[PATCH 2/5] drivers/net/wireless/ti/wlcore/main.c: eliminate possible double power off

From: Julia Lawall
Date: Sun Oct 21 2012 - 06:52:57 EST


From: Julia Lawall <Julia.Lawall@xxxxxxx>

The function wl12xx_set_power_on is only called twice, once in
wl12xx_chip_wakeup and once in wl12xx_get_hw_info. On the failure of the
call in wl12xx_chip_wakeup, the containing function just returns, but on
the failure of the call in wl12xx_get_hw_info, the containing function
calls wl1271_power_off. This does not seem necessary, because if
wl12xx_set_power_on has set the power on and then fails, it has already
turned the power off.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@r@
identifier f,free,a;
parameter list[n] ps;
type T;
expression e;
@@

f(ps,T a,...) {
... when any
when != a = e
if(...) { ... free(a); ... return ...; }
... when any
}

@@
identifier r.f,r.free;
expression x,a;
expression list[r.n] xs;
@@

* x = f(xs,a,...);
if (...) { ... free(a); ... return ...; }
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxx>

---
wl1271_power_off seems to be resistent to being called when the power is
not on, so this should not change the behavior. Not tested.

drivers/net/wireless/ti/wlcore/main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ti/wlcore/main.c b/drivers/net/wireless/ti/wlcore/main.c
index 25530c8..0eb739b 100644
--- a/drivers/net/wireless/ti/wlcore/main.c
+++ b/drivers/net/wireless/ti/wlcore/main.c
@@ -5116,7 +5116,7 @@ static int wl12xx_get_hw_info(struct wl1271 *wl)

ret = wl12xx_set_power_on(wl);
if (ret < 0)
- goto out;
+ return ret;

ret = wlcore_read_reg(wl, REG_CHIP_ID_B, &wl->chip.id);
if (ret < 0)

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