Re: [PATCH] mwifiex: Ignore BTCOEX events from the 88W8897 firmware

From: Bjorn Helgaas
Date: Mon Nov 29 2021 - 18:38:32 EST


On Mon, Nov 29, 2021 at 05:32:11PM -0600, Bjorn Helgaas wrote:
> On Wed, Nov 03, 2021 at 09:58:27PM +0100, Jonas Dreßler wrote:
> > The firmware of the 88W8897 PCIe+USB card sends those events very
> > unreliably, sometimes bluetooth together with 2.4ghz-wifi is used and no
> > COEX event comes in, and sometimes bluetooth is disabled but the
> > coexistance mode doesn't get disabled.
>
> s/sends those events/sends BTCOEX events/ so it reads well without the
> subject.
>
> s/coexistance/coexistence/
>
> Is BTCOEX a standard Bluetooth thing? Is there a spec reference that
> could be useful here? I've never seen those specs, so this is just
> curiosity. I did download the "Bluetooth Core Spec v5.3", which does
> have a "Wireless Coexistence Signaling and Interfaces" chapter, but
> "BTCOEX" doesn't appear in that doc.
>
> > This means we sometimes end up capping the rx/tx window size while
> > bluetooth is not enabled anymore, artifically limiting wifi speeds even
> > though bluetooth is not being used.
>
> s/artifically/artificially/
>
> > Since we can't fix the firmware, let's just ignore those events on the
> > 88W8897 device. From some Wireshark capture sessions it seems that the
> > Windows driver also doesn't change the rx/tx window sizes when bluetooth
> > gets enabled or disabled, so this is fairly consistent with the Windows
> > driver.

I hadn't read far enough to see that the patch was already applied,
sorry for the noise :)