Subject: Re: [PATCH] ath10k: Introduce a devicetree quirk to skip host cap QMI requests

From: Kalle Valo <[email-masked]>
Date: Tue, 09 Feb 2021 10:10:44 +0200

Bjorn Andersson <[email-masked]> writes:

> On Mon 08 Feb 11:21 CST 2021, Kalle Valo wrote:
>
>> Amit Pundir <[email-masked]> writes:
>> 
>> > Hi Kalle,
>> >
>> > On Mon, 7 Dec 2020 at 22:25, Kalle Valo <[email-masked]> wrote:
>> >>
>> >> This is firmware version specific, right? There's also enum
>> >> ath10k_fw_features which is embedded within firmware-N.bin, we could add
>> >> a new flag there. But that means that a correct firmware-N.bin is needed
>> >> for each firmware version, not sure if that would work out. Just
>> >> throwing out ideas here.
>> >
>> > Apologies for this late reply. I was out for a while.
>> 
>> No worries.
>> 
>> > If by that (the firmware version) you mean "QC_IMAGE_VERSION_STRING",
>> > then that may be a bit tricky. Pocophone F1 use the same firmware
>> > family version (WLAN.HL.2.0.XXX), used by Dragonboard 845c (which has
>> > Wi-Fi working upstream).
>> 
>> I'm meaning the ath10k firmware meta data we have in firmware-N.bin
>> (N=2,3,4...) file. A quick summary:
>> 
>> Every ath10k firmware release should have firmware-N.bin. The file is
>> created with this tool:
>> 
>> https://github.com/qca/qca-swiss-army-knife/blob/master/tools/scripts/ath10k/ath10k-fwencoder
>> 
>> firmware-N.bin contains various metadata, one of those being firmware
>> feature flags:
>> 
>> enum ath10k_fw_features {
>> 	/* wmi_mgmt_rx_hdr contains extra RSSI information */
>> 	ATH10K_FW_FEATURE_EXT_WMI_MGMT_RX = 0,
>> 
>> 	/* Firmware from 10X branch. Deprecated, don't use in new code. */
>> 	ATH10K_FW_FEATURE_WMI_10X = 1,
>> 
>>         [...]
>> 
>> So what you could is add a new flag enum ath10k_fw_features, create a
>> new firmware-N.bin for your device and enable the flag on the firmware
>> releases for your device only.
>> 
>> I don't know if this is usable, but one solution which came to my mind.
>
> It sounds quite reasonable to pass this using firmawre-N.bin instead of
> DT, however that would imply that we need to find firmware-N.bin in the
> device-specific directory, where we keep the wlanmdsp.mbn as well - and
> not under /lib/firmware/ath10k
>
> For other devices (e.g. ADSP, modem or wlanmdsp.mbn) we're putting these
> in e.g. /lib/firmware/qcom/LENOVO/81JL/ and specifies the location using
> a firmware-name property in DT.

Ah, I didn't realise that.

Actually I would like to have ath10k in control[1] of QMI/rproc firmware
loading as the firmware releases have different constraints, like the
issue we are now discussing. Ideally firmware-N.bin would contain all
firmware files, for example wlanmdsp.mbn, and from the meta data
ath10k/ath11k would know what version of the firmware interface should
be used.

I remember we discussed this briefly a year or two ago and there was no
easy solution, but I really wish we could find one. More these kind of
firmware interface incompatibilities will most likely pop up, also in
ath11k, so it would be great to find a clean and easily maneagable
solution.

[1] With control I mean that ath10k/ath11k can choose which firmware
should be loaded

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