Re: [PATCH 1/5] watchdog: imx7ulp: Fix reboot hang

[Guenter Roeck <linux@roeck-us.net>]

On 11/4/19 5:45 AM, Fabio Estevam wrote:
> Hi Guenter,
> 
> On Sat, Nov 2, 2019 at 12:36 PM Guenter Roeck <linux@roeck-us.net> wrote:
>>
>> On Tue, Oct 29, 2019 at 02:40:33PM -0300, Fabio Estevam wrote:
>>> The following hang is observed when a 'reboot' command is issued:
>>>
>>> # reboot
>>> # Stopping network: OK
>>> Stopping klogd: OK
>>> Stopping syslogd: OK
>>> umount: devtmpfs busy - remounted read-only
>>> [    8.612079] EXT4-fs (mmcblk0p2): re-mounted. Opts: (null)
>>> The system is going down NOW!
>>> Sent SIGTERM to all processes
>>> Sent SIGKILL to all processes
>>> Requesting system reboot
>>> [   10.694753] reboot: Restarting system
>>> [   11.699008] Reboot failed -- System halted
>>>
>>> Fix this problem by adding a .restart ops member.
>>>
>>> Fixes: 41b630f41bf7 ("watchdog: Add i.MX7ULP watchdog support")
>>> Signed-off-by: Fabio Estevam <festevam@gmail.com>
>>
>> Reviewed-by: Guenter Roeck <linux@roeck-us.net>
>>
>> However, just to be sure: This registers the watchdog based restart handler
>> as restart handler of last resort. I assume this on purpose, I just want
>> to make sure it is intentional since it is not explicitly mentioned in
>> the commit message.
> 
> To be honest, I thought that registering the restart handler was mandatory.
> 
Maybe I should have said "there is no call to watchdog_set_restart_priority()".

> By the way, I have just noticed that even though this patch fixes the
> reboot on a imx7ulp evk board, it does not work on a imx7ulp com
> board.
> 
> I will debug this, so please discard this patch for now. The other
> ones of this series should be fine to apply.
> 

Thanks for the update.

Guenter