| From foo@baz Sat Nov 10 11:24:34 PST 2018 |
| From: Martin Willi <martin@strongswan.org> |
| Date: Wed, 22 Aug 2018 09:39:52 +0200 |
| Subject: ath10k: schedule hardware restart if WMI command times out |
| |
| From: Martin Willi <martin@strongswan.org> |
| |
| [ Upstream commit a9911937e7d332761e8c4fcbc7ba0426bdc3956f ] |
| |
| When running in AP mode, ath10k sometimes suffers from TX credit |
| starvation. The issue is hard to reproduce and shows up once in a |
| few days, but has been repeatedly seen with QCA9882 and a large |
| range of firmwares, including 10.2.4.70.67. |
| |
| Once the module is in this state, TX credits are never replenished, |
| which results in "SWBA overrun" errors, as no beacons can be sent. |
| Even worse, WMI commands run in a timeout while holding the conf |
| mutex for three seconds each, making any further operations slow |
| and the whole system unresponsive. |
| |
| The firmware/driver never recovers from that state automatically, |
| and triggering TX flush or warm restarts won't work over WMI. So |
| issue a hardware restart if a WMI command times out due to missing |
| TX credits. This implies a connectivity outage of about 1.4s in AP |
| mode, but brings back the interface and the whole system to a usable |
| state. WMI command timeouts have not been seen in absent of this |
| specific issue, so taking such drastic actions seems legitimate. |
| |
| Signed-off-by: Martin Willi <martin@strongswan.org> |
| Signed-off-by: Kalle Valo <kvalo@codeaurora.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/net/wireless/ath/ath10k/wmi.c | 6 ++++++ |
| 1 file changed, 6 insertions(+) |
| |
| --- a/drivers/net/wireless/ath/ath10k/wmi.c |
| +++ b/drivers/net/wireless/ath/ath10k/wmi.c |
| @@ -1822,6 +1822,12 @@ int ath10k_wmi_cmd_send(struct ath10k *a |
| if (ret) |
| dev_kfree_skb_any(skb); |
| |
| + if (ret == -EAGAIN) { |
| + ath10k_warn(ar, "wmi command %d timeout, restarting hardware\n", |
| + cmd_id); |
| + queue_work(ar->workqueue, &ar->restart_work); |
| + } |
| + |
| return ret; |
| } |
| |
