diff mbox series

[1/2] watchdog: rti_wdt: Use managed APIs to handle runtime PM

Message ID 20231110100726.2930218-2-vigneshr@ti.com
State New
Headers show
Series watchdog: rti_wdt: Disable module when unused | expand

Commit Message

Vignesh Raghavendra Nov. 10, 2023, 10:07 a.m. UTC
Switch to devm_pm_runtime_enable() to simplify error handling in driver
probe.

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
---
 drivers/watchdog/rti_wdt.c | 30 ++++++++----------------------
 1 file changed, 8 insertions(+), 22 deletions(-)

Comments

Guenter Roeck Nov. 10, 2023, 3:03 p.m. UTC | #1
On 11/10/23 02:07, Vignesh Raghavendra wrote:
> Switch to devm_pm_runtime_enable() to simplify error handling in driver
> probe.
> 

This also replaces the call to pm_runtime_resume_and_get() without explanation.
Worse, the next patch conditionally re-introduces pm_runtime_put_sync()
on the probe function.

> Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
> ---
>   drivers/watchdog/rti_wdt.c | 30 ++++++++----------------------
>   1 file changed, 8 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c
> index 8e1be7ba0103..163bdeb6929a 100644
> --- a/drivers/watchdog/rti_wdt.c
> +++ b/drivers/watchdog/rti_wdt.c
> @@ -236,12 +236,8 @@ static int rti_wdt_probe(struct platform_device *pdev)
>   	if (wdt->freq < 32768)
>   		wdt->freq = wdt->freq * 9 / 10;
>   
> -	pm_runtime_enable(dev);
> -	ret = pm_runtime_resume_and_get(dev);
> -	if (ret < 0) {
> -		pm_runtime_disable(&pdev->dev);
> -		return dev_err_probe(dev, ret, "runtime pm failed\n");
> -	}
> +	devm_pm_runtime_enable(dev);

devm_pm_runtime_enable() returns an error code. I don't think ignoring it
is a good idea.

> +	pm_runtime_get_noresume(dev);

Is this functionally identical to pm_runtime_resume_and_get() ?
That would require further explanation. Why is it not necessary
to resume here ?

Also, doesn't the next patch fix or at least modify this ?

