Regression: v4.0-rc1: iMX6: Hummingboard fails due to drivers/clk changes

[Olof Johansson]

On Mon, Feb 23, 2015 at 2:32 PM, Russell King - ARM Linux
<linux at arm.linux.org.uk> wrote:
> All,
>
> I just tried my SolidRun patch set on top of v4.0-rc1, and it fails to
> boot.  The kernel itself finishes booting, but it is unable to DHCP (for
> root-NFS) - nothing appears on the network.
>
> At first, I thought this would be a network driver bug, but reverting
> the mainline changes there didn't fix the regression.  Then I wondered
> if it was something in arch/arm/mach-imx, but no.
>
> When reverting all drivers/clk changes (and corresponding include/linux/*.h)
> between v3.19 and v4.0-rc1, I find that the regression is fixed.
>
> It seems that some CCF change is causing a regression somewhere in the
> clock tree on iMX6 CPUs.
>
> Unfortunately, without networking running, I can't dump the clock tree
> to find out what's different, and bisecting will be a major pain (needing
> each bisect point to be merged with my patch set, built and tested.)
>
> Has anyone else seen this?

FWIW, my hummingboard comes up with networking on v4.0-rc1 with
imx_v6_v7_defconfig and multi_v7:

http://arm-soc.lixom.net/bootlogs/mainline/v4.0-rc1/hummingboard-arm-imx_v6_v7_defconfig.html
http://arm-soc.lixom.net/bootlogs/mainline/v4.0-rc1/hummingboard-arm-multi_v7_defconfig.html

Which is unfortunate, since it'd be easy for me to bisect. :(


-Olof