Hi, After updating the kernel from 5.8.17 to 5.11 systemd (246.6) is unable to init watchdog in pcf2127 during boot. Kernel option CONFIG_WATCHDOG_OPEN_TIMEOUT=300 is working as expected. It's possible to get watchdog from userspace working in the following 2 ways. 1) Disable watchdog in systemd and use busybox watchdog. 2) Restart systemd after boot with "kill 1". During boot setting the system clock from RTC is working. RTC read/write from userland with hwclock is also working. DTS: imx7d-flex-concentrator-mfg.dts SOC: NXP i.MX7D Drivers: rtc-pcf2127, spi-imx Communication: SPI There are no patches applied to the kernel. When systemd changes watchdog timeout it receives an error that to our best knowledge comes from spi-imx[1]. We suspect it's a race condition between drivers or incompatible error handling. Any help in investigating the issue is appreciated. /Bruno [1] https://elixir.bootlin.com/linux/v5.11/source/drivers/spi/spi-imx.c#L1424 Relevant boot trace of pcf2127 and systemd: Feb 18 09:26:46 tqma7 kernel: rtc-pcf2127-spi spi1.0: pcf2127_probe Feb 18 09:26:46 tqma7 kernel: rtc-pcf2127-spi spi1.0: pcf2127_rtc_read_time: raw data is cr3=08, sec=37, min=26, hr=09, mday=18, wday=04, mon=02, year=21 Feb 18 09:26:46 tqma7 kernel: rtc-pcf2127-spi spi1.0: pcf2127_rtc_read_time: tm is secs=37, mins=26, hours=9, mday=18, mon=1, year=121, wday=4 Feb 18 09:26:46 tqma7 kernel: rtc-pcf2127-spi spi1.0: char device (252:0) Feb 18 09:26:46 tqma7 kernel: rtc-pcf2127-spi spi1.0: registered as rtc0 Feb 18 09:26:46 tqma7 kernel: rtc-pcf2127-spi spi1.0: pcf2127_rtc_read_time: raw data is cr3=08, sec=37, min=26, hr=09, mday=18, wday=04, mon=02, year=21 Feb 18 09:26:46 tqma7 kernel: rtc-pcf2127-spi spi1.0: pcf2127_rtc_read_time: tm is secs=37, mins=26, hours=9, mday=18, mon=1, year=121, wday=4 Feb 18 09:26:46 tqma7 kernel: rtc-pcf2127-spi spi1.0: setting system clock to 2021-02-18T09:26:37 UTC (1613640397) Feb 18 09:26:46 tqma7 kernel: rtc-pcf2127-spi spi1.0: I/O Error in PIO Feb 18 09:26:46 tqma7 kernel: rtc-pcf2127-spi spi1.0: SPI transfer failed: -110 Feb 18 09:26:46 tqma7 kernel: spi_master spi1: failed to transfer one message from queue Feb 18 09:26:46 tqma7 kernel: rtc-pcf2127-spi spi1.0: I/O Error in PIO Feb 18 09:26:46 tqma7 kernel: rtc-pcf2127-spi spi1.0: SPI transfer failed: -110 Feb 18 09:26:46 tqma7 kernel: spi_master spi1: failed to transfer one message from queue Feb 18 09:26:46 tqma7 systemd[1]: Hardware watchdog 'NXP PCF2127/PCF2129 Watchdog', version 0 Feb 18 09:26:46 tqma7 kernel: rtc-pcf2127-spi spi1.0: new watchdog timeout: 120s (old: 60s) Feb 18 09:26:46 tqma7 kernel: rtc-pcf2127-spi spi1.0: I/O Error in PIO Feb 18 09:26:46 tqma7 kernel: rtc-pcf2127-spi spi1.0: SPI transfer failed: -110 Feb 18 09:26:46 tqma7 kernel: spi_master spi1: failed to transfer one message from queue Feb 18 09:26:46 tqma7 kernel: rtc-pcf2127-spi spi1.0: pcf2127_wdt_active_ping: watchdog restart failed, ret=-110 Feb 18 09:26:46 tqma7 systemd[1]: Failed to set timeout to 120s: Connection timed out Relevant trace after systemd restart (kill 1): Feb 02 10:42:39 tqma7 kernel: watchdog: watchdog0: nowayout prevents watchdog being stopped! Feb 02 10:42:39 tqma7 kernel: watchdog: watchdog0: nowayout prevents watchdog being stopped! Feb 02 10:42:39 tqma7 kernel: watchdog: watchdog0: watchdog did not stop! Feb 02 10:42:39 tqma7 systemd[1]: systemd 246.6 running in system mode. (-PAM -AUDIT -SELINUX -IMA -APPARMOR -SMACK -SYSVINIT -UTMP -LIBCRYPTSETUP -GCRYPT -GNUTLS -ACL +XZ -LZ4 +ZSTD +SECCOMP +BLKID +ELFUTILS +KMOD -IDN2 -IDN -PCRE2 default-hierarchy=unified) Feb 02 10:42:39 tqma7 systemd[1]: Detected architecture arm. Feb 02 10:42:40 tqma7 systemd[1]: Hardware watchdog 'NXP PCF2127/PCF2129 Watchdog', version 0 Feb 02 10:42:40 tqma7 kernel: rtc-pcf2127-spi spi1.0: new watchdog timeout: 30s (old: 30s) Feb 02 10:42:40 tqma7 systemd[1]: Set hardware watchdog to 30s.
