[PATCH 1/4] rtc: s3c: add missing clk control

[PATCH 1/4] rtc: s3c: add missing clk control

[Joonyoung Shim]

It's missed to call clk_unprepare() about info->rtc_src_clk in
s3c_rtc_remove and to call clk_disable_unprepare about info->rtc_clk in
error routine of s3c_rtc_probe.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
---
 drivers/rtc/rtc-s3c.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c
index a0f8323..d1866a4 100644
--- a/drivers/rtc/rtc-s3c.c
+++ b/drivers/rtc/rtc-s3c.c
@@ -410,6 +410,8 @@ static int s3c_rtc_remove(struct platform_device *pdev)
 
 	s3c_rtc_setaie(info->dev, 0);
 
+	if (info->data->needs_src_clk)
+		clk_unprepare(info->rtc_src_clk);
 	clk_unprepare(info->rtc_clk);
 	info->rtc_clk = NULL;
 
@@ -482,6 +484,7 @@ static int s3c_rtc_probe(struct platform_device *pdev)
 		if (IS_ERR(info->rtc_src_clk)) {
 			dev_err(&pdev->dev,
 				"failed to find rtc source clock\n");
+			clk_disable_unprepare(info->rtc_clk);
 			return PTR_ERR(info->rtc_src_clk);
 		}
 		clk_prepare_enable(info->rtc_src_clk);
-- 
1.9.1

[PATCH 2/4] rtc: s3c: remove unnecessary NULL assignment

[Joonyoung Shim]

It's unnecessary the code that assigns info->rtc_clk to NULL in
s3c_rtc_remove.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
---
 drivers/rtc/rtc-s3c.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c
index d1866a4..44b2921 100644
--- a/drivers/rtc/rtc-s3c.c
+++ b/drivers/rtc/rtc-s3c.c
@@ -413,7 +413,6 @@ static int s3c_rtc_remove(struct platform_device *pdev)
 	if (info->data->needs_src_clk)
 		clk_unprepare(info->rtc_src_clk);
 	clk_unprepare(info->rtc_clk);
-	info->rtc_clk = NULL;
 
 	return 0;
 }
-- 
1.9.1

Re: [PATCH 2/4] rtc: s3c: remove unnecessary NULL assignment

[Krzysztof Kozlowski]

On 11.08.2015 20:28, Joonyoung Shim wrote:
> It's unnecessary the code that assigns info->rtc_clk to NULL in
> s3c_rtc_remove.
> 
> Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
> ---
>  drivers/rtc/rtc-s3c.c | 1 -
>  1 file changed, 1 deletion(-)

Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

Best regards,
Krzysztof

Re: [PATCH 2/4] rtc: s3c: remove unnecessary NULL assignment

[Alexandre Belloni]

On 11/08/2015 at 20:28:20 +0900, Joonyoung Shim wrote :
> It's unnecessary the code that assigns info->rtc_clk to NULL in
> s3c_rtc_remove.
> 
> Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
> ---
>  drivers/rtc/rtc-s3c.c | 1 -
>  1 file changed, 1 deletion(-)
> 
Applied, thanks.

-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

[PATCH 3/4] rtc: s3c: use unified functions for enable/disable of clk

[Joonyoung Shim]

The driver uses clk_prepare_enable()/clk_disable_unprepare() only in
probe only, elsewhere, use the unified functions for enable/disable of
clk, e.g. s3c_rtc_enable_clk() / s3c_rtc_disable_clk(), so it's better
to use them for consistency of code.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
---
 drivers/rtc/rtc-s3c.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c
index 44b2921..abe2a6d 100644
--- a/drivers/rtc/rtc-s3c.c
+++ b/drivers/rtc/rtc-s3c.c
@@ -476,19 +476,21 @@ static int s3c_rtc_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "failed to find rtc clock\n");
 		return PTR_ERR(info->rtc_clk);
 	}
-	clk_prepare_enable(info->rtc_clk);
+	clk_prepare(info->rtc_clk);
 
 	if (info->data->needs_src_clk) {
 		info->rtc_src_clk = devm_clk_get(&pdev->dev, "rtc_src");
 		if (IS_ERR(info->rtc_src_clk)) {
 			dev_err(&pdev->dev,
 				"failed to find rtc source clock\n");
-			clk_disable_unprepare(info->rtc_clk);
+			clk_unprepare(info->rtc_clk);
 			return PTR_ERR(info->rtc_src_clk);
 		}
-		clk_prepare_enable(info->rtc_src_clk);
+		clk_prepare(info->rtc_src_clk);
 	}
 
