Re: resending patch: Documentation/pci.txt

Alan Cox (alan@lxorguk.ukuu.org.uk)
Wed, 17 Nov 1999 21:19:09 +0000 (GMT)


> Damn it! The name appears to have changed between 2.2 and 2.3.

It did. That maybe good to note

> In pci.h the struct in 2.2.13 (and I would assume later) had
>
> unsigned long base_address[6]
>
> which cooresponded to the various PCI Base Address Registers.
>
> Why did this change, and what was wrong with the old base_address[] array?
> Since every PCI driver is supposed to get the address from this field, I
> think this is a legitimate question.

2.2.x you get the value from the PCI registers. Its a copy of the BAR with flags
With 2.3.x you get told the start/end/size of each resource and if it is
I/O or memory. Resource objects are portable for all busses. Also they do the
things like 64bit using dual BAR's properly for you, and they can do magic
mappings as needed.

Alan

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