diff mbox

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

Message ID 1350816727-1381-3-git-send-email-Julia.Lawall@lip6.fr (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Julia Lawall Oct. 21, 2012, 10:52 a.m. UTC 
From: Julia Lawall <Julia.Lawall@lip6.fr>

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@lip6.fr>

---
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(-)


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Comments

Luciano Coelho Nov. 16, 2012, 6:18 p.m. UTC | #1 
On Sun, 2012-10-21 at 12:52 +0200, Julia Lawall wrote:
> From: Julia Lawall <Julia.Lawall@lip6.fr>
> 
> 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.

[...]

Applied and pushed, thanks!

--
Luca.

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diff mbox

Patch

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)