Re: [PATCH RFC v2 0/4] wifi: ath10k: support board-specific firmware overrides

[Kalle Valo <kvalo@kernel.org>]

Dmitry Baryshkov <dmitry.baryshkov@linaro.org> writes:

> On Wed, 6 Mar 2024 at 11:04, Kalle Valo <kvalo@kernel.org> wrote:
>
>>
>> Dmitry Baryshkov <dmitry.baryshkov@linaro.org> writes:
>>
>> > On WCN3990 platforms actual firmware, wlanmdsp.mbn, is sideloaded to the
>> > modem DSP via the TQFTPserv. These MBN files are signed by the device
>> > vendor, can only be used with the particular SoC or device.
>> >
>> > Unfortunately different firmware versions come with different features.
>> > For example firmware for SDM845 doesn't use single-chan-info-per-channel
>> > feature, while firmware for QRB2210 / QRB4210 requires that feature.
>> >
>> > Allow board DT files to override the subdir of the fw dir used to lookup
>> > the firmware-N.bin file decribing corresponding WiFi firmware.
>> > For example, adding firmware-name = "qrb4210" property will make the
>> > driver look for the firmware-N.bin first in ath10k/WCN3990/hw1.0/qrb4210
>> > directory and then fallback to the default ath10k/WCN3990/hw1.0 dir.
>> >
>> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>> > ---
>> > Changes in v2:
>> > - Fixed the comment about the default board name being NULL (Kalle)
>> > - Expanded commit message to provide examples for firmware paths (Kalle)
>> > - Added a note regarding board-2.bin to the commit message (Kalle)
>> > - Link to v1:
>> > https://lore.kernel.org/r/20240130-wcn3990-firmware-path-v1-0-826b93202964@linaro.org
>>
>> From my point of view this looks good now but let's see what others say.
>> Is there a specific reason why you marked this as RFC still?
>
> No, I just forgot to remove it from the series settings, so you can
> consider it as final.

Good, so let's ignore the RFC label for this v2.

> I had one minor question in my head (but that's mostly for patches 3
> and 4): in linux-firmware we will have ath10k/WCN3990/hw1.0/qcm2290
> and make qrb4210 as a symlink to it. Is that fine from your POV? 

Yes, I think using a symlink is a good idea.

> Or should we use sensible device names (e.g. qcom-rb1)?

I guess 'qcom-rb1' refers to 'Qualcomm Robotics RB1' board? In other
words, the question is that should we use chipset specific names like
'qcm2290' or product based names like 'qcom-rb1'?

That's a good question for which I don't have a good answer :) I'm not
very familiar with WCN3990 hardware and SoCs to have a full picture of
all this, especially how the firmware images are signed or what
different firmware branches there are etc.

To be on the safe side using 'qcom-rb1' makes sense but on the other
hand that means we need to update linux-firmware (basically add a new
symlink) everytime a new product is added. But are there going to be
that many new ath10k based products?

Using 'qcm2290' is easier because for a new product then there only
needs to be a change in DTS and no need to change anything
linux-firmware. But here the risk is that if there's actually two
different ath10k firmware branches for 'qcm2290'. If that ever happens
(I hope not) I guess we could solve that by adding new 'qcm2290-foo'
directory?

But I don't really know, thoughts?

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