[U-Boot] [PATCH] nand: Fix set_dev checks for no device

[Scott Wood <oss@buserror.net>]

On Tue, 2016-08-23 at 15:04 -0700, Tony Lindgren wrote:
> * Scott Wood <oss@buserror.net> [160823 14:31]:
> > 
> > On Tue, 2016-08-23 at 14:26 -0700, Tony Lindgren wrote:
> > > 
> > > If we do nand device 0 command in u-boot on a device that has NAND
> > > support
> > > enabled but no NAND chip, we can get data abort at least on omaps.
> > > 
> > > Fix the issue by adding a check for nand_info[dev].
> > > 
> > > Signed-off-by: Tony Lindgren <tony@atomide.com>
> > > --- a/cmd/nand.c
> > > +++ b/cmd/nand.c
> > > @@ -116,7 +116,7 @@ free_dat:
> > > ?static int set_dev(int dev)
> > > ?{
> > > ?	if (dev < 0 || dev >= CONFIG_SYS_MAX_NAND_DEVICE ||
> > > -	????!nand_info[dev]->name) {
> > > +	????!nand_info[dev] || !nand_info[dev]->name) {
> > > ?		puts("No such device\n");
> > > ?		return -1;
> > > ?	}
> > The new !nand_info[dev] check can replace the old name check (similarly to
> > how
> > commit?4cc9699be7ffc replaced the old zero-blocksize check).
> Do you mean we can now leave out the test for !nand_info[dev]->name
> in set_dev() with this patch?

Yes. ?It existed before because before the array-to-pointer conversion there
was no way to directly test nand_info[dev] for emptiness.

-Scott