Re: pci_get_device_reverse(), why does Calgary need this?

From: Greg KH
Date: Wed Feb 13 2008 - 18:44:16 EST


On Wed, Feb 13, 2008 at 11:20:36PM +0100, Bartlomiej Zolnierkiewicz wrote:
> On Wednesday 13 February 2008, Greg KH wrote:
> > On Wed, Feb 13, 2008 at 09:28:24AM -0800, Greg KH wrote:
> > > On Wed, Feb 13, 2008 at 01:34:12PM +0100, Bartlomiej Zolnierkiewicz wrote:
> > > > On Wednesday 13 February 2008, Greg KH wrote:
> > > > > On Wed, Feb 13, 2008 at 02:17:37AM +0000, Alan Cox wrote:
> > > > > > > Why does the calgary driver need this? Can we just use pci_get_device()
> > > > > > > instead? Why do you need to walk the device list backwards? Do you get
> > > > > > > false positives going forward?
> > > > > >
> > > > > > It doesn't look to be performance critical so the driver can
> > > > > > pci_get_device until the end and use the final hit anyway.
> > > > >
> > > > > That would make more sense.
> > > > >
> > > > > > IDE reverse is more problematic but nobody seems to use it.
> > > > >
> > > > > I've seen two posters say they use it. I'm wondering what it is really
> > > > > solving if they use it, and why if it's really needed, scsi never had to
> > > > > implement such a hack...
> > > >
> > > > It is no longer solving anything, just adds more pain. ;)
> > > >
> > > > [ The option comes from 2.2.x (so long before LABEL=/ and /dev/disk/by-id/
> > > > became popular). Some "off-board" controllers integrated on motherboards
> > > > used to appear before "on-board" IDE on PCI bus so this option was meant
> > > > to preserve the legacy ordering. ]
> > > >
> > > > Since it is valid only when "Probe IDE PCI devices in the PCI bus order
> > > > (DEPRECATED)" config option is used it is already on its way out (though
> > > > marking it as obsoleted would make it more explicit).
> > > >
> > > > I think that removing "ide=reverse" in 2.6.26 would be OK...
> > >
> > > Great, thanks for your blessing. I'll make up a patch and send it to
> > > you for approval.
> >
> > How does the patch below look? I didn't want to remove the whole config
> > option, as there is more to the logic than just the "reverse order"
> > stuff there.
>
> looks fine,
>
> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx>

Thanks.

> > If you don't mind, can I take this through the PCI tree so as to allow
> > the removal of this pci function afterwards?
>
> [...]
>
> great, could you also:
> - rebase it on top of the patch below
> - forward the patch below to Linus for 2.6.25

Sure, you want this to go in for .25, but not the one I just posted
removing this option, correct? That should wait for .26?

thanks,

greg k-h
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