On 06/26/2012 08:37 PM, Kevin Hilman wrote:

"Franky Lin" [off-list ref] writes:

quoted

I noticed Kevin raised some similar cases on other platforms and also
provided two patches in the patch mail thread. But unfortunately those
two patches doesn't help in our case. I tested the driver with 3.5-rc3
mainline kernel and the issue is still there. I can only "fix" the
hang by either reverting the commit or disabling
CONFIG_PM_RUNTIME. Also, the hang only happens on Panda ES board. Old
Panda with 4430 works good.

Any thoughts and suggestions?

If reverting the patch fixes your problem, can you isolate down to which
part of that patch causes the problem?  IOW, can you fix your problem if
you undo just the hunk added in runtime_suspend or undo just the moved
hunk runtime_resume?  Or is reverting both required?

I suspect the added runtime_suspend hunk is causing the problems, so can
you see if just undoing that part works[1].  If that works, I will give
a bit more of a thinking on it tomorrow.

runtime_suspend hunk is fine. The hang still exist after reverting it. 
The culprit is the moved hunk in runtime_resume. Reverting it makes the 
hang disappear.

Thanks for reporting the problem!   Bug reports like this that have
clearly been thoroughly researched and bisected are greatly appreciated!

Kevin

You are welcome.

Regards,
Franky