4.10-rc3 rpi issues

[Gerd Hoffmann]

  Hi,

> Very interesting here...  This isn't related directly to your specific
> issue but I'm finding that when I build this kernel with the exact
> dot.config you sent out with the arm-linux-gnueabihf- compiler it boots
> just fine on a RPI 2 but it completely fails to boot on a RPI 3.  In
> both cases this is with the armhf version of debian sid.  Meaning I
> just took the SD card out of the RPI 2 and put it in the RPI 3.

Could be this one missing:

https://www.kraxel.org/cgit/linux/commit/?h=bcm2837-base&id=a2673ddd07e9e1786d27e6ede8ba0781b1509bb1

Guess I should (re-)send this (and some other patches) quickly.
Got sidetracked with debugging this usb thing ...

> I thought the RPI 3 was 100% backward compatible with the RPI 2 from a
> hardware point of view?

Has a separate device tree though, and if that isn't there ...

Also the HDMI detect is wired a bit differently, and the gpio mux driver
to access it on the pi3 didn't land upstream yet.  So you have to play
some tricks for vc4, like this one:

https://www.kraxel.org/cgit/linux/commit/?h=bcm2837-wifi&id=36a2543dc4141904d6f22a9a35b738007967eab9

> Anyway I have it booting on the RPI 2 now, so I can debug.  I have
> noticed a very large number of experimental features being enabled in
> the config file.  I'm wondering if that could be contributing to this
> issue?

Possibly.  Suggestion on what to turn off and see if it has an effect?

Building 4.10-rc4 with the fedora default config atm, to see if that
makes a difference ...

cheers,
  Gerd