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

From: Amit Pundir <amit.pundir@linaro.org>
To: Kalle Valo <kvalo@codeaurora.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Rob Herring <robh@kernel.org>
Cc: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>,
	netdev@vger.kernel.org, linux-wireless@vger.kernel.org,
	lkml <linux-kernel@vger.kernel.org>,
	ath10k <ath10k@lists.infradead.org>,
	Konrad Dybcio <konradybcio@gmail.com>,
	dt <devicetree@vger.kernel.org>,
	David S Miller <davem@davemloft.net>,
	John Stultz <john.stultz@linaro.org>,
	Jakub Kicinski <kuba@kernel.org>,
	Sumit Semwal <sumit.semwal@linaro.org>
Subject: Re: [PATCH] ath10k: Introduce a devicetree quirk to skip host cap QMI requests
Date: Thu, 20 May 2021 17:17:52 +0530	[thread overview]
Message-ID: <CAMi1Hd2g68U8LVng2+RmhD+zFLqW8vcHS54FvaKxNF+BMs_tZg@mail.gmail.com> (raw)
In-Reply-To: <87blctveyj.fsf@codeaurora.org>

Hi,

Reviving this old thread again, to check if there are still any hopes
of landing this patch upstream.

Based on the feedback I have got so far, there are no easy way to skip
this part of the initialization at runtime. Bjorn and Kalle discussed
the possibility of creating device specific firmware-N.bin firmware
file but that would mean firmware-N.bin has to be loaded from the
device-specific directory along with wlanmdsp.bin. And ideally making
ath10k/ath11k in-charge of firmware loading, but there doesn't seem to
be a consensus on this either(?)

Regards,
Amit Pundir

On Tue, 9 Feb 2021 at 13:41, Kalle Valo <kvalo@codeaurora.org> wrote:
>
> Bjorn Andersson <bjorn.andersson@linaro.org> writes:
>
> > On Mon 08 Feb 11:21 CST 2021, Kalle Valo wrote:
> >
> >> Amit Pundir <amit.pundir@linaro.org> writes:
> >>
> >> > Hi Kalle,
> >> >
> >> > On Mon, 7 Dec 2020 at 22:25, Kalle Valo <kvalo@codeaurora.org> 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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>
> https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches