Re: devres and requesting resources

From: Bartlomiej Zolnierkiewicz
Date: Fri Feb 29 2008 - 11:50:31 EST


On Friday 29 February 2008, Alan Cox wrote:
> > controller like ICH AHCIs. ata_generic or ide generic might attach to a
> > controller which is already being driven by ahci under certain
> > configurations.
>
> ata_generic will not nor ata_legacy both are much too smart for that. The
> legacy old IDE driver might but that probably isn't going to be fixed by
> devres and is trivial to fix in that driver (just steal the code from
> pata_legacy).

Yep, nice trick.

Since it is your idea/code could you please also fix ide_generic? :)

> > have different requirements can just open code pci_request_regions() and
> > pcim_iomap(). pcim_request_regions() should provide sensible default
> > behavior for common cases.
>
> Which is arguably the current behaviour. Changing the behaviour and not
> the name is a really bad idea and will cause problems in future so don't
> do that.
> >
> > I think the best solution is to allow duplicate request regions for
> > managed devices which is okay as we know we're holding the resource and
> > let drivers which need to reserve all regions call pci_request_regions()
> > before calling pcim_request_regions().

This will work until code outside libata (i.e. IDE) starts using devres...

[ Incidentally, just yesterday I finished moving resource management handling
to host drivers so it might as well happen. ]

> How about
>
> pcim_request_all_regions()
>
> for the behaviour Jeff wants, simple, direct, differently named and
> obvious what it does.

Seconded.

Thanks,
Bart
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