+	s3c_rtc_enable_clk(info);
+
 	/* check to see if everything is setup correctly */
 	if (info->data->enable)
 		info->data->enable(info);
@@ -548,9 +550,11 @@ static int s3c_rtc_probe(struct platform_device *pdev)
 	if (info->data->disable)
 		info->data->disable(info);
 
+	s3c_rtc_disable_clk(info);
+
 	if (info->data->needs_src_clk)
-		clk_disable_unprepare(info->rtc_src_clk);
-	clk_disable_unprepare(info->rtc_clk);
+		clk_unprepare(info->rtc_src_clk);
+	clk_unprepare(info->rtc_clk);
 
 	return ret;
 }
-- 
1.9.1

Re: [PATCH 3/4] rtc: s3c: use unified functions for enable/disable of clk

[Krzysztof Kozlowski]

On 11.08.2015 20:28, Joonyoung Shim wrote:
> The driver uses clk_prepare_enable()/clk_disable_unprepare() only in
> probe only, elsewhere, use the unified functions for enable/disable of
> clk, e.g. s3c_rtc_enable_clk() / s3c_rtc_disable_clk(), so it's better
> to use them for consistency of code.
> 
> Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
> ---
>  drivers/rtc/rtc-s3c.c | 14 +++++++++-----
>  1 file changed, 9 insertions(+), 5 deletions(-)

First of all - the code is larger (9 insertions, 5 deletion) so I have
doubts if this is better.

Second - this is not equivalent change. The s3c_rtc_enable_clk/disable
calls grab spin lock which is not necessary in probe.

Best regards,
Krzysztof

> 
> diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c
> index 44b2921..abe2a6d 100644
> --- a/drivers/rtc/rtc-s3c.c
> +++ b/drivers/rtc/rtc-s3c.c
> @@ -476,19 +476,21 @@ static int s3c_rtc_probe(struct platform_device *pdev)
>  		dev_err(&pdev->dev, "failed to find rtc clock\n");
>  		return PTR_ERR(info->rtc_clk);
>  	}
> -	clk_prepare_enable(info->rtc_clk);
> +	clk_prepare(info->rtc_clk);
>  
>  	if (info->data->needs_src_clk) {
>  		info->rtc_src_clk = devm_clk_get(&pdev->dev, "rtc_src");
>  		if (IS_ERR(info->rtc_src_clk)) {
>  			dev_err(&pdev->dev,
>  				"failed to find rtc source clock\n");
> -			clk_disable_unprepare(info->rtc_clk);
> +			clk_unprepare(info->rtc_clk);
>  			return PTR_ERR(info->rtc_src_clk);
>  		}
> -		clk_prepare_enable(info->rtc_src_clk);
> +		clk_prepare(info->rtc_src_clk);
>  	}
>  
> +	s3c_rtc_enable_clk(info);
> +
>  	/* check to see if everything is setup correctly */
>  	if (info->data->enable)
>  		info->data->enable(info);
> @@ -548,9 +550,11 @@ static int s3c_rtc_probe(struct platform_device *pdev)
>  	if (info->data->disable)
>  		info->data->disable(info);
>  
> +	s3c_rtc_disable_clk(info);
> +
>  	if (info->data->needs_src_clk)
> -		clk_disable_unprepare(info->rtc_src_clk);
> -	clk_disable_unprepare(info->rtc_clk);
> +		clk_unprepare(info->rtc_src_clk);
> +	clk_unprepare(info->rtc_clk);
>  
>  	return ret;
>  }
> 

Re: [PATCH 3/4] rtc: s3c: use unified functions for enable/disable of clk

[Joonyoung Shim]

On 08/12/2015 09:10 AM, Krzysztof Kozlowski wrote:
> On 11.08.2015 20:28, Joonyoung Shim wrote:
>> The driver uses clk_prepare_enable()/clk_disable_unprepare() only in
>> probe only, elsewhere, use the unified functions for enable/disable of
>> clk, e.g. s3c_rtc_enable_clk() / s3c_rtc_disable_clk(), so it's better
>> to use them for consistency of code.
>>
>> Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
>> ---
>>  drivers/rtc/rtc-s3c.c | 14 +++++++++-----
>>  1 file changed, 9 insertions(+), 5 deletions(-)
> 
> First of all - the code is larger (9 insertions, 5 deletion) so I have
> doubts if this is better.
> 
> Second - this is not equivalent change. The s3c_rtc_enable_clk/disable
> calls grab spin lock which is not necessary in probe.
> 

I made this patch because of patch 4/4, but patch 4/4 should be removed
dependency from previous patches, so i will drop this patch.

