AP mode firmware crash on QCA9880-BR4A

[Martin Blumenstingl]

Hi Michal,

sorry for the delay, I was very busy for the past week.
But now I am back with news.
To keep it simple, all of my new findings below are with ath10k
firmware 10.2.4.70-2.
The wireless drivers were also updated in OpenWrt: "Loading modules
backported from Linux version master-2015-07-21-0-g47cd203"

On Thu, Jul 23, 2015 at 7:50 AM, Michal Kazior <michal.kazior at tieto.com> wrote:
> Yes, this should be enough. You'll want to add/keep a print to know
> how many SWBA event come in though.
I have used this patch [0] to make ath10k_wmi_event_host_swba only do
printk("%s()\n", __func__);
Result: firmware is not crashing - kernel log can be seen here: [1]

> Perhaps not submitting beacons will prevent the crash or it'll postpone it until
> after more SWBA events are delivered than before.
I also tried that by #if 0'ing everything starting at "if
(!arvif->beacon_buf)" until "trace_ath10k_tx_payload(ar, bcn->data,
bcn->len);". The patch for this can be seen here: [2]
The result: firmware is still not crashing - kernel log can be seen here: [3]

Without any patches at all (only a printk at the start of
ath10k_wmi_event_host_swba), this is the result the same as with old
wireless driver versions: firmware crashes, see [5]

Let me know what the next steps are - I'm sure we can fix this nasty bug! :-)


Regards,
Martin

[0] https://paste.kde.org/p7osjjjys
[1] https://paste.kde.org/pevltyu4z
[2] https://paste.kde.org/pexn9n4ao
[3] https://paste.kde.org/pgjf9xv4w
[5] https://paste.kde.org/p2xxmpoiz