On 26.07.21 11:40, Jan Kiszka wrote: > 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. > Wait, found it: diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c index b3f604669e2c..643c6c2d0b72 100644 --- a/drivers/watchdog/iTCO_wdt.c +++ b/drivers/watchdog/iTCO_wdt.c @@ -362,7 +362,7 @@ static int iTCO_wdt_set_timeout(struct watchdog_device *wd_dev, unsigned int t) * Otherwise, the BIOS generally reboots when the SMI triggers. */ if (p->smi_res && - (SMI_EN(p) & (TCO_EN | GBL_SMI_EN)) != (TCO_EN | GBL_SMI_EN)) + (inl(SMI_EN(p)) & (TCO_EN | GBL_SMI_EN)) != (TCO_EN | GBL_SMI_EN)) tmrval /= 2; /* from the specs: */ Hand me a brown paper bag... Jan -- Siemens AG, T RDA IOT Corporate Competence Center Embedded Linux
