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

From: Robert Marko <robimarko@gmail.com>
To: Kalle Valo <kvalo@kernel.org>
Cc: kvalo@codeaurora.org, davem@davemloft.net, kuba@kernel.org,
	ath10k@lists.infradead.org, linux-wireless@vger.kernel.org,
	netdev@vger.kernel.org, open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] ath10k: support bus and device specific API 1 BDF selection
Date: Wed, 8 Dec 2021 13:21:47 +0100	[thread overview]
Message-ID: <CAOX2RU5mqUfPRDsQNSpVPdiz6sE_68KN5Ae+2bC_t1cQzdzgTA@mail.gmail.com> (raw)
In-Reply-To: <163890036783.24891.8718291787865192280.kvalo@kernel.org>

On Tue, 7 Dec 2021 at 19:06, Kalle Valo <kvalo@kernel.org> wrote:
>
> Robert Marko <robimarko@gmail.com> 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@gmail.com>
>
> 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.

Regards,
Robert
>
> --
> https://patchwork.kernel.org/project/linux-wireless/patch/20211009221711.2315352-1-robimarko@gmail.com/
>
> https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
>