[RFT] ath10k: restart fw on tx-credit timeout

[Michal Kazior]

It makes little sense to continue and let
firmware-host state become inconsistent if a WMI
command can't be submitted to firmware.

This effectively prevents after-affects of
tx-credit starvation bug which include spurious
sta kickout events and inability to associate new
stations after some time when acting as AP.

This should also speed up recovery/teardown in
some cases when firmware stops responding for some
reason.

Signed-off-by: Michal Kazior <michal.kazior at tieto.com>
---
 drivers/net/wireless/ath/ath10k/wmi.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath10k/wmi.c b/drivers/net/wireless/ath/ath10k/wmi.c
index aeea1c7..776b257 100644
--- a/drivers/net/wireless/ath/ath10k/wmi.c
+++ b/drivers/net/wireless/ath/ath10k/wmi.c
@@ -1045,9 +1045,15 @@ int ath10k_wmi_cmd_send(struct ath10k *ar, struct sk_buff *skb, u32 cmd_id)
 		(ret != -EAGAIN);
 	}), 3*HZ);
 
-	if (ret)
+	if (ret) {
 		dev_kfree_skb_any(skb);
 
+		if (ret == -EAGAIN) {
+			ath10k_warn(ar, "firmware unresponsive, restarting..\n");
+			queue_work(ar->workqueue, &ar->restart_work);
+		}
+	}
+
 	return ret;
 }
 
-- 
1.8.5.3