[PATCH 04/30] staging/vme: allow non-dynamic allocation of bus numbers

Martyn Welch martyn.welch at ge.com
Fri Nov 5 16:29:24 UTC 2010

On 04/11/10 03:40, Emilio G. Cota wrote:
> On Wed, Oct 27, 2010 at 11:13:27 -0400, Emilio G. Cota wrote:
>> On Wed, Oct 27, 2010 at 10:41:18 +0100, Martyn Welch wrote:
>>> On 26/10/10 02:10, Emilio G. Cota wrote:
>>>> From: Emilio G. Cota <cota at braap.org>
>>>> In a configuration with several bridges, each bridge is
>>>> assigned a certain bus number depending on the order in which
>>>> vme_register_bridge is called. This can complicate multi-bridge
>>>> installations because the eventual bus numbers will depend
>>>> on the order the bridges were loaded.
>>>> The appended allows bridges to register with a bus number of
>>>> their choice, while keeping the previous 'first come, first
>>>> served' behaviour as the default.
>>> I can't see where this is being used.
>> Each driver's .probe is fed with bus_number and slot_number.
>> Normally the driver will check that pair against what it received
>> through modparams and act accordingly.
>> For this to be reliable bus numbering should be consistent on
>> a given system, i.e. it should be possible to always allocate
>> the same bus number to a given bus. Otherwise, depending on
>> which bridge is installed first, we'd get different bus numbers
>> assigned.
>> Does that make it clearer now?
>>> I assume this is a part of future changes you wish to make?
>> AFAICT it affects the current model.
> Martyn,
> Have you had time to re-check this one?

I'm afraid I haven't - I'm rather tied up at the moment. I'll try and
set aside some time next week to look at the remaining patches you sent.


Martyn Welch (Principal Software Engineer)   |   Registered in England and
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