[PATCH v2] cw1200: fix bogus maybe-uninitialized warning

From: Arnd Bergmann
Date: Tue Oct 25 2016 - 16:21:53 EST


On x86, the cw1200 driver produces a rather silly warning about the
possible use of the 'ret' variable without an initialization
presumably after being confused by the architecture specific definition
of WARN_ON:

drivers/net/wireless/st/cw1200/wsm.c: In function âwsm_handle_rxâ:
drivers/net/wireless/st/cw1200/wsm.c:1457:9: error: âretâ may be used uninitialized in this function [-Werror=maybe-uninitialized]

We have already checked that 'count' is larger than 0 here, so
we know that 'ret' is initialized. Changing the 'for' loop
into do/while also makes this clear to the compiler.

Suggested-by: David Laight <David.Laight@xxxxxxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/net/wireless/st/cw1200/wsm.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)

v2: rewrite based on David Laight's suggestion, the first version
was completely wrong.

diff --git a/drivers/net/wireless/st/cw1200/wsm.c b/drivers/net/wireless/st/cw1200/wsm.c
index 680d60eabc75..ed93bf3474ec 100644
--- a/drivers/net/wireless/st/cw1200/wsm.c
+++ b/drivers/net/wireless/st/cw1200/wsm.c
@@ -379,7 +379,6 @@ static int wsm_multi_tx_confirm(struct cw1200_common *priv,
{
int ret;
int count;
- int i;

count = WSM_GET32(buf);
if (WARN_ON(count <= 0))
@@ -395,11 +394,10 @@ static int wsm_multi_tx_confirm(struct cw1200_common *priv,
}

cw1200_debug_txed_multi(priv, count);
- for (i = 0; i < count; ++i) {
+ do {
ret = wsm_tx_confirm(priv, buf, link_id);
- if (ret)
- return ret;
- }
+ } while (!ret && --count);
+
return ret;

underflow:
--
2.9.0