Thanks.

[PATCH 4/4] rtc: s3c: enable/disable clocks for alarm

[Joonyoung Shim]

The clock enable/disable codes for alarm have removed from
'commit 24e1455493da ("drivers/rtc/rtc-s3c.c: delete duplicate clock
control")' and the clocks keep disabling even if alarm is set, so alarm
interrupt can't happen.

The s3c_rtc_setaie function can be called several times with that
enabled argument has same value, so it needs to check whether clocks is
enabled or not.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
---
 drivers/rtc/rtc-s3c.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c
index abe2a6d..fce078c 100644
--- a/drivers/rtc/rtc-s3c.c
+++ b/drivers/rtc/rtc-s3c.c
@@ -39,6 +39,7 @@ struct s3c_rtc {
 	void __iomem *base;
 	struct clk *rtc_clk;
 	struct clk *rtc_src_clk;
+	bool clk_enabled;
 
 	struct s3c_rtc_data *data;
 
@@ -71,9 +72,12 @@ static void s3c_rtc_enable_clk(struct s3c_rtc *info)
 	unsigned long irq_flags;
 
 	spin_lock_irqsave(&info->alarm_clk_lock, irq_flags);
-	clk_enable(info->rtc_clk);
-	if (info->data->needs_src_clk)
-		clk_enable(info->rtc_src_clk);
+	if (!info->clk_enabled) {
+		clk_enable(info->rtc_clk);
+		if (info->data->needs_src_clk)
+			clk_enable(info->rtc_src_clk);
+		info->clk_enabled = true;
+	}
 	spin_unlock_irqrestore(&info->alarm_clk_lock, irq_flags);
 }
 
@@ -82,9 +86,12 @@ static void s3c_rtc_disable_clk(struct s3c_rtc *info)
 	unsigned long irq_flags;
 
 	spin_lock_irqsave(&info->alarm_clk_lock, irq_flags);
-	if (info->data->needs_src_clk)
-		clk_disable(info->rtc_src_clk);
-	clk_disable(info->rtc_clk);
+	if (info->clk_enabled) {
+		if (info->data->needs_src_clk)
+			clk_disable(info->rtc_src_clk);
+		clk_disable(info->rtc_clk);
+		info->clk_enabled = false;
+	}
 	spin_unlock_irqrestore(&info->alarm_clk_lock, irq_flags);
 }
 
@@ -128,6 +135,11 @@ static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
 
 	s3c_rtc_disable_clk(info);
 
+	if (enabled)
+		s3c_rtc_enable_clk(info);
+	else
+		s3c_rtc_disable_clk(info);
+
 	return 0;
 }
 
-- 
1.9.1

Re: [PATCH 4/4] rtc: s3c: enable/disable clocks for alarm

[Krzysztof Kozlowski]

On 11.08.2015 20:28, Joonyoung Shim wrote:
> The clock enable/disable codes for alarm have removed from

What do you mean in this paragraph? The clock code was removing something?

> 'commit 24e1455493da ("drivers/rtc/rtc-s3c.c: delete duplicate clock

Remove the 'apostrophe.

> control")' and the clocks keep disabling even if alarm is set, so alarm
> interrupt can't happen.
...and the clocks are disabled even...


> 
> The s3c_rtc_setaie function can be called several times with that
> enabled argument has same value,
...several times with 'enabled' argument having same value

> so it needs to check whether clocks is
> enabled or not.
s/is/are/

> 
> Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>

Please add Cc-stable and fixes tag. To backport the patch probably
you'll have to remove the dependency on previous patches.

