NXP i.MX6UL Reboot Command Issue

[kunalbarot]

Hi, 
I'm using NXP i.MX6UL 698MHz ARM A7 Linux board.The problem I'm facing is w, if I issue the 'reboot' command on the serial console, device will begin the reboot sequence but hang at the end and not reboot.

See below log

---------------------------- 

Power on log

------------------------------

Debian GNU/Linux 8 ts-imx6ul ttymxc0

ts-imx6ul login:
1 USB Device(s) found
scanning usb for storage devices... 0 Storage Device(s) found
No storage devices, perhaps not 'usb start'ed..?
Booting from the eMMC ...
** File not found /boot/boot.ub **
32814 bytes read in 117 ms (273.4 KiB/s)
6852056 bytes read in 422 ms (15.5 MiB/s)
Kernel image @ 0x80800000 [ 0x000000 - 0x688dd8 ]
## Flattened Device Tree blob at 83000000
Booting using the fdt blob at 0x83000000
Using Device Tree in place at 83000000, end 8300b02d

Starting kernel ...

Welcome to Debian GNU/Linux 8 (jessie)!

[ SKIP ] Ordering cycle found, skipping LSB: RPC portmapper replacement
Expecting device dev-ttymxc0.device...
[ OK ] Reached target Remote File Systems (Pre).
[ OK ] Set up automount Arbitrary Executable File Formats F...utomount Point.
[ OK ] Reached target Paths.
[ OK ] Reached target Encrypted Volumes.
[ OK ] Reached target Swap.
[ OK ] Created slice Root Slice.
[ OK ] Listening on /dev/initctl Compatibility Named Pipe.
[ OK ] Listening on Delayed Shutdown Socket.
[ OK ] Listening on Journal Socket (/dev/log).
[ OK ] Created slice User and Session Slice.
[ OK ] Listening on udev Control Socket.
[ OK ] Listening on udev Kernel Socket.
[ OK ] Listening on Journal Socket.
[ OK ] Created slice System Slice.
Mounting Temporary Directory...
Starting Increase datagram queue length...
Mounting Debug File System...
Starting Create list of required static device nodes...rrent kernel...
Starting udev Coldplug all Devices...
[ OK ] Created slice system-getty.slice.
[ OK ] Created slice system-serial\x2dgetty.slice.
Starting Collect Read-Ahead Data...
Starting LSB: NFS support files common to client and server...
[ OK ] Reached target Slices.
[ OK ] Mounted Temporary Directory.
[ OK ] Mounted Debug File System.
[ OK ] Started Increase datagram queue length.
[ OK ] Started Create list of required static device nodes ...current kernel.
[ OK ] Started Collect Read-Ahead Data.
[ OK ] Started LSB: NFS support files common to client and server.
[ OK ] Started udev Coldplug all Devices.
Starting Load Kernel Modules...
Starting Create Static Device Nodes in /dev...
[ OK ] Listening on Syslog Socket.
Starting Journal Service...
[ OK ] Started Journal Service.
[ OK ] Started Load Kernel Modules.
Starting Apply Kernel Variables...
Mounting FUSE Control File System...
[ OK ] Started Create Static Device Nodes in /dev.
[ OK ] Started Apply Kernel Variables.
[ OK ] Mounted FUSE Control File System.
Starting udev Kernel Device Manager...
[ OK ] Started udev Kernel Device Manager.
Starting Copy rules generated while the root was ro...
Starting LSB: Set preliminary keymap...
[ OK ] Started Copy rules generated while the root was ro.
[ OK ] Started LSB: Set preliminary keymap.
Starting Remount Root and Kernel File Systems...
[ OK ] Started Remount Root and Kernel File Systems.
Starting Load/Save Random Seed...
[ OK ] Reached target Local File Systems (Pre).
