On 26.07.21 11:19, Mantas Mikulėnas wrote: > Hello, > > I have a Dell Inspiron 15-5547 laptop, with systemd configured to set > the watchdog to a 2-minute expiry (due to reasons): > > # /etc/systemd/system.conf > [Manager] > RuntimeWatchdogSec=2min > > So far this setting has worked without problems (including kernels > 5.12.15 and 5.13.1); however, with kernel 5.13.4 the system inevitably > reboots after a few minutes of uptime. > > I have tracked the issue down to commit 5e65819a006e "watchdog: > iTCO_wdt: Account for rebooting on second timeout" in the 5.13.x > branch (commit cb011044e34c upstream). There are no unexpected reboots > when running 5.13.4 with this commit reverted. > > Indeed with the original 5.13.4 kernel, `wdctl` always reports > "Timeleft:" counting down from 60 seconds (sometimes very nearly > reaching 0), even though "Timeout" is still reported to be 120. > > (systemd pokes the watchdog as part of its main loop, trying to so > approximately "between 1/4 and 1/2" of the configured interval. > According to wdctl these pings usually happen every 35-50 seconds but > sometimes nearly at the 60-second mark, and thanks to the kernel now > also dividing the requested expiry by /2 which systemd is unaware of, > sometimes this ends up being a *very* close race to 0.) > > This is a Haswell-era machine (i7-4510U) and seems to have a "version > 0" watchdog: > > Jul 26 11:34:04 archlinux kernel: Linux version 5.13.4-arch2-1 > (linux@archlinux) (gcc (GCC) 11.1.0, GNU ld (GNU Binutils) 2.36.1) #1 > SMP PREEMPT Thu, 22 Jul 2021 20:46:28 +0000 > Jul 26 11:34:14 frost kernel: iTCO_vendor_support: vendor-support=0 > Jul 26 11:34:14 frost kernel: iTCO_wdt iTCO_wdt.3.auto: Found a Lynx > Point_LP TCO device (Version=2, TCOBASE=0x1860) > Jul 26 11:34:14 frost systemd[1]: Using hardware watchdog 'iTCO_wdt', > version 0, device /dev/watchdog > Jul 26 11:34:14 frost systemd[1]: Set hardware watchdog to 2min. > Jul 26 11:34:14 frost kernel: iTCO_wdt iTCO_wdt.3.auto: initialized. > heartbeat=30 sec (nowayout=0) > Could you printk SMI_EN(p) in iTCO_wdt_set_timeout() (drivers/watchdog/iTCO_wdt.c)? This is where we decide whether SMIs are working, thus the countdown will only run once. Apparently, something is wrong with the detection on this system. Thanks, Jan -- Siemens AG, T RDA IOT Corporate Competence Center Embedded Linux