> ---
>  drivers/rtc/rtc-s3c.c | 24 ++++++++++++++++++------
>  1 file changed, 18 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c
> index abe2a6d..fce078c 100644
> --- a/drivers/rtc/rtc-s3c.c
> +++ b/drivers/rtc/rtc-s3c.c
> @@ -39,6 +39,7 @@ struct s3c_rtc {
>  	void __iomem *base;
>  	struct clk *rtc_clk;
>  	struct clk *rtc_src_clk;
> +	bool clk_enabled;
>  
>  	struct s3c_rtc_data *data;
>  
> @@ -71,9 +72,12 @@ static void s3c_rtc_enable_clk(struct s3c_rtc *info)
>  	unsigned long irq_flags;
>  
>  	spin_lock_irqsave(&info->alarm_clk_lock, irq_flags);
> -	clk_enable(info->rtc_clk);
> -	if (info->data->needs_src_clk)
> -		clk_enable(info->rtc_src_clk);
> +	if (!info->clk_enabled) {
> +		clk_enable(info->rtc_clk);
> +		if (info->data->needs_src_clk)
> +			clk_enable(info->rtc_src_clk);
> +		info->clk_enabled = true;
> +	}
>  	spin_unlock_irqrestore(&info->alarm_clk_lock, irq_flags);
>  }
>  
> @@ -82,9 +86,12 @@ static void s3c_rtc_disable_clk(struct s3c_rtc *info)
>  	unsigned long irq_flags;
>  
>  	spin_lock_irqsave(&info->alarm_clk_lock, irq_flags);
> -	if (info->data->needs_src_clk)
> -		clk_disable(info->rtc_src_clk);
> -	clk_disable(info->rtc_clk);
> +	if (info->clk_enabled) {
> +		if (info->data->needs_src_clk)
> +			clk_disable(info->rtc_src_clk);
> +		clk_disable(info->rtc_clk);
> +		info->clk_enabled = false;
> +	}
>  	spin_unlock_irqrestore(&info->alarm_clk_lock, irq_flags);
>  }
>  
> @@ -128,6 +135,11 @@ static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)
>  
>  	s3c_rtc_disable_clk(info);
>  
> +	if (enabled)
> +		s3c_rtc_enable_clk(info);
> +	else
> +		s3c_rtc_disable_clk(info);
> +
>  	return 0;
>  }

During probe the clk_enabled is false, so the clock won't be disabled at
the end of probe with s3c_rtc_disable_clk(). Maybe previous patch
interferes here so it would work after applying all 4 patches but not
when backporting. The patch in current form looks non-backportable.

Best regards,
KRzysztof

Re: [PATCH 4/4] rtc: s3c: enable/disable clocks for alarm

[Joonyoung Shim]

On 08/12/2015 09:28 AM, Krzysztof Kozlowski wrote:
> On 11.08.2015 20:28, Joonyoung Shim wrote:
>> The clock enable/disable codes for alarm have removed from
> 
> What do you mean in this paragraph? The clock code was removing something?
> 
>> 'commit 24e1455493da ("drivers/rtc/rtc-s3c.c: delete duplicate clock
> 
> Remove the 'apostrophe.
> 
>> control")' and the clocks keep disabling even if alarm is set, so alarm
>> interrupt can't happen.
> ...and the clocks are disabled even...
> 
> 
>>
>> The s3c_rtc_setaie function can be called several times with that
>> enabled argument has same value,
> ...several times with 'enabled' argument having same value
> 
>> so it needs to check whether clocks is
>> enabled or not.
> s/is/are/
> 
>>
>> Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
> 
> Please add Cc-stable and fixes tag. To backport the patch probably
> you'll have to remove the dependency on previous patches.

Thanks for the point, i didn't think it.

Re: [PATCH 1/4] rtc: s3c: add missing clk control

[Krzysztof Kozlowski]

On 11.08.2015 20:28, Joonyoung Shim wrote:
> It's missed to call clk_unprepare() about info->rtc_src_clk in
> s3c_rtc_remove and to call clk_disable_unprepare about info->rtc_clk in
> error routine of s3c_rtc_probe.
> 
> Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
> ---
>  drivers/rtc/rtc-s3c.c | 3 +++
>  1 file changed, 3 insertions(+)

Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

Best regards,
Krzysztof

Re: [PATCH 1/4] rtc: s3c: add missing clk control

[Alexandre Belloni]

On 11/08/2015 at 20:28:19 +0900, Joonyoung Shim wrote :
> It's missed to call clk_unprepare() about info->rtc_src_clk in
> s3c_rtc_remove and to call clk_disable_unprepare about info->rtc_clk in
> error routine of s3c_rtc_probe.
> 
> Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
> ---
>  drivers/rtc/rtc-s3c.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
Applied, thanks.

-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com