2020-05-27 04:36:19

by yuechao.zhao(赵越超)

Subject: [v1,1/1 1/2] Check the timeout module parameter is in the min-max range

From: Yuechao Zhao <[email protected]>

Check the return value of 'watchdog_init_timeout()' for checking the
timeout module parameter is in the min-max range.

Signed-off-by: Yuechao Zhao <[email protected]>
---
drivers/hwmon/nct7904.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/nct7904.c b/drivers/hwmon/nct7904.c
index 18c95be..d069d59 100644
--- a/drivers/hwmon/nct7904.c
+++ b/drivers/hwmon/nct7904.c
@@ -1152,7 +1152,10 @@ static int nct7904_probe(struct i2c_client *client,
data->wdt.max_timeout = MAX_TIMEOUT;
data->wdt.parent = &client->dev;

- watchdog_init_timeout(&data->wdt, timeout * 60, &client->dev);
+ ret = watchdog_init_timeout(&data->wdt, timeout * 60, &client->dev);
+ if (ret < 0)
+ return ret;
+
watchdog_set_nowayout(&data->wdt, nowayout);
watchdog_set_drvdata(&data->wdt, data);

--
1.8.3.1

2020-05-27 04:36:20

by yuechao.zhao(赵越超)

Subject: [v1,1/1 2/2] Set the default timeout

From: Yuechao Zhao <[email protected]>

The timeout module parameter should not be used for setting the default
timeout. Because, if you set the timeout = 0, the default timeout will
be meaningless. And the wahtchdog_init_timeout() can not detect this
error because the timeout module parameter of 0 means "no timeout
module paraameter specified".

Signed-off-by: Yuechao Zhao <[email protected]>
---
drivers/hwmon/nct7904.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwmon/nct7904.c b/drivers/hwmon/nct7904.c
index d069d59..ddbe47e 100644
--- a/drivers/hwmon/nct7904.c
+++ b/drivers/hwmon/nct7904.c
@@ -1147,7 +1147,7 @@ static int nct7904_probe(struct i2c_client *client,
data->wdt.ops = &nct7904_wdt_ops;
data->wdt.info = &nct7904_wdt_info;

- data->wdt.timeout = timeout * 60; /* in seconds */
+ data->wdt.timeout = WATCHDOG_TIMEOUT * 60; /* Set default timeout */
data->wdt.min_timeout = MIN_TIMEOUT;
data->wdt.max_timeout = MAX_TIMEOUT;
data->wdt.parent = &client->dev;
--
1.8.3.1

2020-05-27 04:51:50

by Guenter Roeck

Subject: Re: [v1,1/1 1/2] Check the timeout module parameter is in the min-max range

On 5/26/20 6:18 PM, [email protected] wrote:
> From: Yuechao Zhao <[email protected]>
>
> Check the return value of 'watchdog_init_timeout()' for checking the
> timeout module parameter is in the min-max range.
>
> Signed-off-by: Yuechao Zhao <[email protected]>

Please fix the subject. It should start with "hwmon: (nct7904)"

> ---
> drivers/hwmon/nct7904.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hwmon/nct7904.c b/drivers/hwmon/nct7904.c
> index 18c95be..d069d59 100644
> --- a/drivers/hwmon/nct7904.c
> +++ b/drivers/hwmon/nct7904.c
> @@ -1152,7 +1152,10 @@ static int nct7904_probe(struct i2c_client *client,
> data->wdt.max_timeout = MAX_TIMEOUT;
> data->wdt.parent = &client->dev;
>
> - watchdog_init_timeout(&data->wdt, timeout * 60, &client->dev);
> + ret = watchdog_init_timeout(&data->wdt, timeout * 60, &client->dev);
> + if (ret < 0)
> + return ret;
> +

Why ? The idea of returning an error from watchdog_init_timeout
is to give the driver a chance to select a default, not to refuse
loading the driver.

> watchdog_set_nowayout(&data->wdt, nowayout);
> watchdog_set_drvdata(&data->wdt, data);
>
>

2020-05-27 09:43:46

by Guenter Roeck

Subject: Re: [v1,1/1 2/2] Set the default timeout

On 5/26/20 6:18 PM, [email protected] wrote:
> From: Yuechao Zhao <[email protected]>
>
> The timeout module parameter should not be used for setting the default
> timeout. Because, if you set the timeout = 0, the default timeout will
> be meaningless. And the wahtchdog_init_timeout() can not detect this
> error because the timeout module parameter of 0 means "no timeout
> module paraameter specified".
>
> Signed-off-by: Yuechao Zhao <[email protected]>

Please fix the subject to something like "hmwmon: (nct7904) Set default timeout".

Also, the change only makes sense if you also change "static int timeout"
to default to 0. Then you can just drop patch 1/2.

Guenter

> ---
> drivers/hwmon/nct7904.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/hwmon/nct7904.c b/drivers/hwmon/nct7904.c
> index d069d59..ddbe47e 100644
> --- a/drivers/hwmon/nct7904.c
> +++ b/drivers/hwmon/nct7904.c
> @@ -1147,7 +1147,7 @@ static int nct7904_probe(struct i2c_client *client,
> data->wdt.ops = &nct7904_wdt_ops;
> data->wdt.info = &nct7904_wdt_info;
>
> - data->wdt.timeout = timeout * 60; /* in seconds */
> + data->wdt.timeout = WATCHDOG_TIMEOUT * 60; /* Set default timeout */
> data->wdt.min_timeout = MIN_TIMEOUT;
> data->wdt.max_timeout = MAX_TIMEOUT;
> data->wdt.parent = &client->dev;
>