2009-12-19 07:30:35

by Julia Lawall

Subject: [PATCH 2/2] drivers/dma: drop unnecesary memset

From: Julia Lawall <[email protected]>

memset of 0 is not needed after kzalloc

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression x;
statement S;
@@

x = kzalloc(...);
if (x == NULL) S
... when != x
-memset(x,0,...);// </smpl>

Signed-off-by: Julia Lawall <[email protected]>

---
drivers/dma/dw_dmac.c | 2 --
1 file changed, 2 deletions(-)

diff -u -p a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -1270,8 +1270,6 @@ static int __init dw_probe(struct platfo
goto err_kfree;
}

- memset(dw, 0, sizeof *dw);
-
dw->regs = ioremap(io->start, DW_REGLEN);
if (!dw->regs) {
err = -ENOMEM;

2009-12-23 15:08:14

by Sosnowski, Maciej

Subject: RE: [PATCH 2/2] drivers/dma: drop unnecesary memset

Julia Lawall wrote:
> From: Julia Lawall <[email protected]>
>
> memset of 0 is not needed after kzalloc
>
> The semantic patch that makes this change is as follows:
> (http://coccinelle.lip6.fr/)
>
> // <smpl>
> @@
> expression x;
> statement S;
> @@
>
> x = kzalloc(...);
> if (x == NULL) S
> ... when != x
> -memset(x,0,...);// </smpl>
>
> Signed-off-by: Julia Lawall <[email protected]>
>
> ---
> drivers/dma/dw_dmac.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff -u -p a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
> --- a/drivers/dma/dw_dmac.c
> +++ b/drivers/dma/dw_dmac.c
> @@ -1270,8 +1270,6 @@ static int __init dw_probe(struct platfo
> goto err_kfree;
> }
>
> - memset(dw, 0, sizeof *dw);
> -
> dw->regs = ioremap(io->start, DW_REGLEN);
> if (!dw->regs) {
> err = -ENOMEM;

Acked-by: Maciej Sosnowski <[email protected]>-