Messages in this thread | | | From | Bret Indrelee <> | Subject | RE: resending patch: Documentation/pci.txt | Date | Wed, 17 Nov 1999 15:39:08 -0600 |
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Alan Cox [mailto:alan@lxorguk.ukuu.org.uk] wrote: > > Damn it! The name appears to have changed between 2.2 and 2.3. > > It did. That maybe good to note
Yeah, and also goes a long way towards explaining why my documentation changes never went anywhere.
They are wrong for 2.3, but mostly right for 2.2.
Shall I resubmit them as a patch to 2.2 documentation, taking out the stuff about check_/request_/release_*_region? Or am I still misunderstanding something in the 2.2 kernel?
> > 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
Actually, this isn't what I understood Martin to have told me. I had written him on this exact point to get clarification.
It is a 'converted BAR', not the value in the PCI BAR. It is the physical address on that system bus, although someone mentioned this should probably be treated more as a cookie in order to be architechure neutral.
In any case, on 2.2.x I was told that it was the value to pass into ioremap().
> 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.
Great. Sounds like someone should document this somewhere.
Going to make for a reasonable amount of ifdefs() in drivers that are used on both 2.2 and the development kernel. Yuck.
-Bret
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