[4/5] watchdog: ziirave_wdt: Don't bail out on unexpected timeout value
diff mbox series

Message ID 20190731174252.18041-5-andrew.smirnov@gmail.com
State Accepted
Headers show
Series
  • Ziirave_wdt driver fixes
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Commit Message

Andrey Smirnov July 31, 2019, 5:42 p.m. UTC
Reprogramming bootloader on watchdog MCU will result in reported
default timeout value of "0". That in turn will be unnecesarily
rejected by the driver as invalid device (-ENODEV). Simplify probe to
just read stored timeout value, clamp it to an acceptable range and
program the value unconditionally to fix the above.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: Chris Healy <cphealy@gmail.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Rick Ramstetter <rick@anteaterllc.com>
Cc: linux-watchdog@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 drivers/watchdog/ziirave_wdt.c | 22 +++++++++-------------
 1 file changed, 9 insertions(+), 13 deletions(-)

Comments

Guenter Roeck July 31, 2019, 6:09 p.m. UTC | #1
On Wed, Jul 31, 2019 at 10:42:51AM -0700, Andrey Smirnov wrote:
> Reprogramming bootloader on watchdog MCU will result in reported
> default timeout value of "0". That in turn will be unnecesarily

unnecessarily

> rejected by the driver as invalid device (-ENODEV). Simplify probe to
> just read stored timeout value, clamp it to an acceptable range and
> program the value unconditionally to fix the above.
> 
> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
> Cc: Chris Healy <cphealy@gmail.com>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: Rick Ramstetter <rick@anteaterllc.com>
> Cc: linux-watchdog@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> ---
>  drivers/watchdog/ziirave_wdt.c | 22 +++++++++-------------
>  1 file changed, 9 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/watchdog/ziirave_wdt.c b/drivers/watchdog/ziirave_wdt.c
> index 89ce6982ba53..33c8d2eadada 100644
> --- a/drivers/watchdog/ziirave_wdt.c
> +++ b/drivers/watchdog/ziirave_wdt.c
> @@ -667,22 +667,18 @@ static int ziirave_wdt_probe(struct i2c_client *client,
>  			return val;
>  		}
>  
> -		if (val < ZIIRAVE_TIMEOUT_MIN)
> -			return -ENODEV;
> -
> -		w_priv->wdd.timeout = val;
> -	} else {
> -		ret = ziirave_wdt_set_timeout(&w_priv->wdd,
> -					      w_priv->wdd.timeout);
> -		if (ret) {
> -			dev_err(&client->dev, "Failed to set timeout\n");
> -			return ret;
> -		}
> +		w_priv->wdd.timeout = clamp(val, ZIIRAVE_TIMEOUT_MIN,
> +					    ZIIRAVE_TIMEOUT_MAX);

Are you sure ? Effectively that will set the timeout to the minimum,
ie three seconds. It might be better to define and set some default.
Your call, of course.

Thanks,
Guenter

> +	}
>  
> -		dev_info(&client->dev, "Timeout set to %ds\n",
> -			 w_priv->wdd.timeout);
> +	ret = ziirave_wdt_set_timeout(&w_priv->wdd, w_priv->wdd.timeout);
> +	if (ret) {
> +		dev_err(&client->dev, "Failed to set timeout\n");
> +		return ret;
>  	}
>  
> +	dev_info(&client->dev, "Timeout set to %ds\n", w_priv->wdd.timeout);
> +
>  	watchdog_set_nowayout(&w_priv->wdd, nowayout);
>  
>  	i2c_set_clientdata(client, w_priv);
> -- 
> 2.21.0
>
Guenter Roeck Aug. 2, 2019, 8:49 p.m. UTC | #2
On Wed, Jul 31, 2019 at 10:42:51AM -0700, Andrey Smirnov wrote:
> Reprogramming bootloader on watchdog MCU will result in reported
> default timeout value of "0". That in turn will be unnecesarily
> rejected by the driver as invalid device (-ENODEV). Simplify probe to
> just read stored timeout value, clamp it to an acceptable range and
> program the value unconditionally to fix the above.
> 
> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
> Cc: Chris Healy <cphealy@gmail.com>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: Rick Ramstetter <rick@anteaterllc.com>
> Cc: linux-watchdog@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org

I have not heard back on the question I had about selecting the minimum
timeout and not a more reasonable default. Since the code itself
is technically correct, marking the patch as

