wil6210: guarantee safe access to rx descriptors shared memory

add memory barrier after allocating new rx descriptors, before
updating the hwtail.
This will guarantee that all writes to descriptors (shared memory)
are done before committing them to HW.

Signed-off-by: Maya Erez <qca_merez@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

diff --git a/drivers/net/wireless/ath/wil6210/txrx.c b/drivers/net/wireless/ath/wil6210/txrx.c
index fa6ea24a1309ed5b35e5eaaec0abb06f96b86cff..3909af171badee2e62cb20b750be0aa1f7e36862 100644 (file)
--- a/drivers/net/wireless/ath/wil6210/txrx.c
+++ b/drivers/net/wireless/ath/wil6210/txrx.c
@@ -544,6 +544,12 @@ static int wil_rx_refill(struct wil6210_priv *wil, int count)
                        break;
                }
        }
+
+       /* make sure all writes to descriptors (shared memory) are done before
+        * committing them to HW
+        */
+       wmb();
+
        wil_w(wil, v->hwtail, v->swtail);
 
        return rc;