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

[Simon Glass]

Hi Stephen,

On 13 July 2015 at 22:52, Stephen Warren <swarren at wwwdotorg.org> 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.
>
> b) Build a different U-Boot + DTB image for each board-rev, and put the
> correct one on the SD card.
>
> Neither of those options seem like a good idea to me.

How about:

c) Leave the code as is, and not add a whole lot more device tree files.

After all the kernel only has files for rpi and rpi_2. Why should we
add one for each variant? If you don't want to do it, why do it?

Regards,
Simon