Subject: [PATCH AUTOSEL 4.19 001/100] wil6210: fix freeing of rx buffers in EDMA mode

From: Sasha Levin <[email-masked]>
Date: Fri, 18 Oct 2019 18:03:46 -0400

From: Ahmad Masri <[email-masked]>

[ Upstream commit 6470f31927b46846d957628b719dcfda05446664 ]

After being associated with some EDMA rx traffic, upon "down" driver
doesn't free all skbs in the rx ring.
Modify wil_move_all_rx_buff_to_free_list to loop on active list of rx
buffers, unmap the physical memory and free the skb.

Signed-off-by: Ahmad Masri <[email-masked]>
Signed-off-by: Maya Erez <[email-masked]>
Signed-off-by: Kalle Valo <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 drivers/net/wireless/ath/wil6210/txrx_edma.c | 44 +++++++-------------
 1 file changed, 14 insertions(+), 30 deletions(-)

diff --git a/drivers/net/wireless/ath/wil6210/txrx_edma.c b/drivers/net/wireless/ath/wil6210/txrx_edma.c
index 3e7fc2983cbb3..409a6fa8b6c8f 100644
--- a/drivers/net/wireless/ath/wil6210/txrx_edma.c
+++ b/drivers/net/wireless/ath/wil6210/txrx_edma.c
@@ -234,9 +234,10 @@ static int wil_rx_refill_edma(struct wil6210_priv *wil)
 	struct wil_ring *ring = &wil->ring_rx;
 	u32 next_head;
 	int rc = 0;
-	u32 swtail = *ring->edma_rx_swtail.va;
+	ring->swtail = *ring->edma_rx_swtail.va;
 
-	for (; next_head = wil_ring_next_head(ring), (next_head != swtail);
+	for (; next_head = wil_ring_next_head(ring),
+	     (next_head != ring->swtail);
 	     ring->swhead = next_head) {
 		rc = wil_ring_alloc_skb_edma(wil, ring, ring->swhead);
 		if (unlikely(rc)) {
@@ -264,43 +265,26 @@ static void wil_move_all_rx_buff_to_free_list(struct wil6210_priv *wil,
 					      struct wil_ring *ring)
 {
 	struct device *dev = wil_to_dev(wil);
-	u32 next_tail;
-	u32 swhead = (ring->swhead + 1) % ring->size;
+	struct list_head *active = &wil->rx_buff_mgmt.active;
 	dma_addr_t pa;
-	u16 dmalen;
 
-	for (; next_tail = wil_ring_next_tail(ring), (next_tail != swhead);
-	     ring->swtail = next_tail) {
-		struct wil_rx_enhanced_desc dd, *d = &dd;
-		struct wil_rx_enhanced_desc *_d =
-			(struct wil_rx_enhanced_desc *)
-			&ring->va[ring->swtail].rx.enhanced;
-		struct sk_buff *skb;
-		u16 buff_id;
+	while (!list_empty(active)) {
+		struct wil_rx_buff *rx_buff =
+			list_first_entry(active, struct wil_rx_buff, list);
+		struct sk_buff *skb = rx_buff->skb;
 
-		*d = *_d;
-
-		/* Extract the SKB from the rx_buff management array */
-		buff_id = __le16_to_cpu(d->mac.buff_id);
-		if (buff_id >= wil->rx_buff_mgmt.size) {
-			wil_err(wil, "invalid buff_id %d\n", buff_id);
-			continue;
-		}
-		skb = wil->rx_buff_mgmt.buff_arr[buff_id].skb;
-		wil->rx_buff_mgmt.buff_arr[buff_id].skb = NULL;
 		if (unlikely(!skb)) {
-			wil_err(wil, "No Rx skb at buff_id %d\n", buff_id);
+			wil_err(wil, "No Rx skb at buff_id %d\n", rx_buff->id);
 		} else {
-			pa = wil_rx_desc_get_addr_edma(&d->dma);
-			dmalen = le16_to_cpu(d->dma.length);
-			dma_unmap_single(dev, pa, dmalen, DMA_FROM_DEVICE);
-
+			rx_buff->skb = NULL;
+			memcpy(&pa, skb->cb, sizeof(pa));
+			dma_unmap_single(dev, pa, wil->rx_buf_len,
+					 DMA_FROM_DEVICE);
 			kfree_skb(skb);
 		}
 
 		/* Move the buffer from the active to the free list */
-		list_move(&wil->rx_buff_mgmt.buff_arr[buff_id].list,
-			  &wil->rx_buff_mgmt.free);
+		list_move(&rx_buff->list, &wil->rx_buff_mgmt.free);
 	}
 }
 
-- 
2.20.1