Mounting /var/volatile...
[ OK ] Started Load/Save Random Seed.
[ OK ] Mounted /var/volatile.
[ OK ] Reached target Local File Systems.
Starting Create Volatile Files and Directories...
Starting LSB: Raise network interfaces....
[ OK ] Reached target Remote File Systems.
Starting Trigger Flushing of Journal to Persistent Storage...
Starting LSB: Set console font and keymap...
[ OK ] Started LSB: Set console font and keymap.
[ OK ] Started Create Volatile Files and Directories.
[ OK ] Started Trigger Flushing of Journal to Persistent Storage.
[ OK ] Found device /dev/ttymxc0.
Starting Update UTMP about System Boot/Shutdown...
[ OK ] Started Update UTMP about System Boot/Shutdown.
[ OK ] Started LSB: Raise network interfaces..
[ OK ] Reached target System Initialization.
[ OK ] Listening on OpenBSD Secure Shell server socket.
[ OK ] Listening on saned incoming socket.
[ OK ] Listening on D-Bus System Message Bus Socket.
[ OK ] Reached target Sockets.
[ OK ] Reached target Timers.
Starting Restore Sound Card State...
[ OK ] Reached target Basic System.
Starting Daemon for power management...
Starting System Logging Service...
Starting Regen SSH keys on startup if they don't exist...
[ OK ] Started Regen SSH keys on startup if they don't exist.
Starting Restore /etc/resolv.conf if the system cras...s shut down....
Starting Regular background program processing daemon...
[ OK ] Started Regular background program processing daemon.
Starting WPA supplicant...
Starting D-Bus System Message Bus...
[ OK ] Started D-Bus System Message Bus.
[ OK ] Started WPA supplicant.
Starting Network Service...
Starting Login Service...
[ OK ] Started System Logging Service.
[ OK ] Started Restore Sound Card State.
[ OK ] Started Restore /etc/resolv.conf if the system crash...was shut down..
[ OK ] Started Network Service.
[ OK ] Started Daemon for power management.
Starting Network Name Resolution...
[ OK ] Reached target Network.
Starting Lighttpd Daemon...
Starting /etc/rc.local Compatibility...
Starting Permit User Sessions...
[ OK ] Reached target Network is Online.
Starting LSB: Advanced IEEE 802.11 management daemon...
Starting LSB: RPC portmapper replacement...
[ OK ] Started /etc/rc.local Compatibility.
[ OK ] Started Permit User Sessions.
[ OK ] Started LSB: Advanced IEEE 802.11 management daemon.
[ OK ] Started Network Name Resolution.
[ OK ] Started Login Service.
Starting (null)...
Starting SLiM Simple Login Manager...
Starting Getty on tty1...
[ OK ] Started Getty on tty1.
Starting Serial Getty on ttymxc0...
[ OK ] Started Serial Getty on ttymxc0.
[ OK ] Reached target Login Prompts.
[ OK ] Started SLiM Simple Login Manager.
[ OK ] Started LSB: RPC portmapper replacement.
[ OK ] Reached target RPC Port Mapper.
[ OK ] Started Lighttpd Daemon.
Stopping SLiM Simple Login Manager...
[ OK ] Stopped SLiM Simple Login Manager.
Starting SLiM Simple Login Manager...
[ OK ] Started SLiM Simple Login Manager.

Debian GNU/Linux 8 ts-imx6ul ttymxc0

ts-imx6ul login: root
Password: XXXXXXXXX

Last login: Tue Jun 27 15:11:52 UTC 2017 from 199.199.50.159 on pts/0
Linux ts-imx6ul 4.1.15-gbdce13f #32 SMP PREEMPT Thu Mar 16 11:37:03 PDT 2017 armv7l

The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
root@ts-imx6ul:~# reboot

