[RBP] A collection of pending RPi fixes

[MilhouseVH]

The mailbox and overlays commits will be required by the latest RPi kernel (whenever you merge this).

[popcornmix]

Thanks @MilhouseVH
Changes look fine (but wait for next kernel bump before merging).

[sraue]

@popcornmix can you inform me per email if you committed the last kernel update patches please? thanks much

[popcornmix]

Rpi kernel drivers are gradually being accepted upstream. The upstream versions are generally rewritten, but based on downstream commits. They often have 2835 in the name rather than 2708.

We are slowly switching to upstream drivers where they have equivalent functionality. This often needs a change to .config options (e.g. enabling the 2835 version of the driver).

We are also moving some of the non-currently-upstreamed drivers out of the mach-bcm2708 directory into the correct driver place in the kernel tree and adding the ability to load them through device tree. This allows the downstream drivers to be used with the upstream mach-bcm2835 kernel.

The eventual goal is to make downstream mach-bcm2708 and upstream mach-bcm2835 kernels become as close as possible. We can then switch to using the mach-bcm2835 kernel with a much smaller number of patches.

We are doing this in a number of small steps to reduce the risk. The general plan is I ping @Milhouse about any build changes. He adds it to the next nightly build, and assuming no complaints he'll submit a PR a couple of days later.

I can include @sraue in the ping of any changes if it's useful for you to know what's going on. Or if you ping me/@Milhouse before bumping the kernel, we can let you know if there's any outstanding build changes required.

[sraue]

added in
277700a
0565d4a
2195fbb
ac55591
many thanks!