Subject: [PATCH 6/8] arm: mach-armada: add support for Armada XP board with device tree

From: [email-masked] (Ben Dooks)
Date: Tue, 15 May 2012 16:07:59 +0100

On 15/05/12 15:58, Thomas Petazzoni wrote:
> Le Tue, 15 May 2012 15:32:36 +0100,
> Ben Dooks<[email-masked]>  a ?crit :
>
>> Yes, the number of times I've viewed the kernel and seen very similar
>> code replicated multiple times tends to make me burst into tears.
>>
>>>    * Maybe those mappings can be done using a normal ioremap() rather
>>>      than in ->map_io(), according to DT informations (but most
>>> other ARM SoC support at the moment seem to do PCI mappings using
>>> static mappings in ->map_io)
>>
>> That's a very old way of doing it. I'm pretty sure there's no reason
>> to get these allocated so early.
>>
>> I believe you can probably leave the PCI/PCIe bindings until you have
>> enough kernel state to do ioremap() or similar and then associate the
>> necessary mappings with the bus creation.
>
> Agreed. When looking at the code, I wasn't sure why PCI mappings were
> needed so early. Surely, the minimal mappings to get an UART are quite
> useful to have very early, but why PCI?

I think it was because that PCI was initialised early and requires a
large mapping space. It is very likely to be legacy kernel stuff that
people have kept copying through.

-- 
Ben Dooks				http://www.codethink.co.uk/
Senior Engineer				Codethink - Providing Genius