[PATCH] iwlwifi: work around clang -Wuninitialized warning

From: Arnd Bergmann
Date: Fri Mar 22 2019 - 10:13:43 EST


Clang incorrectly warns about an uninitialized variable:

drivers/net/wireless/intel/iwlwifi/mvm/sta.c:2114:12: error: variable 'queue' is used uninitialized whenever 'if'
condition is false [-Werror,-Wsometimes-uninitialized]
else if (WARN(1, "Missing required TXQ for adding bcast STA\n"))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/asm-generic/bug.h:130:36: note: expanded from macro 'WARN'
#define WARN(condition, format...) ({ \
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/wireless/intel/iwlwifi/mvm/sta.c:2119:33: note: uninitialized use occurs here
iwl_mvm_enable_txq(mvm, NULL, queue, 0, &cfg, wdg_timeout);
^~~~~
drivers/net/wireless/intel/iwlwifi/mvm/sta.c:2114:8: note: remove the 'if' if its condition is always true
else if (WARN(1, "Missing required TXQ for adding bcast STA\n"))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/wireless/intel/iwlwifi/mvm/sta.c:2094:11: note: initialize the variable 'queue' to silence this warning
int queue;
^
= 0
1 error generated.

This cannot happen because the if/else if/else if block always
has one code path that is entered. However, we can simply
rearrange the code to let clang see this as well.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/net/wireless/intel/iwlwifi/mvm/sta.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
index 498c315291cf..91ce56d2ebb8 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
@@ -2107,12 +2107,14 @@ int iwl_mvm_send_add_bcast_sta(struct iwl_mvm *mvm, struct ieee80211_vif *vif)

if (!iwl_mvm_has_new_tx_api(mvm)) {
if (vif->type == NL80211_IFTYPE_AP ||
- vif->type == NL80211_IFTYPE_ADHOC)
+ vif->type == NL80211_IFTYPE_ADHOC) {
queue = mvm->probe_queue;
- else if (vif->type == NL80211_IFTYPE_P2P_DEVICE)
+ } else if (vif->type == NL80211_IFTYPE_P2P_DEVICE) {
queue = mvm->p2p_dev_queue;
- else if (WARN(1, "Missing required TXQ for adding bcast STA\n"))
+ } else {
+ WARN(1, "Missing required TXQ for adding bcast STA\n");
return -EINVAL;
+ }

bsta->tfd_queue_msk |= BIT(queue);

--
2.20.0