ath10k: prevent endless pci rx loop

It was possible to enter an endless loop while
processing a single pci copy engine pipe. This
could effectively render ath10k incapable of
responding to any requests.

An example case when this could happen is when
firmware generates a lot of events, e.g. spectral
scan phyerr via WMI.

Reported-by: Janusz Dziedzic <janusz.dziedzic@tieto.com>
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

1 files changed, 9 insertions, 8 deletions

diff --git a/drivers/net/wireless/ath/ath10k/pci.c b/drivers/net/wireless/ath/ath10k/pci.c
index 06840d101c45..0ffff205478d 100644
--- a/drivers/net/wireless/ath/ath10k/pci.c
+++ b/drivers/net/wireless/ath/ath10k/pci.c
@@ -726,18 +726,12 @@ static void ath10k_pci_ce_recv_data(struct ath10k_ce_pipe *ce_state)
         unsigned int nbytes, max_nbytes;
         unsigned int transfer_id;
         unsigned int flags;
-        int err;
+        int err, num_replenish = 0;
 
         while (ath10k_ce_completed_recv_next(ce_state, &transfer_context,
                                              &ce_data, &nbytes, &transfer_id,
                                              &flags) == 0) {
-                err = ath10k_pci_post_rx_pipe(pipe_info, 1);
-                if (unlikely(err)) {
-                        /* FIXME: retry */
-                        ath10k_warn("failed to replenish CE rx ring %d: %d\n",
-                                    pipe_info->pipe_num, err);
-                }
-
+                num_replenish++;
                 skb = transfer_context;
                 max_nbytes = skb->len + skb_tailroom(skb);
                 dma_unmap_single(ar->dev, ATH10K_SKB_CB(skb)->paddr,
@@ -753,6 +747,13 @@ static void ath10k_pci_ce_recv_data(struct ath10k_ce_pipe *ce_state)
                 skb_put(skb, nbytes);
                 cb->rx_completion(ar, skb, pipe_info->pipe_num);
         }
+
+        err = ath10k_pci_post_rx_pipe(pipe_info, num_replenish);
+        if (unlikely(err)) {
+                /* FIXME: retry */
+                ath10k_warn("failed to replenish CE rx ring %d (%d bufs): %d\n",
+                            pipe_info->pipe_num, num_replenish, err);
+        }
 }
 
 static int ath10k_pci_hif_tx_sg(struct ath10k *ar, u8 pipe_id,