Bug#794266: TS219P (Kirkwood 6281 variant) has same problem

[Manuel Roeder <manuel_roeder@gmx.de>]

I upgraded my debian from Wheezy to Stretch/SID and had the same problem
with poweroff. I talked to ukleinek on IRC-debian and had a few findings:

- problems seems to start with 4.x.x kernels

- testet 4.4.6, 4.4.7, 4.4.8 and actually 4.5.0-1-marvell

- problems has something to do with the build in real-time-clock of
  the QNAP or maybe with the i2c-bus it is connected to.

- another idea is that the problem has something to do with qcontrol

- if you check your kernel-log (dmesg | grep rtc)
  you will should see a wrong set alarm-time, this seems to be the
  fault:

  [    2.257418] rtc rtc0: invalid alarm value: 1900-1-29 1193031:57:16

- we unloaded the rtc (i2c)-driver and checked it with i2c tools

  echo 0-0030 > /sys/bus/i2c/devices/0-0030/driver/unbind

  i2c-detect -l
  i2c-detect 0

  i2cget 0 0x30 1
       [ 8555.228376] i2c i2c-0: mv64xxx_i2c_fsm: Ctlr Error
        -- state:  0x7, status: 0x38, addr: 0x30, flags: 0x1

- after rebooting the error was magically gone
  (I think the rtc is still not working / but alarm is unset)


Manuel