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Date:   Fri, 18 Nov 2022 17:47:12 +0100
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Subject: Re: [PATCH v2] brcmfmac: Add support for BCM43596 PCIe Wi-Fi
To:     Kalle Valo <kvalo@kernel.org>,
        =?UTF-8?Q?Alvin_=c5=a0ipraga?= <ALSI@bang-olufsen.dk>
Cc:     Linus Walleij <linus.walleij@linaro.org>,
        Hector Martin <marcan@marcan.st>,
        "~postmarketos/upstreaming@lists.sr.ht" 
        <~postmarketos/upstreaming@lists.sr.ht>,
        "martin.botka@somainline.org" <martin.botka@somainline.org>,
        "angelogioacchino.delregno@somainline.org" 
        <angelogioacchino.delregno@somainline.org>,
        "marijn.suijten@somainline.org" <marijn.suijten@somainline.org>,
        "jamipkettunen@somainline.org" <jamipkettunen@somainline.org>,
        Arend van Spriel <aspriel@gmail.com>,
        Franky Lin <franky.lin@broadcom.com>,
        Hante Meuleman <hante.meuleman@broadcom.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, Marek Vasut <marex@denx.de>,
        "Zhao, Jiaqing" <jiaqing.zhao@intel.com>,
        "Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>,
        Soon Tak Lee <soontak.lee@cypress.com>,
        "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
        "brcm80211-dev-list.pdl@broadcom.com" 
        <brcm80211-dev-list.pdl@broadcom.com>,
        "SHA-cyfmac-dev-list@infineon.com" <SHA-cyfmac-dev-list@infineon.com>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
References: <20220921001630.56765-1-konrad.dybcio@somainline.org>
 <83b90478-3974-28e6-cf13-35fc4f62e0db@marcan.st>
 <13b8c67c-399c-d1a6-4929-61aea27aa57d@somainline.org>
 <0e65a8b2-0827-af1e-602c-76d9450e3d11@marcan.st>
 <7fd077c5-83f8-02e2-03c1-900a47f05dc1@somainline.org>
 <CACRpkda3uryD6TOEaTi3pPX5No40LBWoyHR4VcEuKw4iYT0dqA@mail.gmail.com>
 <20220922133056.eo26da4npkg6bpf2@bang-olufsen.dk> <87sfke32pc.fsf@kernel.org>
From:   Konrad Dybcio <konrad.dybcio@linaro.org>
In-Reply-To: <87sfke32pc.fsf@kernel.org>
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On 26/09/2022 11:27, Kalle Valo wrote:
> Alvin Šipraga <ALSI@bang-olufsen.dk> writes:
> 
>> On Thu, Sep 22, 2022 at 03:02:12PM +0200, Linus Walleij wrote:
>>> On Thu, Sep 22, 2022 at 12:21 PM Konrad Dybcio
>>> <konrad.dybcio@somainline.org> wrote:
>>>
>>>> Also worth noting is the 'somc' bit, meaning there are probably *some* SONY
>>>> customizations, but that's also just a guess.
>>>
>>> What I have seen from BRCM customizations on Samsung phones is that
>>> the per-device customization of firmware seems to involve the set-up of
>>> some GPIO and power management pins. For example if integrated with
>>> an SoC that has autonomous system resume, or if some GPIO line has
>>> to be pulled to enable an external regulator or PA.
>>
>> At least with Infineon (formerly Cypress), as a customer you might get a
>> private firmware and this will be maintained internally by them on a
>> separate customer branch. Any subsequent bugfixes or feature requests
>> will usually be applied to that customer branch and a new firmware built
>> from it. I think their internal "mainline" branch might get merged into
>> the customer branches from time to time, but this seems to be done on an
>> ad-hoc basis. This is our experience at least.
>>
>> I would also point out that the BCM4359 is equivalent to the
>> CYW88359/CYW89359 chipset, which we are using in some of our
>> products. Note that this is a Cypress chipset (identifiable by the
>> Version: ... (... CY) tag in the version string). But the FW Konrad is
>> linking appears to be for a Broadcom chipset.
>>
>> FYI, here's a publicly available set of firmware files for the '4359:
>>
>> https://github.com/NXP/imx-firmware/tree/master/cyw-wifi-bt/1FD_CYW4359
>>
>> Anyway, I would second Hector's suggestion and make this a separate FW.
> 
> I also recommend having a separate firmware filename. Like Hector said,
> it's easy to have a symlink in userspace if same binary can be used.
So, I dusted off this patch and tried to change the fw name, only to 
discover that the BRCM_PCIE_43596_DEVICE_ID is equal to 
CY_PCIE_89459_DEVICE_ID, (which btw uses 4355/89459 fw), but then it 
makes the driver expect 4359/9 based on rev matching, so... the 43596 
chip ID may be a lie? Or at least for the one used in my particular 
device? I'm beyond confused now..

I can think of a couple of hacky ways to force use of 43596 fw, but I 
don't think any would be really upstreamable..

Any thoughts?

Konrad