[PATCH 4/4] ath10k: fix spurious tx/rx during boot

[Michal Kazior]

On 17 September 2016 at 00:37, Hsu, Ryan <ryanhsu at qca.qualcomm.com> wrote:
[...]
>> +     /* WMI and HTT may use separate HIF pipes and are not guaranteed to be
>> +      * serialized properly implicitly.
>> +      *
>> +      * Moreover (most) WMI commands have no explicit acknowledges. It is
>> +      * possible to infer it implicitly by poking firmware with echo
>> +      * command - getting a reply means all preceding comments have been
>> +      * (mostly) processed.
>> +      *
>> +      * In case of vdev create/delete this is sufficient.
>> +      *
>> +      * Without this it's possible to end up with a race when HTT Rx ring is
>> +      * started before vdev create/delete hack is complete allowing a short
>> +      * window of opportunity to receive (and Tx ACK) a bunch of frames.
>> +      */
>> +     ret = ath10k_wmi_barrier(ar);
> QCA6174 UTF firmware seems doesn't support the WMI_ECHO command.
>
> [16460.274822] ath10k_pci 0000:04:00.0: wmi tlv echo value 0x0ba991e9
> ...
> [16463.461970] ath10k_pci 0000:04:00.0: failed to ping firmware: -110
> [16463.461975] ath10k_pci 0000:04:00.0: failed to reset rx filter: -110
>
> Has anyone verified any AP solution to see if UTF mode is still working
> with after this patch?
>
> Anyway, I would like to exclude the workaround from all solution's UTF mode.
>
> Michal any concerns? (or maybe just for QCA61x4 if any...)

I didn't expect UTF wouldn't support echo.. Sorry!

If you skip this workaround for UTF I guess the device will (again) be
able to generate some bogus traffic on boot for UTF case. Not sure how
much of a problem that is (assuming it is at all).


Michal