>   
>   	platform_set_drvdata(pdev, wdt);
>   
> @@ -260,7 +256,7 @@ static int rti_wdt_probe(struct platform_device *pdev)
>   	wdt->base = devm_platform_ioremap_resource(pdev, 0);
>   	if (IS_ERR(wdt->base)) {
>   		ret = PTR_ERR(wdt->base);
> -		goto err_iomap;
> +		return ret;
>   	}
>   
>   	if (readl(wdt->base + RTIDWDCTRL) == WDENABLE_KEY) {
> @@ -286,7 +282,7 @@ static int rti_wdt_probe(struct platform_device *pdev)
>   		ret = rti_wdt_setup_hw_hb(wdd, wsize);
>   		if (ret) {
>   			dev_err(dev, "bad window size.\n");
> -			goto err_iomap;
> +			return ret;
>   		}
>   
>   		last_ping = heartbeat_ms - time_left_ms;
> @@ -301,7 +297,7 @@ static int rti_wdt_probe(struct platform_device *pdev)
>   		ret = of_address_to_resource(node, 0, &res);
>   		if (ret) {
>   			dev_err(dev, "No memory address assigned to the region.\n");
> -			goto err_iomap;
> +			return ret;
>   		}
>   
>   		/*
> @@ -312,15 +308,13 @@ static int rti_wdt_probe(struct platform_device *pdev)
>   		reserved_mem_size = resource_size(&res);
>   		if (reserved_mem_size < RESERVED_MEM_MIN_SIZE) {
>   			dev_err(dev, "The size of reserved memory is too small.\n");
> -			ret = -EINVAL;
> -			goto err_iomap;
> +			return -EINVAL;
>   		}
>   
>   		vaddr = memremap(paddr, reserved_mem_size, MEMREMAP_WB);
>   		if (!vaddr) {
>   			dev_err(dev, "Failed to map memory-region.\n");
> -			ret = -ENOMEM;
> -			goto err_iomap;
> +			return -ENOMEM;
>   		}
>   
>   		if (vaddr[0] == PON_REASON_SOF_NUM &&
> @@ -337,19 +331,13 @@ static int rti_wdt_probe(struct platform_device *pdev)
>   	ret = watchdog_register_device(wdd);
>   	if (ret) {
>   		dev_err(dev, "cannot register watchdog device\n");
> -		goto err_iomap;
> +		return ret;
>   	}
>   
>   	if (last_ping)
>   		watchdog_set_last_hw_keepalive(wdd, last_ping);
>   
>   	return 0;
> -
> -err_iomap:
> -	pm_runtime_put_sync(&pdev->dev);
> -	pm_runtime_disable(&pdev->dev);
> -
> -	return ret;
>   }
>   
>   static void rti_wdt_remove(struct platform_device *pdev)
> @@ -357,8 +345,6 @@ static void rti_wdt_remove(struct platform_device *pdev)
>   	struct rti_wdt_device *wdt = platform_get_drvdata(pdev);
>   
>   	watchdog_unregister_device(&wdt->wdd);
> -	pm_runtime_put(&pdev->dev);
> -	pm_runtime_disable(&pdev->dev);
>   }
>   
>   static const struct of_device_id rti_wdt_of_match[] = {
Vignesh Raghavendra Nov. 21, 2023, 4 a.m. UTC | #2
Hi,

On 10/11/23 20:33, Guenter Roeck wrote:
> On 11/10/23 02:07, Vignesh Raghavendra wrote:
>> Switch to devm_pm_runtime_enable() to simplify error handling in driver
>> probe.
>>
> 
> This also replaces the call to pm_runtime_resume_and_get() without
> explanation.
> Worse, the next patch conditionally re-introduces pm_runtime_put_sync()
> on the probe function.
> 
>> Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
>> ---
>>   drivers/watchdog/rti_wdt.c | 30 ++++++++----------------------
>>   1 file changed, 8 insertions(+), 22 deletions(-)
>>
>> diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c
>> index 8e1be7ba0103..163bdeb6929a 100644
>> --- a/drivers/watchdog/rti_wdt.c
>> +++ b/drivers/watchdog/rti_wdt.c
>> @@ -236,12 +236,8 @@ static int rti_wdt_probe(struct platform_device
>> *pdev)
>>       if (wdt->freq < 32768)
>>           wdt->freq = wdt->freq * 9 / 10;
>>   -    pm_runtime_enable(dev);
>> -    ret = pm_runtime_resume_and_get(dev);
>> -    if (ret < 0) {
>> -        pm_runtime_disable(&pdev->dev);
>> -        return dev_err_probe(dev, ret, "runtime pm failed\n");
>> -    }
>> +    devm_pm_runtime_enable(dev);
> 
> devm_pm_runtime_enable() returns an error code. I don't think ignoring it
> is a good idea.
> 


Oops, yes...

>> +    pm_runtime_get_noresume(dev);
> 
> Is this functionally identical to pm_runtime_resume_and_get() ?
> That would require further explanation. Why is it not necessary
> to resume here ?

include/linux/pm_runtime.h ::
 pm_runtime_resume_and_get - Bump up usage counter of a device and
resume it.

vs

pm_runtime_get_noresume - Bump up runtime PM usage counter of a device.

During probe, device is already active. Hence, there is really no need
to call driver level runtime_resume() callback as there is really no
context to resume from. Driver currently doesnt have runtime_pm calls
which I intend to add as a later patch. I guess, its probably better to
move this patch to same series.

Also, missed a call to pm_runtime_put_noidle() in the error path.