---------------------------- 

Reboot Command applied here

------------------------------

Starting Synchronise Hardware Clock to System Clock...
[ OK ] Stopped target Swap.
[ OK ] Stopped target Encrypted Volumes.
[ OK ] Stopped Update UTMP about System Runlevel Changes.
Stopping Update UTMP about System Boot/Shutdown...
Stopping LSB: NFS support files common to client and server...
Stopping User Manager for UID 0...
[ OK ] Stopped target Graphical Interface.
Stopping Daemon for power management...
[ OK ] Stopped target Multi-User System.
Stopping Network Name Resolution...
Stopping Lighttpd Daemon...
Stopping System Logging Service...
Stopping Regular background program processing daemon...
[ OK ] Stopped target Login Prompts.
Stopping Getty on tty1...
Stopping Serial Getty on ttymxc0...
Stopping (null)...
Starting Store Sound Card State...
[ OK ] Stopped Daemon for power management.
[ OK ] Stopped Regular background program processing daemon.
[ OK ] Stopped Network Name Resolution.
[ OK ] Stopped (null).
[ OK ] Stopped Getty on tty1.
[ OK ] Stopped Serial Getty on ttymxc0.
[ OK ] Stopped Lighttpd Daemon.
[ OK ] Stopped System Logging Service.
[ OK ] Stopped User Manager for UID 0.
[ OK ] Stopped Update UTMP about System Boot/Shutdown.
[FAILED] Failed to start Store Sound Card State.
See 'systemctl status alsa-store.service' for details.
[ OK ] Stopped LSB: NFS support files common to client and server.
[ OK ] Started Synchronise Hardware Clock to System Clock.
[ OK ] Stopped User Manager for UID 0.
[ OK ] Stopped target RPC Port Mapper.
Stopping LSB: RPC portmapper replacement...
Stopping Create Volatile Files and Directories...
[ OK ] Stopped Create Volatile Files and Directories.
Stopping Login Service...
[ OK ] Removed slice user-0.slice.
[ OK ] Removed slice system-serial\x2dgetty.slice.
[ OK ] Removed slice system-getty.slice.
Stopping /etc/rc.local Compatibility...
[ OK ] Stopped /etc/rc.local Compatibility.
Stopping Permit User Sessions...
Stopping LSB: Advanced IEEE 802.11 management daemon...
[ OK ] Stopped Login Service.
[ OK ] Stopped LSB: RPC portmapper replacement.
[ OK ] Stopped Permit User Sessions.
[ OK ] Stopped LSB: Advanced IEEE 802.11 management daemon.
[ OK ] Stopped target Remote File Systems.
[ OK ] Stopped target Remote File Systems (Pre).
[ OK ] Stopped target Network is Online.
[ OK ] Stopped target Network.
Stopping LSB: Raise network interfaces....
Stopping Network Service...
[ OK ] Stopped Network Service.
Stopping D-Bus System Message Bus...
[ OK ] Stopped D-Bus System Message Bus.
[ OK ] Stopped target Basic System.
[ OK ] Stopped target Slices.
[ OK ] Removed slice User and Session Slice.
[ OK ] Stopped target Paths.
[ OK ] Stopped target Timers.
[ OK ] Stopped target Sockets.
[ OK ] Closed OpenBSD Secure Shell server socket.
[ OK ] Closed saned incoming socket.
[ OK ] Closed Syslog Socket.
[ OK ] Closed D-Bus System Message Bus Socket.
[ OK ] Stopped LSB: Raise network interfaces..
Stopping Apply Kernel Variables...
[ OK ] Stopped Apply Kernel Variables.
Stopping Load Kernel Modules...
[ OK ] Stopped Load Kernel Modules.
Stopping Load/Save Random Seed...
[ OK ] Stopped target Local File Systems.
Unmounting /run/user/0...
Unmounting Temporary Directory...
Unmounting /var/volatile...
[ OK ] Stopped Load/Save Random Seed.
[ OK ] Unmounted /run/user/0.
[ OK ] Unmounted Temporary Directory.
[ OK ] Unmounted /var/volatile.
[ OK ] Reached target Unmount All Filesystems.
[ OK ] Stopped target Local File Systems (Pre).
Stopping Create Static Device Nodes in /dev...
[ OK ] Stopped Create Static Device Nodes in /dev.
Stopping Remount Root and Kernel File Systems...
[ OK ] Stopped Remount Root and Kernel File Systems.
Stopping Collect Read-Ahead Data...
[ OK ] Stopped Collect Read-Ahead Data.
[ OK ] Reached target Shutdown.
[ OK ] Reached target Final Step.
Starting Reboot...
watchdog watchdog0: watchdog did not stop!
imx2-wdt 20bc000.wdog: Device shutdown: Expect reboot!
reboot: Restarting system

