Re: [PATCH] ath10k: support bus and device specific API 1 BDF selection

[Christian Lamparter]

On 08/12/2021 13:21, Robert Marko wrote:
> On Tue, 7 Dec 2021 at 19:06, Kalle Valo <kvalo@xxxxxxxxxx> wrote:
> > Robert Marko <robimarko@xxxxxxxxx> wrote:
> >
> > > Some ath10k IPQ40xx devices like the MikroTik hAP ac2 and ac3 require the
> > > BDF-s to be extracted from the device storage instead of shipping packaged
> > > API 2 BDF-s.
> > >
> > > This is required as MikroTik has started shipping boards that require BDF-s
> > > to be updated, as otherwise their WLAN performance really suffers.
> > > This is however impossible as the devices that require this are release
> > > under the same revision and its not possible to differentiate them from
> > > devices using the older BDF-s.
> > >
> > > In OpenWrt we are extracting the calibration data during runtime and we are
> > > able to extract the BDF-s in the same manner, however we cannot package the
> > > BDF-s to API 2 format on the fly and can only use API 1 to provide BDF-s on
> > > the fly.
> > > This is an issue as the ath10k driver explicitly looks only for the
> > > board.bin file and not for something like board-bus-device.bin like it does
> > > for pre-cal data.
> > > Due to this we have no way of providing correct BDF-s on the fly, so lets
> > > extend the ath10k driver to first look for BDF-s in the
> > > board-bus-device.bin format, for example: board-ahb-a800000.wifi.bin
> > > If that fails, look for the default board file name as defined previously.
> > >
> > > Signed-off-by: Robert Marko <robimarko@xxxxxxxxx>
> >
> > Can someone review this, please? I understand the need for this, but the board
> > handling is getting quite complex in ath10k so I'm hesitant.
> >
> > What about QCA6390 and other devices. Will they still work?
> Hi Kalle,
> everything else should just continue working as before unless the
> board-bus-device.bin file
> exists it will just use the current method to fetch the BDF.
>
> Also, this only applies to API1 BDF-s.
>
> We are really needing this as currently there are devices with the
> wrong BDF being loaded as
> we have no way of knowing where MikroTik changed it and dynamic
> loading would resolve
> all of that since they are one of the rare vendors that embed the
> BDF-s next to calibration data.

Isn't the only user of this the non-upstreamable rb_hardconfig
mikrotik platform driver? So, in your case the devices in question
needs to setup a detour through the userspace firmware (helper+scripts)
to pull on the sysfs of that mikrotik platform driver? Wouldn't it
be possible to do this more directly?

Cheers,
Christian