Andy,

On Thu, Oct 30, 2014 at 1:11 AM, fugang.duan@freescale.com
[off-list ref] wrote:

I tried it yesterday with FEC close, resume cannot back.
I will try it again.

We have a regression in 3.18-rc1: if I use the imx6sx-sdb.dtb from
3.17.1 then I get:

root@freescale /$ echo enabled > /sys/class/tty/ttymxc0/power/wakeup
root@freescale /$ echo mem > /sys/power/state
[   13.883094] PM: Syncing filesystems ... done.
[   13.932184] Freezing user space processes ... (elapsed 0.003 seconds) done.
[   13.942928] Freezing remaining freezable tasks ... (elapsed 0.003 seconds) d.
[   14.014823] PM: suspend of devices complete after 54.572 msecs
[   14.020730] PM: suspend devices took 0.060 seconds
[   14.035241] PM: late suspend of devices complete after 9.545 msecs
[   14.050901] PM: noirq suspend of devices complete after 9.383 msecs
[   14.057626] Disabling non-boot CPUs ...
[   14.071514] PM: noirq resume of devices complete after 8.338 msecs
[   14.085645] PM: early resume of devices complete after 6.417 msecs
[   14.097720] fec 2188000.ethernet eth0: rcv is not +last
[   14.187491] PM: resume of devices complete after 95.494 msecs
[   14.199039] PM: resume devices took 0.100 seconds
[   14.203831] Restarting tasks ... done.
[   15.892318] fec 2188000.ethernet eth0: rcv is not +last
[   15.897688] fec 2188000.ethernet eth0: rcv is not +last
[   15.903010] fec 2188000.ethernet eth0: rcv is not +last
[   15.908326] fec 2188000.ethernet eth0: rcv is not +last
[   15.913635] fec 2188000.ethernet eth0: rcv is not +last
[   15.918945] fec 2188000.ethernet eth0: rcv is not +last

So fec suspend/resume is broken for mx6sx.

Please take a look at it.