Hi Anand On 2016-04-30 08:06, Anand Moon wrote:
Hi All, Using microSD card when I try to write into /dev/watchdog device it triggers reboot of the board after timer expires. ----------------------------------------------------------------------------------------------- root@odroidxu4l:~# echo 3 > /dev/watchdog [ 1659.021844] watchdog: watchdog0: watchdog did not stop! root@odroidxu4l:~# root@odroidxu4l:~# root@odroidxu4l:~# root@odroidxu4l:~# root@odroidxu4l:~# U-Boot 2016.03-00665-g563d8d9-dirty (Apr 04 2016 - 22:27:07 +0930) for ODROID-XU 3 CPU: Exynos5422 @ 800 MHz Model: Odroid XU3 based on EXYNOS5422 Board: Odroid XU3 based on EXYNOS5422 Type: xu4 DRAM: 2 GiB ----------------------------------------------------------------------------------------------- But when I try this on eMMC it just freezes. I know we have to set and unset gpio pin (SD_0.RST) to trigger reset before reboot. ----------------------------------------------------------------------------------------------- root@odroidxu4e:~# echo 4 > /dev/watchdog [ 639.192617] [c3] watchdog watchdog0: watchdog did not stop! root@odroidxu4e:~# root@odroidxu4e:~# root@odroidxu4e:~# ----------------------------------------------------------------------------------------------- I would like to know what is way board reset after watchdog reset after timeout.
In my opinion hw watchdog reset is non-functional on Odroid U3/XU3/XU4 boards due to hardware design (eMMC reset line triggered from software). I see no way to workaround
this issue in the software. Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html