote:
> On 21 December 2017 at 14:22, Michael Trimarchi
> <michael@amarulasolutions.com> wrote:
>> mmc clock can be stopped during runtime suspend and restart during runtime
>> resume. This let us know to not have any clock running and this reduce
>> the EMI of the device when the bus is not in use
>>
>> Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
>> ---
>>  drivers/mmc/host/sdhci-esdhc-imx.c | 5 +++++
>>  1 file changed, 5 insertions(+)
>>
>> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
>> index 7123ef9..9a5e96f 100644
>> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
>> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
>> @@ -196,6 +196,7 @@ 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 */
>> @@ -1346,6 +1347,9 @@ static int sdhci_esdhc_runtime_suspend(struct device *dev)
>>
>>         ret = sdhci_runtime_suspend_host(host);
>>
>> +       imx_data->actual_clock = host->mmc->actual_clock;
>> +       esdhc_pltfm_set_clock(host, 0);
>
> I guess want the clock to stay on "if sdhci_sdio_irq_enabled(host)".
> So you should probably move the above inside the below if statement.
>

Well I'm not quite sure about it. Some wifi chipset has the wakeup
interrupt on external gpio
and someone wakeup from DAT1. Why clock should be required?

Anyway I should even rebalance resume.

Michael

>> +
>>         if (!sdhci_sdio_irq_enabled(host)) {
>>                 clk_disable_unprepare(imx_data->clk_per);
>>                 clk_disable_unprepare(imx_data->clk_ipg);
>> @@ -1366,6 +1370,7 @@ static int sdhci_esdhc_runtime_resume(struct device *dev)
>>                 clk_prepare_enable(imx_data->clk_ipg);
>>         }
>>         clk_prepare_enable(imx_data->clk_ahb);
>> +       esdhc_pltfm_set_clock(host, imx_data->actual_clock);
>>
>>         return sdhci_runtime_resume_host(host);
>>  }
>> --
>> 2.7.4
>>
>
> Kind regards
> Uffe

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

[Ulf Hansson]

On 3 January 2018 at 17:38, Michael Nazzareno Trimarchi
<michael@amarulasolutions.com> wrote:
> Hi
>
> On Wed, Jan 3, 2018 at 5:26 PM, Ulf Hansson <ulf.hansson@linaro.org> wrote:
>> On 21 December 2017 at 14:22, Michael Trimarchi
>> <michael@amarulasolutions.com> wrote:
>>> mmc clock can be stopped during runtime suspend and restart during runtime
>>> resume. This let us know to not have any clock running and this reduce
>>> the EMI of the device when the bus is not in use
>>>
>>> Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
>>> ---
>>>  drivers/mmc/host/sdhci-esdhc-imx.c | 5 +++++
>>>  1 file changed, 5 insertions(+)
>>>
>>> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
>>> index 7123ef9..9a5e96f 100644
>>> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
>>> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
>>> @@ -196,6 +196,7 @@ 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 */
>>> @@ -1346,6 +1347,9 @@ static int sdhci_esdhc_runtime_suspend(struct device *dev)
>>>
>>>         ret = sdhci_runtime_suspend_host(host);
>>>
>>> +       imx_data->actual_clock = host->mmc->actual_clock;
>>> +       esdhc_pltfm_set_clock(host, 0);
>>
>> I guess want the clock to stay on "if sdhci_sdio_irq_enabled(host)".
>> So you should probably move the above inside the below if statement.
>>
>
> Well I'm not quite sure about it. Some wifi chipset has the wakeup
> interrupt on external gpio
> and someone wakeup from DAT1. Why clock should be required?

The clock should not be needed when using external GPIO (also
described as an out-band IRQ/wakeup), but from DAT1.

When sdhci_sdio_irq_enabled() returns true, that *should* indicate
that DAT1 is used. Although, there may be reasons to re-visit this
later, because the hole SDIO irq thing around wakeups for sdhci, is
being reworked by Adrian [1].

>
> Anyway I should even rebalance resume.

Yes.

[...]

Kind regards
Uffe

[1]
https://www.spinics.net/lists/linux-mmc/msg47512.html

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

[Michael Nazzareno Trimarchi]

Hi

On Wed, Jan 3, 2018 at 5:56 PM, Ulf Hansson <ulf.hansson@linaro.org> wrote:
> On 3 January 2018 at 17:38, Michael Nazzareno Trimarchi
> <michael@amarulasolutions.com> wrote:
>> Hi
>>
>> On Wed, Jan 3, 2018 at 5:26 PM, Ulf Hansson <ulf.hansson@linaro.org> wrote:
>>> On 21 December 2017 at 14:22, Michael Trimarchi
>>> <michael@amarulasolutions.com> wrote:
>>>> mmc clock can be stopped during runtime suspend and restart during runtime
>>>> resume. This let us know to not have any clock running and this reduce
>>>> the EMI of the device when the bus is not in use
>>>>
>>>> Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
>>>> ---
>>>>  drivers/mmc/host/sdhci-esdhc-imx.c | 5 +++++
>>>>  1 file changed, 5 insertions(+)
>>>>
>>>> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
>>>> index 7123ef9..9a5e96f 100644
>>>> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
>>>> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
>>>> @@ -196,6 +196,7 @@ 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 */
>>>> @@ -1346,6 +1347,9 @@ static int sdhci_esdhc_runtime_suspend(struct device *dev)
>>>>
>>>>         ret = sdhci_runtime_suspend_host(host);
>>>>
>>>> +       imx_data->actual_clock = host->mmc->actual_clock;
>>>> +       esdhc_pltfm_set_clock(host, 0);
>>>
>>> I guess want the clock to stay on "if sdhci_sdio_irq_enabled(host)".
>>> So you should probably move the above inside the below if statement.
>>>
>>
>> Well I'm not quite sure about it. Some wifi chipset has the wakeup
>> interrupt on external gpio
>> and someone wakeup from DAT1. Why clock should be required?
>
> The clock should not be needed when using external GPIO (also
> described as an out-band IRQ/wakeup), but from DAT1.
>

