imx6 suspend/resume issue

[ben@datarespons.no (Bjørn Erik Nilsen)]

On Tue, 2013-12-10 at 13:56 +0100, Shawn Guo wrote:
> On Tue, Dec 10, 2013 at 01:21:20PM +0100, Bj?rn Erik Nilsen wrote:
> > Hi,
> > 
> > I have a nitrogen6x board (imx6q) from boundary devices and I've been
> > playing with power management on the 3.12 kernel.
> > 
> > There are issues related to suspend/resume. It looks like I can
> > successfully enter mem mode, however when I trigger one of the wakeup
> > sources I'm not able to resume successfully.
> 
> It might be a nitrogen6x specific problem, as 3.12 kernel works fine on
> my board (imx6q-sabresd).

I did more extensive testing around this and it turns out it actually
works like a charm when only the imx chip is powered (other power
domains shut down).

So the core part does indeed work.

> 
> root at arm:~# uname -a
> Linux arm 3.12.0 #3 SMP Tue Dec 10 20:45:32 CST 2013 armv7l GNU/Linux
> root at arm:~# echo mem > /sys/power/state
> PM: Syncing filesystems ... done.
> PM: Preparing system for mem sleep
> Freezing user space processes ... (elapsed 0.001 seconds) done.
> Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
> PM: Entering mem sleep
> PM: suspend of devices complete after 40.785 msecs
> PM: suspend devices took 0.040 seconds
> PM: late suspend of devices complete after 0.351 msecs
> PM: noirq suspend of devices complete after 0.521 msecs
> Disabling non-boot CPUs ...
> CPU1: shutdown
> CPU2: shutdown
> CPU3: shutdown
> Enabling non-boot CPUs ...
> CPU1: Booted secondary processor
> CPU1 is up
> CPU2: Booted secondary processor
> CPU2 is up
> CPU3: Booted secondary processor
> CPU3 is up
> PM: noirq resume of devices complete after 0.271 msecs
> PM: early resume of devices complete after 0.336 msecs
> ata1: SATA link down (SStatus 0 SControl 300)
> PM: resume of devices complete after 355.835 msecs
> PM: resume devices took 0.360 seconds
> PM: Finishing wakeup.
> Restarting tasks ... done.
> root at arm:~#
> 
> Shawn
> 
> > 
> > #echo mem > /sys/power/state
> > 
> > PM: Syncing filesystems ... done.
> > PM: Preparing system for mem sleep
> > Freezing user space processes ... (elapsed 0.001 seconds) done.
> > Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
> > PM: Entering mem sleep
> > PM: suspend of devices complete after 53.008 msecs
> > PM: suspend devices took 0.060 seconds
> > PM: late suspend of devices complete after 1.924 msecs
> > PM: noirq suspend of devices complete after 2.604 msecs
> > Disabling non-boot CPUs ...
> > CPU1: shutdown
> > CPU2: shutdown
> > CPU3: shutdown
> > 
> > <trigger wake-up source>
> > 
> > Enabling non-boot CPUs ...
> > CPU1: Booted secondary processor
> > CPU1 is up
> > CPU2: Booted secondary processor
> > CPU2 is up
> > CPU3: Booted secondary processor
> > CPU3 is up
> > 
> > And then the system hangs there. I have looked through recent patchwork
> > and I cannot find any obvious commits missing from my branch.
> > 
> > I'm thinking this must be a known issue and perhaps you can point me in
> > the right direction for what I should look for.
>