So for now I will respin 2/2 as standalone fix and repost along with
runtime_pm support.

Apologies, for the delayed response!
diff mbox series

Patch

diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c
index 8e1be7ba0103..163bdeb6929a 100644
--- a/drivers/watchdog/rti_wdt.c
+++ b/drivers/watchdog/rti_wdt.c
@@ -236,12 +236,8 @@  static int rti_wdt_probe(struct platform_device *pdev)
 	if (wdt->freq < 32768)
 		wdt->freq = wdt->freq * 9 / 10;
 
-	pm_runtime_enable(dev);
-	ret = pm_runtime_resume_and_get(dev);
-	if (ret < 0) {
-		pm_runtime_disable(&pdev->dev);
-		return dev_err_probe(dev, ret, "runtime pm failed\n");
-	}
+	devm_pm_runtime_enable(dev);
+	pm_runtime_get_noresume(dev);
 
 	platform_set_drvdata(pdev, wdt);
 
@@ -260,7 +256,7 @@  static int rti_wdt_probe(struct platform_device *pdev)
 	wdt->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(wdt->base)) {
 		ret = PTR_ERR(wdt->base);
-		goto err_iomap;
+		return ret;
 	}
 
 	if (readl(wdt->base + RTIDWDCTRL) == WDENABLE_KEY) {
@@ -286,7 +282,7 @@  static int rti_wdt_probe(struct platform_device *pdev)
 		ret = rti_wdt_setup_hw_hb(wdd, wsize);
 		if (ret) {
 			dev_err(dev, "bad window size.\n");
-			goto err_iomap;
+			return ret;
 		}
 
 		last_ping = heartbeat_ms - time_left_ms;
@@ -301,7 +297,7 @@  static int rti_wdt_probe(struct platform_device *pdev)
 		ret = of_address_to_resource(node, 0, &res);
 		if (ret) {
 			dev_err(dev, "No memory address assigned to the region.\n");
-			goto err_iomap;
+			return ret;
 		}
 
 		/*
@@ -312,15 +308,13 @@  static int rti_wdt_probe(struct platform_device *pdev)
 		reserved_mem_size = resource_size(&res);
 		if (reserved_mem_size < RESERVED_MEM_MIN_SIZE) {
 			dev_err(dev, "The size of reserved memory is too small.\n");
-			ret = -EINVAL;
-			goto err_iomap;
+			return -EINVAL;
 		}
 
 		vaddr = memremap(paddr, reserved_mem_size, MEMREMAP_WB);
 		if (!vaddr) {
 			dev_err(dev, "Failed to map memory-region.\n");
-			ret = -ENOMEM;
-			goto err_iomap;
+			return -ENOMEM;
 		}
 
 		if (vaddr[0] == PON_REASON_SOF_NUM &&
@@ -337,19 +331,13 @@  static int rti_wdt_probe(struct platform_device *pdev)
 	ret = watchdog_register_device(wdd);
 	if (ret) {
 		dev_err(dev, "cannot register watchdog device\n");
-		goto err_iomap;
+		return ret;
 	}
 
 	if (last_ping)
 		watchdog_set_last_hw_keepalive(wdd, last_ping);
 
 	return 0;
-
-err_iomap:
-	pm_runtime_put_sync(&pdev->dev);
-	pm_runtime_disable(&pdev->dev);
-
-	return ret;
 }
 
 static void rti_wdt_remove(struct platform_device *pdev)
@@ -357,8 +345,6 @@  static void rti_wdt_remove(struct platform_device *pdev)
 	struct rti_wdt_device *wdt = platform_get_drvdata(pdev);
 
 	watchdog_unregister_device(&wdt->wdd);
-	pm_runtime_put(&pdev->dev);
-	pm_runtime_disable(&pdev->dev);
 }
 
 static const struct of_device_id rti_wdt_of_match[] = {