[BUG] PandaBoard hangs before starting init while booting v3.12

[tony@atomide.com (Tony Lindgren)]

* Chao Xu <caesarxuchao@gmail.com> [131122 19:28]:
> "I wonder if we also have some dependency to some earlier versions of
> u-boot as u-boot now only muxes the essential pins?"
> This is exactly the problem in my case. I added "#define
> CONFIG_SYS_ENABLE_PADS_ALL" in u-boot/include/configs/omap4_common.h
> and now there is output.
> 
> I guess the reason that the u-boot worked out-of-box for Ben but not
> for me is that I missed some configurations in v3.12 kernel. I image
> there is a config options that tells the kernel to take care of the
> non-essential pins that used to be the responsibility of u-boot. Could
> you confirm my hypothesis? And if so, could you kindly suggest what's
> the name of the config option?

That would be CONFIG_PINCTRL_SINGLE=y for device tree based omaps.
But if we have the configuration missing for some driver in the
board specific .dts file, that won't help naturally. We do have
PINCTRL_SINGLE enabled in omap2plus_defconfig.

Regards,

Tony