Re: [PATCH] Fix checking for multiple boot tags in board config.

[Jonathan McDowell <noodles@earth.li>]

On Fri, Apr 07, 2006 at 06:50:15PM +0300, Imre Deak wrote:
> On Fri, 2006-04-07 at 16:00 +0100, ext Jonathan McDowell wrote:
> > Currently if we look for more than one instance of a boot tag and it's
> > defined in the board config rather than passed by the boot loader we can
> > get stuck in a loop where the same tag is processed many times. This can
> > be seen with the gpio-switch driver, for example. The patch below fixes
> > this by respecting the skip parameter to get_config when we're scanning
> > the board config structure.
> > 
> > Signed-Off-By: Jonathan McDowell <noodles@earth.li>
> > 
> > diff --git a/arch/arm/plat-omap/common.c b/arch/arm/plat-omap/common.c
> > index 0625df5..39ab667 100644
> > --- a/arch/arm/plat-omap/common.c
> > +++ b/arch/arm/plat-omap/common.c
> > @@ -114,8 +114,12 @@ static const void *get_config(u16 tag, s
> >  	 * in the kernel. */
> >  	for (i = 0; i < omap_board_config_size; i++) {
> >  		if (omap_board_config[i].tag == tag) {
> > -			kinfo = &omap_board_config[i];
> > -			break;
> > +			if (skip == 0) {
> > +				kinfo = &omap_board_config[i];
> > +				break;
> > +			} else {
> > +				skip--;
> > +			}
> >  		}
> >  	}
> >  	if (kinfo == NULL)
> 
> Should the case be handled when a configuration is present in both the
> boot tag and the board config? If so, we should stop parsing after the
> boot tags whenever the requested tag is found, even if there are less
> then 'skip' instances of it, and return NULL.

If a config option that can appear multiple times (ie when the skip
option would apply) is present in both the boot tag and board config I'd
expect both to have effect. You might have some instances of a device
that exist on all variants of the board (that would be in the board
config) and then some additional instances that would be controlled by
the boot tags passed by the boot loader. Though equally I can see the
argument for the other way when you'd want to override the defaults. :)

J.

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