Re: [PATCH] Add a global ide=off switch for drivers/ide

[Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>]

On Friday 26 October 2007, Andi Kleen wrote:
> On Thursday 25 October 2007 23:07:23 Bartlomiej Zolnierkiewicz wrote:
> 
> > On Monday 15 October 2007, Andi Kleen wrote:
> > > 
> > > Had a situation where drivers/ide was compiled in, but I wanted to turn 
> > > it off to let the drivers/ata drivers take over. I ended up using ide*=noprobe,
> > > but that was somewhat clumpsy because I wasn't sure how many IDE interfaces
> > > the machine really had.
> > > 
> > > Add a global ide=off switch to handle this situation better.
> > 
> > Overall looks OK but I think we should limit it to IDE built-in case
> > (when IDE is modular it is all up to the user-space anyway).
> 
> Disagree. It's useful for the modular case too e.g. if you
> have the ide modules in your initrd and you want to not load
> them for some reason (e.g. debugging) 

This argument sounds rather weak, you may want to not load any other
modules from your inird and you don't add "module=off" to them. :)

Besides the patch in the current form is buggy for the modular IDE
since __ide_pci_register_driver() is valid only when IDE is built-in
(please see how ide_pci_register_driver() is defined in ide.h) and
the patch depends on it to handle "ide=off" for IDE PCI host drivers.

[ No hard feelings wrt modular IDE support if the above issue gets fixed. ]

> > This way we don't pollute device/host drivers with CONFIG_BLK_DEV_IDE #ifdefs.
> 
> What CONFIG_BLK_DEV_IDE ifdefs? I added the check only to code that is already
> conditional to this I believe and there were no additional ifdefs at all.

I meant the case if we made "ide=off" valid only for built-in IDE
(then simply referencing ide_off in device/host drivers is incorrect
since ide_off is covered by CONFIG_BLK_DEV_IDE #ifdef/#endif).

Thanks,
Bart