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

Guenter

> ---
>  drivers/watchdog/ziirave_wdt.c | 22 +++++++++-------------
>  1 file changed, 9 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/watchdog/ziirave_wdt.c b/drivers/watchdog/ziirave_wdt.c
> index 89ce6982ba53..33c8d2eadada 100644
> --- a/drivers/watchdog/ziirave_wdt.c
> +++ b/drivers/watchdog/ziirave_wdt.c
> @@ -667,22 +667,18 @@ static int ziirave_wdt_probe(struct i2c_client *client,
>  			return val;
>  		}
>  
> -		if (val < ZIIRAVE_TIMEOUT_MIN)
> -			return -ENODEV;
> -
> -		w_priv->wdd.timeout = val;
> -	} else {
> -		ret = ziirave_wdt_set_timeout(&w_priv->wdd,
> -					      w_priv->wdd.timeout);
> -		if (ret) {
> -			dev_err(&client->dev, "Failed to set timeout\n");
> -			return ret;
> -		}
> +		w_priv->wdd.timeout = clamp(val, ZIIRAVE_TIMEOUT_MIN,
> +					    ZIIRAVE_TIMEOUT_MAX);
> +	}
>  
> -		dev_info(&client->dev, "Timeout set to %ds\n",
> -			 w_priv->wdd.timeout);
> +	ret = ziirave_wdt_set_timeout(&w_priv->wdd, w_priv->wdd.timeout);
> +	if (ret) {
> +		dev_err(&client->dev, "Failed to set timeout\n");
> +		return ret;
>  	}
>  
> +	dev_info(&client->dev, "Timeout set to %ds\n", w_priv->wdd.timeout);
> +
>  	watchdog_set_nowayout(&w_priv->wdd, nowayout);
>  
>  	i2c_set_clientdata(client, w_priv);
> -- 
> 2.21.0
>
Andrey Smirnov Aug. 10, 2019, 9:17 p.m. UTC | #3
On Wed, Jul 31, 2019 at 11:09 AM Guenter Roeck <linux@roeck-us.net> wrote:
>
> On Wed, Jul 31, 2019 at 10:42:51AM -0700, Andrey Smirnov wrote:
> > Reprogramming bootloader on watchdog MCU will result in reported
> > default timeout value of "0". That in turn will be unnecesarily
>
> unnecessarily
>
> > rejected by the driver as invalid device (-ENODEV). Simplify probe to
> > just read stored timeout value, clamp it to an acceptable range and
> > program the value unconditionally to fix the above.
> >
> > Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
> > Cc: Chris Healy <cphealy@gmail.com>
> > Cc: Guenter Roeck <linux@roeck-us.net>
> > Cc: Rick Ramstetter <rick@anteaterllc.com>
> > Cc: linux-watchdog@vger.kernel.org
> > Cc: linux-kernel@vger.kernel.org
> > ---
> >  drivers/watchdog/ziirave_wdt.c | 22 +++++++++-------------
> >  1 file changed, 9 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/watchdog/ziirave_wdt.c b/drivers/watchdog/ziirave_wdt.c
> > index 89ce6982ba53..33c8d2eadada 100644
> > --- a/drivers/watchdog/ziirave_wdt.c
> > +++ b/drivers/watchdog/ziirave_wdt.c
> > @@ -667,22 +667,18 @@ static int ziirave_wdt_probe(struct i2c_client *client,
> >                       return val;
> >               }
> >
> > -             if (val < ZIIRAVE_TIMEOUT_MIN)
> > -                     return -ENODEV;
> > -
> > -             w_priv->wdd.timeout = val;
> > -     } else {
> > -             ret = ziirave_wdt_set_timeout(&w_priv->wdd,
> > -                                           w_priv->wdd.timeout);
> > -             if (ret) {
> > -                     dev_err(&client->dev, "Failed to set timeout\n");
> > -                     return ret;
> > -             }
> > +             w_priv->wdd.timeout = clamp(val, ZIIRAVE_TIMEOUT_MIN,
> > +                                         ZIIRAVE_TIMEOUT_MAX);
>
> Are you sure ? Effectively that will set the timeout to the minimum,
> ie three seconds. It might be better to define and set some default.
> Your call, of course.
>

It doesn't really matter in my use-case (set timeout is a no-op),  but
it sounds like a better approach, so I'll change it in v2.

Thanks,
Andrey Smirnov

Patch
diff mbox series

diff --git a/drivers/watchdog/ziirave_wdt.c b/drivers/watchdog/ziirave_wdt.c
index 89ce6982ba53..33c8d2eadada 100644
--- a/drivers/watchdog/ziirave_wdt.c
+++ b/drivers/watchdog/ziirave_wdt.c
@@ -667,22 +667,18 @@  static int ziirave_wdt_probe(struct i2c_client *client,
 			return val;
 		}
 
-		if (val < ZIIRAVE_TIMEOUT_MIN)
-			return -ENODEV;
-
-		w_priv->wdd.timeout = val;
-	} else {
-		ret = ziirave_wdt_set_timeout(&w_priv->wdd,
-					      w_priv->wdd.timeout);
-		if (ret) {
-			dev_err(&client->dev, "Failed to set timeout\n");
-			return ret;
-		}
+		w_priv->wdd.timeout = clamp(val, ZIIRAVE_TIMEOUT_MIN,
+					    ZIIRAVE_TIMEOUT_MAX);
+	}
 
-		dev_info(&client->dev, "Timeout set to %ds\n",
-			 w_priv->wdd.timeout);
+	ret = ziirave_wdt_set_timeout(&w_priv->wdd, w_priv->wdd.timeout);
+	if (ret) {
+		dev_err(&client->dev, "Failed to set timeout\n");
+		return ret;
 	}
 
+	dev_info(&client->dev, "Timeout set to %ds\n", w_priv->wdd.timeout);
+
 	watchdog_set_nowayout(&w_priv->wdd, nowayout);
 
 	i2c_set_clientdata(client, w_priv);