[PATCH] ath11k: Remove unused variable in ath11k_dp_rx_mon_merg_msdus()

From: Tim Gardner
Date: Mon Sep 27 2021 - 11:08:08 EST

Coverity complains that a constant variable guards dead code. In fact,
mpdu_buf is set NULL and never updated.

null: At condition mpdu_buf, the value of mpdu_buf must be NULL.
dead_error_condition: The condition mpdu_buf cannot be true.
CID 92162 (#1 of 1): 'Constant' variable guards dead code (DEADCODE)
dead_error_line: Execution cannot reach the expression decap_format !=
DP_RX_DECAP_TYPE_RAW inside this statement: if (mpdu_buf && decap_forma....
Local variable mpdu_buf is assigned only once, to a constant value, making it
effectively constant throughout its scope. If this is not the intent, examine
the logic to see if there is a missing assignment that would make mpdu_buf not
remain constant.
4835 if (mpdu_buf && decap_format != DP_RX_DECAP_TYPE_RAW) {

Fix this by removing mpdu_buf and unreachable code.

Cc: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: ath11k@xxxxxxxxxxxxxxxxxxx
Cc: linux-wireless@xxxxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Signed-off-by: Tim Gardner <tim.gardner@xxxxxxxxxxxxx>
drivers/net/wireless/ath/ath11k/dp_rx.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/dp_rx.c b/drivers/net/wireless/ath/ath11k/dp_rx.c
index 9a224817630a..7d57952fd73c 100644
--- a/drivers/net/wireless/ath/ath11k/dp_rx.c
+++ b/drivers/net/wireless/ath/ath11k/dp_rx.c
@@ -4740,7 +4740,7 @@ ath11k_dp_rx_mon_merg_msdus(struct ath11k *ar,
struct ieee80211_rx_status *rxs)
struct ath11k_base *ab = ar->ab;
- struct sk_buff *msdu, *mpdu_buf, *prev_buf;
+ struct sk_buff *msdu, *prev_buf;
u32 wifi_hdr_len;
struct hal_rx_desc *rx_desc;
char *hdr_desc;
@@ -4748,8 +4748,6 @@ ath11k_dp_rx_mon_merg_msdus(struct ath11k *ar,
struct ieee80211_hdr_3addr *wh;
struct rx_attention *rx_attention;

- mpdu_buf = NULL;
if (!head_msdu)
goto err_merge_fail;

@@ -4832,12 +4830,6 @@ ath11k_dp_rx_mon_merg_msdus(struct ath11k *ar,
return head_msdu;

- if (mpdu_buf && decap_format != DP_RX_DECAP_TYPE_RAW) {
- ath11k_dbg(ab, ATH11K_DBG_DATA,
- "err_merge_fail mpdu_buf %pK", mpdu_buf);
- /* Free the head buffer */
- dev_kfree_skb_any(mpdu_buf);
- }
return NULL;