RE: [PATCH 2/3 v4] P4080/mtd: Only make elbc nand driver detect nand flash partitions

-----Original Message-----
From: Wood Scott-B07421
Sent: Monday, October 04, 2010 23:38 PM
To: Zang Roy-R61911
Cc: Anton Vorontsov; linux-mtd@lists.infradead.org;

dwmw2@infradead.org;

dedekind1@gmail.com; akpm@linux-foundation.org; Lan Chunhe-B25806;

Wood Scott-

B07421; Gala Kumar-B11780; linuxppc-dev@ozlabs.org
Subject: Re: [PATCH 2/3 v4] P4080/mtd: Only make elbc nand driver

detect nand

flash partitions
=20
On Sat, 2 Oct 2010 05:36:27 -0700
"Zang Roy-R61911" [off-list ref] wrote:
=20

quoted

quoted

-----Original Message-----
From: Anton Vorontsov [mailto:cbouatmailru@gmail.com]
Sent: Monday, September 20, 2010 21:19 PM
To: Zang Roy-R61911
Cc: linux-mtd@lists.infradead.org; dwmw2@infradead.org;

dedekind1@gmail.com;

quoted

quoted

akpm@linux-foundation.org; Lan Chunhe-B25806; Wood Scott-B07421;

Gala

Kumar-

quoted

quoted

B11780; linuxppc-dev@ozlabs.org
Subject: Re: [PATCH 2/3 v4] P4080/mtd: Only make elbc nand driver

detect

nand

quoted

quoted

flash partitions

On Fri, Sep 17, 2010 at 03:01:08PM +0800, Roy Zang wrote:
[...]

quoted

+static struct mutex fsl_elbc_nand_mutex;
+
+static int __devinit fsl_elbc_nand_probe(struct platform_device

*dev)

quoted

quoted

quoted

 {
-	struct fsl_lbc_regs __iomem *lbc =3D ctrl->regs;
+	struct fsl_lbc_regs __iomem *lbc;
 	struct fsl_elbc_mtd *priv;
 	struct resource res;
+	struct fsl_elbc_fcm_ctrl *elbc_fcm_ctrl =3D NULL;

No need for =3D NULL.

Any harm? Or just personal habit or style? Can you explain about

why?

=20
Besides not wanting superfluous code on general principle, it could
hide a bug if in the future the real initialization is missing on some
code path.  It would become a runtime NULL dereference rather than a
compiler warning.

Not exactly.
Per my understand, if the pointer will definitely be assigned in code
path,
it is not necessary to init it when define. for example,

char c;
char b;
char *a;
if (condition)
	a =3D &c;
else
	a =3D &b;
...

for other case, if the path will not ensure the pointer assignment, it
will be inited
when define to avoid warning. for example,

char c;
char *a =3D NULL;
if (condition)
	a =3D &c;
...

Thanks.
Roy