Re: [PATCH v2 04/11] watchdog: rzg2l_wdt: Check return status of pm_runtime_put()

On 1/31/24 03:00, claudiu beznea wrote:

On 31.01.2024 12:41, Biju Das wrote:

quoted

Hi Claudiu,

quoted

-----Original Message-----
From: claudiu beznea <claudiu.beznea@tuxon.dev>
Sent: Wednesday, January 31, 2024 10:36 AM
Subject: Re: [PATCH v2 04/11] watchdog: rzg2l_wdt: Check return status of
pm_runtime_put()

Hi, Biju,

On 31.01.2024 12:32, Biju Das wrote:

quoted

Hi Claudiu,

Thanks for the feedback.

quoted

-----Original Message-----
From: Claudiu <claudiu.beznea@tuxon.dev>
Sent: Wednesday, January 31, 2024 10:20 AM
Subject: [PATCH v2 04/11] watchdog: rzg2l_wdt: Check return status of
pm_runtime_put()

From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

pm_runtime_put() may return an error code. Check its return status.

Along with it the rzg2l_wdt_set_timeout() function was updated to
propagate the result of rzg2l_wdt_stop() to its caller.

Fixes: 2cbc5cd0b55f ("watchdog: Add Watchdog Timer driver for
RZ/G2L")
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
---

Changes in v2:
- propagate the return code of rzg2l_wdt_stop() to it's callers

  drivers/watchdog/rzg2l_wdt.c | 11 +++++++++--
  1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/watchdog/rzg2l_wdt.c

b/drivers/watchdog/rzg2l_wdt.c index d87d4f50180c..7bce093316c4
100644

--- a/drivers/watchdog/rzg2l_wdt.c
+++ b/drivers/watchdog/rzg2l_wdt.c

@@ -144,9 +144,13 @@ static int rzg2l_wdt_start(struct

watchdog_device
*wdev)  static int rzg2l_wdt_stop(struct watchdog_device *wdev)  {
  	struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
+	int ret;

  	rzg2l_wdt_reset(priv);
-	pm_runtime_put(wdev->parent);
+
+	ret = pm_runtime_put(wdev->parent);
+	if (ret < 0)
+		return ret;

Do we need to check the return code? So far we didn't hit this

condition.

quoted

If you are planning to do it, then just

return pm_runtime_put(wdev->parent);

pm_runtime_put() may return 1 if the device is suspended (which is not
considered error) as explained here:

Oops, I missed that discussion. Out of curiosity,
What watchdog framework/consumer is going to do with a
Non-error return value of 1?

Looking at this:
https://elixir.bootlin.com/linux/latest/source/drivers/watchdog/watchdog_dev.c#L809

it seems that the positive values are not considered errors thus, indeed,
we may return directly:

return pm_runtime_put();

Guenter,

With this (and previous discussion from [1]), are you OK to change it like:

return pm_runtime_put();

Instead of looking at the source, I would kindly ask you to look at the API.

Guenter