Re: [PATCH v2] brcmfmac: Add support for BCM43596 PCIe Wi-Fi

[Konrad Dybcio]

On 26/09/2022 11:27, Kalle Valo wrote:
> Alvin Šipraga <ALSI@xxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxx> 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