[coreboot] are the pci devices scanned two rounds?

王思源 wangsiyuanbuaa at gmail.com
Thu Sep 27 00:33:14 CEST 2012


thank you! Marc
what is the scheme of of the pci scanning?
when a new pci device is detected, all the pci device are re-scanned?
for example,bridge 00:14.4 is scanned two times. there is a vga device
connected to this bridge and the vga is allocted different bus number
in the scanning. so I don't think it is resonable.

Thank youi!

On Thu, Sep 27, 2012 at 1:15 AM, Marc Jones <marcj303 at gmail.com> wrote:
> On Wed, Sep 26, 2012 at 4:14 AM, 王思源 <wangsiyuanbuaa at gmail.com> wrote:
>> it seems that the pci devices are scanned two rounds in our mainboard.
>> first round: bus 0 -> bridge 00:14.4 -> bus 1 (this is the vga device
>> under the bridge 00:14.4)
>> second round: bus 0 -> bridge 00:02.0 -> bridge 00:04.0 -> bridge
>> 00:05.0. this bridges are all pcie bridges.
>>
>> I want to know whether the two rounds scanning style is right. if it
>> is designed to scan two rounds, why?
>> any reply is helpful to me.
>> thank you!
>>
> Yes, there are multiple steps in device tress and pci resource
> discovery and allocation.
>
>> WANG Siyuan
>>
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>> coreboot mailing list: coreboot at coreboot.org
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>
>
>
> --
> http://se-eng.com



-- 
王思源




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