Unable to boot mainline on snow chromebook since 3.15

[Will Deacon <will.deacon@arm.com>]

Hi all,

I'm one of the few, foolish people to try running mainline on my 5250-based
Samsung Chromebook (snow). I can live without wireless, usb3 and video
acceleration, so actually it makes a reasonable development platform for
doing A15-based (micro)-architectural work.

However, since 3.15 I've not been able to boot *any* mainline kernels on
this board. I did mean to report this earlier, but I have other machines
that can run mainline so this has fallen by the wayside.

The problems started with 3.16, where simple-fb would fail to initialise
and I lost my display. Note that I don't have a serial console on this
machine (I looked at the PCB and there's no way I can solder one of those
myself :) I bisected the issue at the time, and I could get my display back
by removing some of the new regulator and hdmi properties from the DT. At
that point, I could boot, but DMA didn't initialise for the MMC controller
so I couldn't mount my root filesystem.

With 3.17-rc3, it seems a lot worse -- I don't get any output after nv-uboot
(i.e. the nv-uboot screen just remains on the display, with the last line
reading "Stashed 20 records").

I'd usually try to debug this a bit further, but without a console it's
really painful to get anywhere. I've been working with 3.15, but now I'm
having to backport patches when I want to test them, which is more effort
than I can be bothered with.

Is anybody else running mainline on this device and are these known/fixed
problems?

Cheers,

Will