2024-04-10 14:17:56

by Biju Das

[permalink] [raw]
Subject: RE: [PATCH RESEND v8 03/10] watchdog: rzg2l_wdt: Use pm_runtime_resume_and_get()

Hi Claudiu,

> -----Original Message-----
> From: Claudiu <[email protected]>
> Sent: Wednesday, April 10, 2024 2:41 PM
> Subject: [PATCH RESEND v8 03/10] watchdog: rzg2l_wdt: Use pm_runtime_resume_and_get()
>
> From: Claudiu Beznea <[email protected]>
>
> pm_runtime_get_sync() may return with error. In case it returns with error
> dev->power.usage_count needs to be decremented.
> dev->pm_runtime_resume_and_get()
> takes care of this. Thus use it.
>
> Along with it the rzg2l_wdt_set_timeout() function was updated to propagate the result of
> rzg2l_wdt_start() to its caller.
>
> Fixes: 2cbc5cd0b55f ("watchdog: Add Watchdog Timer driver for RZ/G2L")
> Signed-off-by: Claudiu Beznea <[email protected]>
> ---
>
> Changes in v8:
> - none
>
> Changes in v7:
> - none
>
> Changes in v6:
> - none
>
> Changes in v5:
> - none
>
> Changes in v4:
> - none
>
> Changes in v3:
> - none
>
> Changes in v2:
> - propagate the return code of rzg2l_wdt_start() to it's callers
>
>
> drivers/watchdog/rzg2l_wdt.c | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c index
> 1741f98ca67c..d87d4f50180c 100644
> --- a/drivers/watchdog/rzg2l_wdt.c
> +++ b/drivers/watchdog/rzg2l_wdt.c
> @@ -123,8 +123,11 @@ static void rzg2l_wdt_init_timeout(struct watchdog_device *wdev) static int
> rzg2l_wdt_start(struct watchdog_device *wdev) {
> struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
> + int ret;
>
> - pm_runtime_get_sync(wdev->parent);
> + ret = pm_runtime_resume_and_get(wdev->parent);

Do we need this change at all? If we have balanced usage then
this won't be a issue. Did any unbalanced usage count popup
during the testing?

Cheers,
Biju

> + if (ret)
> + return ret;
>
> /* Initialize time out */
> rzg2l_wdt_init_timeout(wdev);
> @@ -150,6 +153,8 @@ static int rzg2l_wdt_stop(struct watchdog_device *wdev)
>
> static int rzg2l_wdt_set_timeout(struct watchdog_device *wdev, unsigned int timeout) {
> + int ret = 0;
> +
> wdev->timeout = timeout;
>
> /*
> @@ -159,10 +164,10 @@ static int rzg2l_wdt_set_timeout(struct watchdog_device *wdev, unsigned int
> time
> */
> if (watchdog_active(wdev)) {
> rzg2l_wdt_stop(wdev);
> - rzg2l_wdt_start(wdev);
> + ret = rzg2l_wdt_start(wdev);
> }
>
> - return 0;
> + return ret;
> }
>
> static int rzg2l_wdt_restart(struct watchdog_device *wdev,
> --
> 2.39.2



2024-04-11 11:12:57

by Claudiu

[permalink] [raw]
Subject: Re: [PATCH RESEND v8 03/10] watchdog: rzg2l_wdt: Use pm_runtime_resume_and_get()



On 10.04.2024 17:13, Biju Das wrote:
> Hi Claudiu,
>
>> -----Original Message-----
>> From: Claudiu <[email protected]>
>> Sent: Wednesday, April 10, 2024 2:41 PM
>> Subject: [PATCH RESEND v8 03/10] watchdog: rzg2l_wdt: Use pm_runtime_resume_and_get()
>>
>> From: Claudiu Beznea <[email protected]>
>>
>> pm_runtime_get_sync() may return with error. In case it returns with error
>> dev->power.usage_count needs to be decremented.
>> dev->pm_runtime_resume_and_get()
>> takes care of this. Thus use it.
>>
>> Along with it the rzg2l_wdt_set_timeout() function was updated to propagate the result of
>> rzg2l_wdt_start() to its caller.
>>
>> Fixes: 2cbc5cd0b55f ("watchdog: Add Watchdog Timer driver for RZ/G2L")
>> Signed-off-by: Claudiu Beznea <[email protected]>
>> ---
>>
>> Changes in v8:
>> - none
>>
>> Changes in v7:
>> - none
>>
>> Changes in v6:
>> - none
>>
>> Changes in v5:
>> - none
>>
>> Changes in v4:
>> - none
>>
>> Changes in v3:
>> - none
>>
>> Changes in v2:
>> - propagate the return code of rzg2l_wdt_start() to it's callers
>>
>>
>> drivers/watchdog/rzg2l_wdt.c | 11 ++++++++---
>> 1 file changed, 8 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c index
>> 1741f98ca67c..d87d4f50180c 100644
>> --- a/drivers/watchdog/rzg2l_wdt.c
>> +++ b/drivers/watchdog/rzg2l_wdt.c
>> @@ -123,8 +123,11 @@ static void rzg2l_wdt_init_timeout(struct watchdog_device *wdev) static int
>> rzg2l_wdt_start(struct watchdog_device *wdev) {
>> struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
>> + int ret;
>>
>> - pm_runtime_get_sync(wdev->parent);
>> + ret = pm_runtime_resume_and_get(wdev->parent);
>
> Do we need this change at all?

I haven't encountered issues w/o this patch, though I've did all my testing
(including suspend to RAM) with this patch on my tree.

> If we have balanced usage then
> this won't be a issue.

I think we should just use the proper APIs w/o making assumptions.

> Did any unbalanced usage count popup
> during the testing?
>
> Cheers,
> Biju
>
>> + if (ret)
>> + return ret;
>>
>> /* Initialize time out */
>> rzg2l_wdt_init_timeout(wdev);
>> @@ -150,6 +153,8 @@ static int rzg2l_wdt_stop(struct watchdog_device *wdev)
>>
>> static int rzg2l_wdt_set_timeout(struct watchdog_device *wdev, unsigned int timeout) {
>> + int ret = 0;
>> +
>> wdev->timeout = timeout;
>>
>> /*
>> @@ -159,10 +164,10 @@ static int rzg2l_wdt_set_timeout(struct watchdog_device *wdev, unsigned int
>> time
>> */
>> if (watchdog_active(wdev)) {
>> rzg2l_wdt_stop(wdev);
>> - rzg2l_wdt_start(wdev);
>> + ret = rzg2l_wdt_start(wdev);
>> }
>>
>> - return 0;
>> + return ret;
>> }
>>
>> static int rzg2l_wdt_restart(struct watchdog_device *wdev,
>> --
>> 2.39.2
>