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

[Tony Lindgren]

* Scott Wood <oss at buserror.net> [160823 15:08]:
> On Tue, 2016-08-23 at 15:04 -0700, Tony Lindgren wrote:
> > * Scott Wood <oss at 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 at 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.

OK seems to work. Updated patch below.

Regards,

Tony
8< -----------------
From: Tony Lindgren <tony at atomide.com>
Date: Tue, 23 Aug 2016 15:14:26 -0700
Subject: [PATCHv2] nand: Fix set_dev checks for no device

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 replaceing the check with nand_info[dev] as
suggested by Scott Wood. The check for name existed before because before
the array-to-pointer conversion there was no way to directly test
nand_info[dev] for emptiness.

Signed-off-by: Tony Lindgren <tony at atomide.com>

--- a/cmd/nand.c
+++ b/cmd/nand.c
@@ -115,8 +115,7 @@ free_dat:
 
 static int set_dev(int dev)
 {
-	if (dev < 0 || dev >= CONFIG_SYS_MAX_NAND_DEVICE ||
-	    !nand_info[dev]->name) {
+	if (dev < 0 || dev >= CONFIG_SYS_MAX_NAND_DEVICE || !nand_info[dev]) {
 		puts("No such device\n");
 		return -1;
 	}