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 ‘wsm_handle_rx’:
drivers/net/wireless/st/cw1200/wsm.c:1457:9: error: ‘ret’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
As the driver just checks the same variable twice here, we can simplify
it by removing the second condition, which makes it more readable and
avoids the warning.
Signed-off-by: Arnd Bergmann <[email protected]>
---
drivers/net/wireless/st/cw1200/wsm.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)
diff --git a/drivers/net/wireless/st/cw1200/wsm.c b/drivers/net/wireless/st/cw1200/wsm.c
index 680d60eabc75..094e6637ade2 100644
--- a/drivers/net/wireless/st/cw1200/wsm.c
+++ b/drivers/net/wireless/st/cw1200/wsm.c
@@ -385,14 +385,13 @@ static int wsm_multi_tx_confirm(struct cw1200_common *priv,
if (WARN_ON(count <= 0))
return -EINVAL;
- if (count > 1) {
- /* We already released one buffer, now for the rest */
- ret = wsm_release_tx_buffer(priv, count - 1);
- if (ret < 0)
- return ret;
- else if (ret > 0)
- cw1200_bh_wakeup(priv);
- }
+ /* We already released one buffer, now for the rest */
+ ret = wsm_release_tx_buffer(priv, count - 1);
+ if (ret < 0)
+ return ret;
+
+ if (ret > 0)
+ cw1200_bh_wakeup(priv);
cw1200_debug_txed_multi(priv, count);
for (i = 0; i < count; ++i) {
--
2.9.0
From: Of Arnd Bergmann
> Sent: 24 October 2016 16:42
> 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 wsm_handle_rx:
> drivers/net/wireless/st/cw1200/wsm.c:1457:9: error: ret may be used uninitialized in this function [-
> Werror=maybe-uninitialized]
>
> As the driver just checks the same variable twice here, we can simplify
> it by removing the second condition, which makes it more readable and
> avoids the warning.
>
> Signed-off-by: Arnd Bergmann <[email protected]>
> ---
> drivers/net/wireless/st/cw1200/wsm.c | 15 +++++++--------
> 1 file changed, 7 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/net/wireless/st/cw1200/wsm.c b/drivers/net/wireless/st/cw1200/wsm.c
> index 680d60eabc75..094e6637ade2 100644
> --- a/drivers/net/wireless/st/cw1200/wsm.c
> +++ b/drivers/net/wireless/st/cw1200/wsm.c
> @@ -385,14 +385,13 @@ static int wsm_multi_tx_confirm(struct cw1200_common *priv,
> if (WARN_ON(count <= 0))
> return -EINVAL;
>
> - if (count > 1) {
> - /* We already released one buffer, now for the rest */
> - ret = wsm_release_tx_buffer(priv, count - 1);
> - if (ret < 0)
> - return ret;
> - else if (ret > 0)
> - cw1200_bh_wakeup(priv);
> - }
> + /* We already released one buffer, now for the rest */
> + ret = wsm_release_tx_buffer(priv, count - 1);
> + if (ret < 0)
> + return ret;
> +
> + if (ret > 0)
> + cw1200_bh_wakeup(priv);
That doesn't look equivalent to me (when count == 1).
>
> cw1200_debug_txed_multi(priv, count);
> for (i = 0; i < count; ++i) {
Convert this loop into a do ... while so the body executes at least once.
David
On Tue, Oct 25, 2016 at 01:24:55PM +0000, David Laight wrote:
> > - if (count > 1) {
> > - /* We already released one buffer, now for the rest */
> > - ret = wsm_release_tx_buffer(priv, count - 1);
> > - if (ret < 0)
> > - return ret;
> > - else if (ret > 0)
> > - cw1200_bh_wakeup(priv);
> > - }
> > + /* We already released one buffer, now for the rest */
> > + ret = wsm_release_tx_buffer(priv, count - 1);
> > + if (ret < 0)
> > + return ret;
> > +
> > + if (ret > 0)
> > + cw1200_bh_wakeup(priv);
>
> That doesn't look equivalent to me (when count == 1).
I concur, this patch should not be applied in its current form.
- Solomon
--
Solomon Peachy pizza at shaftnet dot org
Delray Beach, FL ^^ (email/xmpp) ^^
Quidquid latine dictum sit, altum viditur.
On Tuesday, October 25, 2016 1:24:55 PM CEST David Laight wrote:
> > diff --git a/drivers/net/wireless/st/cw1200/wsm.c b/drivers/net/wireless/st/cw1200/wsm.c
> > index 680d60eabc75..094e6637ade2 100644
> > --- a/drivers/net/wireless/st/cw1200/wsm.c
> > +++ b/drivers/net/wireless/st/cw1200/wsm.c
> > @@ -385,14 +385,13 @@ static int wsm_multi_tx_confirm(struct cw1200_common *priv,
> > if (WARN_ON(count <= 0))
> > return -EINVAL;
> >
> > - if (count > 1) {
> > - /* We already released one buffer, now for the rest */
> > - ret = wsm_release_tx_buffer(priv, count - 1);
> > - if (ret < 0)
> > - return ret;
> > - else if (ret > 0)
> > - cw1200_bh_wakeup(priv);
> > - }
> > + /* We already released one buffer, now for the rest */
> > + ret = wsm_release_tx_buffer(priv, count - 1);
> > + if (ret < 0)
> > + return ret;
> > +
> > + if (ret > 0)
> > + cw1200_bh_wakeup(priv);
>
> That doesn't look equivalent to me (when count == 1).
Ah, that's what I missed, thanks for pointing that out!
> >
> > cw1200_debug_txed_multi(priv, count);
> > for (i = 0; i < count; ++i) {
>
> Convert this loop into a do ... while so the body executes at least once.
Good idea. Version 2 coming now.
Arnd