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

[Pavel Machek]

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
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