[PATCH ath-next 2/2] wifi: ath11k: don't take a monitor PPDU ID of 0 for no change

[Christopher Griffin via B4 Relay]

From: Christopher Griffin <christophergriffin05 at gmail.com>

ath11k_dp_rx_mon_comp_ppduid() returns the PPDU ID it moved *ppdu_id
to, and ath11k_dp_rx_mon_mpdu_pop() takes a return of 0 for "no
change". When the destination ring's PPDU ID wraps to 0, it moves
*ppdu_id to 0 and returns 0, so mpdu_pop goes on and chains the MPDU.
The caller, ath11k_dp_rx_mon_dest_process(), then sees its ppdu_id
changed and breaks out with that chain neither delivered nor freed.

On an IPQ8074 with a monitor interface on each radio this lost 37 MPDU
chains in 47 minutes (2.8 million MPDUs); with this change, none in 46
minutes at the same load (3.2 million).

Return whether the PPDU ID changed.

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.9.0.1-02146-QCAHKSWPL_SILICONZ-1

Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
Signed-off-by: Christopher Griffin <christophergriffin05 at gmail.com>
---
 drivers/net/wireless/ath/ath11k/dp_rx.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/dp_rx.c b/drivers/net/wireless/ath/ath11k/dp_rx.c
index f0bff6c16..64fc83ee5 100644
--- a/drivers/net/wireless/ath/ath11k/dp_rx.c
+++ b/drivers/net/wireless/ath/ath11k/dp_rx.c
@@ -4656,15 +4656,13 @@ static void ath11k_hal_rx_msdu_list_get(struct ath11k *ar,
 	*num_msdus = i;
 }
 
-static u32 ath11k_dp_rx_mon_comp_ppduid(u32 msdu_ppdu_id, u32 *ppdu_id,
-					u32 *rx_bufs_used)
+static bool ath11k_dp_rx_mon_comp_ppduid(u32 msdu_ppdu_id, u32 *ppdu_id,
+					 u32 *rx_bufs_used)
 {
-	u32 ret = 0;
-
 	if ((*ppdu_id < msdu_ppdu_id) &&
 	    ((msdu_ppdu_id - *ppdu_id) < DP_NOT_PPDU_ID_WRAP_AROUND)) {
 		*ppdu_id = msdu_ppdu_id;
-		ret = msdu_ppdu_id;
+		return true;
 	} else if ((*ppdu_id > msdu_ppdu_id) &&
 		((*ppdu_id - msdu_ppdu_id) > DP_NOT_PPDU_ID_WRAP_AROUND)) {
 		/* mon_dst is behind than mon_status
@@ -4672,9 +4670,9 @@ static u32 ath11k_dp_rx_mon_comp_ppduid(u32 msdu_ppdu_id, u32 *ppdu_id,
 		 */
 		*rx_bufs_used += 1;
 		*ppdu_id = msdu_ppdu_id;
-		ret = msdu_ppdu_id;
+		return true;
 	}
-	return ret;
+	return false;
 }
 
 static void ath11k_dp_mon_get_buf_len(struct hal_rx_msdu_desc_info *info,

-- 
2.43.0