lkml.org 
[lkml]   [2022]   [Apr]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] Watchdog: Checking timeout invalid if hardware heartbeat range is configured
On 4/21/22 07:22, Liu Xinpeng wrote:
> The timeout should be invalid when it is out of the hardware
> timeout range.
>
> ACPI watchdog: Using watchdog_timeout_invalid to check parameter
> timeout invalid
>
> Signed-off-by: Liu Xinpeng <liuxp11@chinatelecom.cn>
> ---
> drivers/watchdog/wdat_wdt.c | 3 +--
> include/linux/watchdog.h | 17 ++++++++++++-----
> 2 files changed, 13 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/watchdog/wdat_wdt.c b/drivers/watchdog/wdat_wdt.c
> index 195c8c004b69..d166d33ce7ae 100644
> --- a/drivers/watchdog/wdat_wdt.c
> +++ b/drivers/watchdog/wdat_wdt.c
> @@ -450,8 +450,7 @@ static int wdat_wdt_probe(struct platform_device *pdev)
> * watchdog properly after it has opened the device. In some cases
> * the BIOS default is too short and causes immediate reboot.
> */
> - if (timeout * 1000 < wdat->wdd.min_hw_heartbeat_ms ||
> - timeout * 1000 > wdat->wdd.max_hw_heartbeat_ms) {
> + if (watchdog_timeout_invalid(&wdat->wdd, timeout)) {
> dev_warn(dev, "Invalid timeout %d given, using %d\n",
> timeout, WDAT_DEFAULT_TIMEOUT);
> timeout = WDAT_DEFAULT_TIMEOUT;
> diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
> index 99660197a36c..e82daeef0b26 100644
> --- a/include/linux/watchdog.h
> +++ b/include/linux/watchdog.h
> @@ -167,6 +167,15 @@ static inline void watchdog_stop_ping_on_suspend(struct watchdog_device *wdd)
> /* Use the following function to check if a timeout value is invalid */
> static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, unsigned int t)
> {
> + /*
> + * If a maximum/minimum hardware timeout is configured,
> + * the timeout is invalid when it is out of the range.
> + */
> + if (wdd->max_hw_heartbeat_ms)
> + return t * 1000 > wdd->max_hw_heartbeat_ms;
> + if (wdd->min_hw_heartbeat_ms)
> + return t * 1000 < wdd->min_hw_heartbeat_ms;
> +

I have no idea what problem you are trying to solve, but this is
completely wrong: It defeats the purpose of having separate minimum
and maximum HW timeouts and configured timeout values. The watchdog
core takes care of those situations.

NACK.

Guenter

> /*
> * The timeout is invalid if
> * - the requested value is larger than UINT_MAX / 1000
> @@ -174,13 +183,11 @@ static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, unsigne
> * or
> * - the requested value is smaller than the configured minimum timeout,
> * or
> - * - a maximum hardware timeout is not configured, a maximum timeout
> - * is configured, and the requested value is larger than the
> - * configured maximum timeout.
> + * - maximum timeout is configured, and the requested value is larger than
> + * the configured maximum timeout.
> */
> return t > UINT_MAX / 1000 || t < wdd->min_timeout ||
> - (!wdd->max_hw_heartbeat_ms && wdd->max_timeout &&
> - t > wdd->max_timeout);
> + (wdd->max_timeout && t > wdd->max_timeout);
> }
>
> /* Use the following function to check if a pretimeout value is invalid */

\
 
 \ /
  Last update: 2022-04-21 23:11    [W:0.048 / U:0.392 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site