---------------------------- 

Board never boot again after this

------------------------------

[igorpadykov]

Hi Kunal

please check that on board wdog signal toggle all board power as

it is implemented in i.MX6UL EVK schematic (SPF-28617) U708 (UM805)

Schematics (1)
MCIMX6UL-EVK_DESIGNFILES
Design files, including hardware schematics, Gerbers, and OrCAD files. (REV 0)
http://www.nxp.com/products/sensors/gyroscopes/i.mx6ultralite-evaluation-kit:MCIMX6UL-EVK?fpsp=1&tab...

Reason is that cpufreq driver may lower procesor voltages, so at reboot time it will

be insufficient for normal boot.

Best regards
igor
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[huabobao]

Hi，igorpadykov！

I have a similar  question. using u-boot ，I can reset imx6ul with wotchdog1,but linux cannot !

     Can you tell me why?

     BTW,you say:

      Reason is that cpufreq driver may lower procesor voltages, so at reboot time it will

      be insufficient for normal boot

     Is there some software way to solve the problem?

   TKS!

[igorpadykov]

one can try to disable cpufreq driver so processor voltages were not

changed, then perform reset.

Best regards
igor

[huabobao]

Hi igor

Last nignt I do some operations as bellow:

you see,the cpufreq become highest,but  when i do reset(using watchdog timeout  way),the linux system suspend ,still not resset.

so I have some questions:

1. the above operations meet your suggestion ，"try to disable cpufreq driver" ?

2. Since u-boot can do reset ,can you tell me what addional setting in linux ,so it  failed to reset ?

Look forward to your favourable reply！

[igorpadykov]

please verify that before reset VDD_SOC_IN, VDD_ARM_CAP voltages described

in Table 11. Operating Ranges i.MX6UL Datasheet are for 528MHz operation

http://cache.freescale.com/files/32bit/doc/data_sheet/IMX6ULCEC.pdf

There are no addional settings in linux preventing  failing to reset, it is necessary to make

in hardware.

Best regards
igor

[huabobao]

Hi igor

I have verify the above idea,It still hangs.

Since u-boot can do reset , is there some other idea for me? 

TKS  ！

[igorpadykov]

except that reason there may be many others why it is not reset in linux.

What type of memory used in the case, what boot device ? What about

other peripherals, if these are not reset with total power board reset, they may

stay in non-reset state and prevent successful reboot. One can try with

minimal configuration, removing all drivers to check that. Ideally all i.MX6 signals

connected to some peripherals should be analyzed for potential signal contention

using soft reset, because for example linux driver configures peripheral as output connected

to i.MX6 input, after soft reset that i.MX6 signal may become output, but peripheral

may stay output too (while after total power board reset it would become tri-state or input).

Best regards
igor

[huabobao]

Hi igor

I have verify the VDD_SOC_IN, VDD_ARM_CAP voltages before reset，They meets the  voltages described in Table 11.

when I use 528MHz ,the VDD_ARM_CAP is 1.2V ( the Table 11 from 1.15V to 1.3V),but when I do reset ,the linux system hangs and the  VDD_ARM_CAP change to 1.17V .

BTW,when I do reset in u-boot,the VDD_ARM_CAP is also 1.17V . 

Do you think that  the two 1.17V is coincidental ？ I have a idea ,can I adjust the VDD_ARM_CAP to 1.17V ? How can I do that?