From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> Prominent userspace - systemd - cannot handle watchdogs without WDIOF_SETTIMEOUT, even if it was configured to the same time as the driver selected or was used by firmware to start the watchdog. To avoid failing in this case, implement a handler that only fails if a deviating set_timeout is requested. Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> --- See also https://github.com/systemd/systemd/issues/20683 drivers/watchdog/rti_wdt.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c index 359302f71f7e..365255b15a0d 100644 --- a/drivers/watchdog/rti_wdt.c +++ b/drivers/watchdog/rti_wdt.c @@ -173,13 +173,27 @@ static unsigned int rti_wdt_get_timeleft_ms(struct watchdog_device *wdd) return timer_counter; } +static int rti_wdt_set_timeout(struct watchdog_device *wdd, + unsigned int timeout) +{ + /* + * Updating the timeout after start is actually not supported, but + * let's ignore requests for the already configured value. Helps + * existing userspace such as systemd. + */ + if (timeout != heartbeat) + return -EOPNOTSUPP; + + return 0; +} + static unsigned int rti_wdt_get_timeleft(struct watchdog_device *wdd) { return rti_wdt_get_timeleft_ms(wdd) / 1000; } static const struct watchdog_info rti_wdt_info = { - .options = WDIOF_KEEPALIVEPING, + .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT, .identity = "K3 RTI Watchdog", }; @@ -187,6 +201,7 @@ static const struct watchdog_ops rti_wdt_ops = { .owner = THIS_MODULE, .start = rti_wdt_start, .ping = rti_wdt_ping, + .set_timeout = rti_wdt_set_timeout, .get_timeleft = rti_wdt_get_timeleft, }; -- 2.31.1
