[U-Boot] [PATCH 00/20] arm: rpi: Enable USB and Ethernet driver model Raspberry Pi

[Simon Glass]

Hi Stephen,

On 16 July 2015 at 08:10, Pavel Machek <pavel at denx.de> wrote:
> On Mon 2015-07-13 22:52:58, Stephen Warren wrote:
>> On 07/11/2015 08:04 AM, Simon Glass wrote:
>> > Hi Stephen,
>> >
>> > On 10 July 2015 at 23:34, Stephen Warren <swarren at wwwdotorg.org> wrote:
>> >> On 07/07/2015 08:53 PM, Simon Glass wrote:
>> >>> Raspberry Pi uses a DWC2 USB controller and a SMSC USB Ethernet adaptor.
>> >>> Neither of these currently support driver model.
>> >>>
>> >>> This series does the following:
>> >>> - Move Raspberry Pi to use device tree control (u-boot-dtb.bin instead of
>> >>>      u-boot.bin)
>> >>
>> >> I'd strongly prefer not to do this. For one thing, it means we'd need
>> >> different U-Boot builds for each of the different RPi models, and we
>> >> currently don't need that (or perhaps we require users to create their
>> >> own u-boot-dtb.bin by choosing the right DTB to append). If it
>> >
>> > Why does device tree change how things work now? The get_board_rev()
>> > function currently deals with this. It doesn't look like rpi_board_rev
>> > is used anywhere else.
>>
>> Without a DT, the code is free to make all the board-rev-specific
>> decisions at run-time without external influence.
>>
>> With a DT, we either have to:
>>
>> a) Pick the DT for one particular board and use that everywhere, even if
>> it's incorrect for the actual board in use.
>
> Is that an option? I mean... if you can tolerate incorrect values for
> something, perhaps that something should not be in the dtb in the
> first place?
>
>> b) Build a different U-Boot + DTB image for each board-rev, and put the
>> correct one on the SD card.
>
> d) Build U-Boot + set of DTB images, then pick up the right one at the
> runtime?
>
>> Neither of those options seem like a good idea to me.
>
> Stuff that can be autodetected does not belong to the device tree...
>
>                                                                         Pavel
> --
> (english) http://www.livejournal.com/~pavelmachek
> (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Stephen please can you update here? It seems to me that there is no
requirement to add a lot of stuff to the device tree which we already
have code to auto-detect.

I'd like to pull in these changes but can hold off on the rpi parts
until we figure this out.

Regards,
Simon