Re: [PATCH v3 2/3] gianfar: Delete unnecessary variable initialisations in gfar_ethflow_to_filer_table()

From: Dan Carpenter
Date: Fri Jan 15 2016 - 07:15:58 EST


On Fri, Jan 15, 2016 at 12:34:33PM +0100, SF Markus Elfring wrote:
> >> +++ b/drivers/net/ethernet/freescale/gianfar_ethtool.c
> >> @@ -768,12 +768,12 @@ static void ethflow_to_filer_rules (struct gfar_private *priv, u64 ethflow)
> >> static int gfar_ethflow_to_filer_table(struct gfar_private *priv, u64 ethflow,
> >> u64 class)
> >> {
> >> - unsigned int last_rule_idx = priv->cur_filer_idx;
> >> + unsigned int last_rule_idx;
> >
> > This is a write only variable. We can just remove it.
>
> Can a static source code analysis tool like the software "http://smatch.sourceforge.net/";
> detect that such a variable is not read by this function implementation so far?

Yeah. That's a good idea. I will do that.

> https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/tree/drivers/net/ethernet/freescale/gianfar_ethtool.c?id=b75ec3af27bf011a760e2f44eb25a99b6fbb0fb3#n850
>
> Does this place indicate an unwanted value assignment as a leftover,
> or are there any other actions missing?

I think it's just an extra variable and you can just delete it.

regards,
dan carpenter