[PATCH] [v2] mt76: mt7915: fix unused 'mode' variable

[PATCH] [v2] mt76: mt7915: fix unused 'mode' variable

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

clang points out a possible corner case in the mt7915_tm_set_tx_cont()
function if called with invalid arguments:

drivers/net/wireless/mediatek/mt76/mt7915/testmode.c:593:2: warning: variable 'mode' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized]
        default:
        ^~~~~~~
drivers/net/wireless/mediatek/mt76/mt7915/testmode.c:597:13: note: uninitialized use occurs here
        rateval =  mode << 6 | rate_idx;
                   ^~~~
drivers/net/wireless/mediatek/mt76/mt7915/testmode.c:506:37: note: initialize the variable 'mode' to silence this warning
        u8 rate_idx = td->tx_rate_idx, mode;
                                           ^

Change it to return an error instead of continuing with invalid data
here.

Fixes: 3f0caa3cbf94 ("mt76: mt7915: add support for continuous tx in testmode")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
v2: remove the extra 'break;' after return.
---
 drivers/net/wireless/mediatek/mt76/mt7915/testmode.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/testmode.c b/drivers/net/wireless/mediatek/mt76/mt7915/testmode.c
index 7fb2170a9561..bd798df748ba 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/testmode.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/testmode.c
@@ -543,7 +543,7 @@ mt7915_tm_set_tx_cont(struct mt7915_phy *phy, bool en)
 		tx_cont->bw = CMD_CBW_20MHZ;
 		break;
 	default:
-		break;
+		return -EINVAL;
 	}
 
 	if (!en) {
@@ -591,7 +591,7 @@ mt7915_tm_set_tx_cont(struct mt7915_phy *phy, bool en)
 		mode = MT_PHY_TYPE_HE_MU;
 		break;
 	default:
-		break;
+		return -EINVAL;
 	}
 
 	rateval =  mode << 6 | rate_idx;
-- 
2.29.2

Re: [PATCH] [v2] mt76: mt7915: fix unused 'mode' variable

[Kalle Valo]

+ linux-wireless

Arnd Bergmann <arnd@kernel.org> writes:

> From: Arnd Bergmann <arnd@arndb.de>
>
> clang points out a possible corner case in the mt7915_tm_set_tx_cont()
> function if called with invalid arguments:
>
> drivers/net/wireless/mediatek/mt76/mt7915/testmode.c:593:2: warning: variable 'mode' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized]
>         default:
>         ^~~~~~~
> drivers/net/wireless/mediatek/mt76/mt7915/testmode.c:597:13: note: uninitialized use occurs here
>         rateval =  mode << 6 | rate_idx;
>                    ^~~~
> drivers/net/wireless/mediatek/mt76/mt7915/testmode.c:506:37: note: initialize the variable 'mode' to silence this warning
>         u8 rate_idx = td->tx_rate_idx, mode;
>                                            ^
>
> Change it to return an error instead of continuing with invalid data
> here.
>
> Fixes: 3f0caa3cbf94 ("mt76: mt7915: add support for continuous tx in testmode")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> v2: remove the extra 'break;' after return.
> ---
>  drivers/net/wireless/mediatek/mt76/mt7915/testmode.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

You forgot to Cc linux-wireless and hence patchwork didn't see this, so
I applied this manually instead:

c490492f15f6 mt76: mt7915: fix unused 'mode' variable

-- 
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches