2022-02-12 19:17:18

by Eduardo Valentin

[permalink] [raw]
Subject: [PATCH 1/1] watchdog: aspeed: add nowayout support

Add support for not stopping the watchdog
when the userspace application quits. At
closing of the device, the driver cannot
determine if this was a graceful closure
or if the app crashed. If the support
of nowayout on this driver, the system integrator
can select the behaviour by setting the kernel
config and enabling it.

Cc: Wim Van Sebroeck <[email protected]> (maintainer:WATCHDOG DEVICE DRIVERS)
Cc: Guenter Roeck <[email protected]> (maintainer:WATCHDOG DEVICE DRIVERS)
Cc: Joel Stanley <[email protected]> (supporter:ARM/ASPEED MACHINE SUPPORT)
Cc: Andrew Jeffery <[email protected]> (reviewer:ARM/ASPEED MACHINE SUPPORT)
Cc: [email protected] (open list:WATCHDOG DEVICE DRIVERS)
Cc: [email protected] (moderated list:ARM/ASPEED MACHINE SUPPORT)
Cc: [email protected] (moderated list:ARM/ASPEED MACHINE SUPPORT)
Cc: [email protected] (open list)
Signed-off-by: Eduardo Valentin <[email protected]>
Signed-off-by: Eduardo Valentin <[email protected]>
---
drivers/watchdog/aspeed_wdt.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c
index 436571b6fc79..bd06622813eb 100644
--- a/drivers/watchdog/aspeed_wdt.c
+++ b/drivers/watchdog/aspeed_wdt.c
@@ -13,6 +13,11 @@
#include <linux/platform_device.h>
#include <linux/watchdog.h>

+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
struct aspeed_wdt {
struct watchdog_device wdd;
void __iomem *base;
@@ -266,6 +271,8 @@ static int aspeed_wdt_probe(struct platform_device *pdev)
wdt->wdd.timeout = WDT_DEFAULT_TIMEOUT;
watchdog_init_timeout(&wdt->wdd, 0, dev);

+ watchdog_set_nowayout(&wdt->wdd, nowayout);
+
np = dev->of_node;

ofdid = of_match_node(aspeed_wdt_of_table, np);
--
2.17.1


2022-02-12 23:15:46

by Guenter Roeck

[permalink] [raw]
Subject: Re: [PATCH 1/1] watchdog: aspeed: add nowayout support

On 2/11/22 18:10, Eduardo Valentin wrote:
> Add support for not stopping the watchdog
> when the userspace application quits. At
> closing of the device, the driver cannot
> determine if this was a graceful closure
> or if the app crashed. If the support
> of nowayout on this driver, the system integrator
> can select the behaviour by setting the kernel
> config and enabling it.
>
> Cc: Wim Van Sebroeck <[email protected]> (maintainer:WATCHDOG DEVICE DRIVERS)
> Cc: Guenter Roeck <[email protected]> (maintainer:WATCHDOG DEVICE DRIVERS)
> Cc: Joel Stanley <[email protected]> (supporter:ARM/ASPEED MACHINE SUPPORT)
> Cc: Andrew Jeffery <[email protected]> (reviewer:ARM/ASPEED MACHINE SUPPORT)
> Cc: [email protected] (open list:WATCHDOG DEVICE DRIVERS)
> Cc: [email protected] (moderated list:ARM/ASPEED MACHINE SUPPORT)
> Cc: [email protected] (moderated list:ARM/ASPEED MACHINE SUPPORT)
> Cc: [email protected] (open list)
> Signed-off-by: Eduardo Valentin <[email protected]>
> Signed-off-by: Eduardo Valentin <[email protected]>

Reviewed-by: Guenter Roeck <[email protected]>

> ---
> drivers/watchdog/aspeed_wdt.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c
> index 436571b6fc79..bd06622813eb 100644
> --- a/drivers/watchdog/aspeed_wdt.c
> +++ b/drivers/watchdog/aspeed_wdt.c
> @@ -13,6 +13,11 @@
> #include <linux/platform_device.h>
> #include <linux/watchdog.h>
>
> +static bool nowayout = WATCHDOG_NOWAYOUT;
> +module_param(nowayout, bool, 0);
> +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
> + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
> +
> struct aspeed_wdt {
> struct watchdog_device wdd;
> void __iomem *base;
> @@ -266,6 +271,8 @@ static int aspeed_wdt_probe(struct platform_device *pdev)
> wdt->wdd.timeout = WDT_DEFAULT_TIMEOUT;
> watchdog_init_timeout(&wdt->wdd, 0, dev);
>
> + watchdog_set_nowayout(&wdt->wdd, nowayout);
> +
> np = dev->of_node;
>
> ofdid = of_match_node(aspeed_wdt_of_table, np);