Musings on PCI busses

Grant Likely grant.likely at secretlab.ca
Wed May 20 06:02:55 EST 2009


On Tue, May 19, 2009 at 1:05 PM, David Miller <davem at davemloft.net> wrote:
> From: Arnd Bergmann <arnd at arndb.de>
> Date: Tue, 19 May 2009 18:12:02 +0200
>
>> On Tuesday 19 May 2009, Grant Likely wrote:
>>> 1) Probe the host controller in an of_platform driver.  This has the
>>> advantage of simplicity.  The probe routine will get automatically
>>> called when the PCI host controller device tree node is registered
>>> with the of_platform bus.  The bus parenthood also gets reflected in
>>> the device model and sysfs.  The disadvantage is that it defers PCI
>>> bus probing until after the of_platform bus is probed (maybe this is
>>> okay; maybe this already happens anyway).
>>
>> This is also what we do on 64-bit systems (well, Cell at this time).
>> There are no fundamental problems with this, just some slightly
>> unexpected interactions e.g. when you have use a PCI serial port
>> as your console before probing PCI.
>
> This is also what sparc64 does :-)
>
> All of the individual sparc64 PCI controller types have a OF driver
> and then there is a common layer of OF PCI helper code to do most
> of the work.

Cool, well I have my solution then.  :-)

g.


-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.



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