Hi Ben,
Thanks for your help.
> If you use the -ct firmware and the -ct driver, you can configure
> more than 2 tx-credits.
Unfortunately, this didn't help, either. I hit these issues even sooner
with any 10.1-based firmware (including CT), which implies that at
least some of them have been addressed with 10.2/10.2.4.
> I am not sure it resolves everything and a buggy firmware would still
> cause issues no matter.
As a work-around, I'm experimenting with handling timeout conditions in
ath10k_wmi_cmd_send() caused by missing credits. Given that we can't do
any TX-flush or warm-restart over WMI under these conditions, I just
issue a hardware restart (patch below).
Some initial tests show that this in fact recovers the module from its
bad state with just a small connectivity gap; certainly much better
than that unpredictable behavior we've seen previously.
I'll do some more testing with this approach before considering to
upstream it.
Regards
Martin
---
>From fd9e90d0294450c093d243ee4f1eb1e07b1cd73a Mon Sep 17 00:00:00 2001
From: Martin Willi <martin@xxxxxxxxxxxxxx>
Date: Fri, 3 Aug 2018 14:23:30 +0200
Subject: [PATCH] ath10k: Schedule hardware restart if WMI command times out
If the TX queue gets stuck for some reason, we run out of tx credits and
are unable to send any commands over WMI. To recover from this situation,
issue a hard hardware restart. This implies a connectivity outage of about
1.4s in AP mode, but brings back the interface to a usable state.
Signed-off-by: Martin Willi <martin@xxxxxxxxxxxxxx>
---
drivers/net/wireless/ath/ath10k/wmi.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/net/wireless/ath/ath10k/wmi.c b/drivers/net/wireless/ath/ath10k/wmi.c
index 38a97086708b..d39a983f4a1f 100644
--- a/drivers/net/wireless/ath/ath10k/wmi.c
+++ b/drivers/net/wireless/ath/ath10k/wmi.c
@@ -1852,6 +1852,12 @@ int ath10k_wmi_cmd_send(struct ath10k *ar, struct sk_buff *skb, u32 cmd_id)
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;
}
--
2.17.1