Ok, I will re-post new patches

> When sdhci_sdio_irq_enabled() returns true, that *should* indicate
> that DAT1 is used. Although, there may be reasons to re-visit this
> later, because the hole SDIO irq thing around wakeups for sdhci, is
> being reworked by Adrian [1].

I will take a look on this post

Regards

Michael

>
>>
>> Anyway I should even rebalance resume.
>
> Yes.
>
> [...]
>
> Kind regards
> Uffe
>
> [1]
> https://www.spinics.net/lists/linux-mmc/msg47512.html

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

[Michael Nazzareno Trimarchi]

Hi Ulf

I have still a small question because I'm changing this driver:

We have in sdhci_pxav3_runtime_suspend

        ret = sdhci_runtime_suspend_host(host);
        if (ret)
                return ret;

        clk_disable_unprepare(pxa->clk_io);
        if (!IS_ERR(pxa->clk_core))
                clk_disable_unprepare(pxa->clk_core);

and in the other driver like this one

        ret = sdhci_runtime_suspend_host(host);

        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);
        }
        clk_disable_unprepare(imx_data->clk_ahb);

Now to be more funny we have

int sdhci_runtime_suspend_host(struct sdhci_host *host)
{
        unsigned long flags;

        mmc_retune_timer_stop(host->mmc);
        if (host->tuning_mode != SDHCI_TUNING_MODE_3)
                mmc_retune_needed(host->mmc);

        spin_lock_irqsave(&host->lock, flags);
        host->ier &= SDHCI_INT_CARD_INT;
        sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
        sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
        spin_unlock_irqrestore(&host->lock, flags);

        synchronize_hardirq(host->irq);

        spin_lock_irqsave(&host->lock, flags);
        host->runtime_suspended = true;
        spin_unlock_irqrestore(&host->lock, flags);

        return 0;
}

Anyway. What we need to do with the clock in general if we have a fail before?

Michael

On Wed, Jan 3, 2018 at 5:58 PM, Michael Nazzareno Trimarchi
<michael@amarulasolutions.com> wrote:
> Hi
>
> On Wed, Jan 3, 2018 at 5:56 PM, Ulf Hansson <ulf.hansson@linaro.org> wrote:
>> On 3 January 2018 at 17:38, Michael Nazzareno Trimarchi
>> <michael@amarulasolutions.com> wrote:
>>> Hi
>>>
>>> On Wed, Jan 3, 2018 at 5:26 PM, Ulf Hansson <ulf.hansson@linaro.org> wrote:
>>>> On 21 December 2017 at 14:22, Michael Trimarchi
>>>> <michael@amarulasolutions.com> wrote:
>>>>> mmc clock can be stopped during runtime suspend and restart during runtime
>>>>> resume. This let us know to not have any clock running and this reduce
>>>>> the EMI of the device when the bus is not in use
>>>>>
>>>>> Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
>>>>> ---
>>>>>  drivers/mmc/host/sdhci-esdhc-imx.c | 5 +++++
>>>>>  1 file changed, 5 insertions(+)
>>>>>
>>>>> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
>>>>> index 7123ef9..9a5e96f 100644
>>>>> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
>>>>> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
>>>>> @@ -196,6 +196,7 @@ 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 */
>>>>> @@ -1346,6 +1347,9 @@ static int sdhci_esdhc_runtime_suspend(struct device *dev)
>>>>>
>>>>>         ret = sdhci_runtime_suspend_host(host);
>>>>>
>>>>> +       imx_data->actual_clock = host->mmc->actual_clock;
>>>>> +       esdhc_pltfm_set_clock(host, 0);
>>>>
>>>> I guess want the clock to stay on "if sdhci_sdio_irq_enabled(host)".
>>>> So you should probably move the above inside the below if statement.
>>>>
>>>
>>> Well I'm not quite sure about it. Some wifi chipset has the wakeup
>>> interrupt on external gpio
>>> and someone wakeup from DAT1. Why clock should be required?
>>
>> The clock should not be needed when using external GPIO (also
>> described as an out-band IRQ/wakeup), but from DAT1.
>>
>
> Ok, I will re-post new patches
>
>> When sdhci_sdio_irq_enabled() returns true, that *should* indicate
>> that DAT1 is used. Although, there may be reasons to re-visit this
>> later, because the hole SDIO irq thing around wakeups for sdhci, is
>> being reworked by Adrian [1].
>
> I will take a look on this post
>
> Regards
>
> Michael
>
>>
>>>
>>> Anyway I should even rebalance resume.
>>
>> Yes.
>>
>> [...]
>>
>> Kind regards
>> Uffe
>>
>> [1]
>> https://www.spinics.net/lists/linux-mmc/msg47512.html



-- 
| Michael Nazzareno Trimarchi                     Amarula Solutions BV |
| COO  -  Founder                                      Cruquiuskade 47 |
| +31(0)851119172                                 Amsterdam 1018 AM NL |
|                  [`as] http://www.amarulasolutions.com               |