Re: wifi breakage due to commit "wifi: brcmfmac: add support for vendor-specific firmware api"

[Arend van Spriel <arend.vanspriel@xxxxxxxxxxxx>]

On 3/15/2023 9:53 AM, Michael Stapelberg wrote:
> Hey Arend
>
> On Wed, 15 Mar 2023 at 09:33, Arend Van Spriel
> <arend.vanspriel@xxxxxxxxxxxx> wrote:
> > On March 15, 2023 8:58:43 AM Michael Stapelberg
> > <michael+lkml@xxxxxxxxxxxxx> wrote:
> >
> > > Hey Arend
> > >
> > > Thanks for taking a look.
> > >
> > > The brcmfmac-wcc module is present on my installation, but I’m not
> > > currently loading it.
> > > (I only load brcmutil, then brcmfmac.)
> > >
> > > But, even if I load it, the wlan0 interface still doesn’t show up.
> > >
> > > In the modules.dep, I see that brcmfmac-wcc should be loaded after
> > > brcmutil and brcmfmac.
> > > Is that accurate?
> >
> > Yes. Actually brcmfmac loads brcmfmac-wcc by itself.
>
> Hmm, when I run lsmod after booting, I don’t see it:
>
> /tmp/breakglass1452371198 # lsmod
> hci_uart 61440 0 - Live 0xffffba314a2cd000
> btbcm 24576 1 hci_uart, Live 0xffffba314a2c6000
> bluetooth 786432 3 hci_uart,btbcm, Live 0xffffba314a205000
> brcmfmac 258048 0 - Live 0xffffba314a1c5000
> brcmutil 20480 1 brcmfmac, Live 0xffffba314a1bf000
> ecdh_generic 16384 1 bluetooth, Live 0xffffba314a1ba000
> ecc 36864 1 ecdh_generic, Live 0xffffba314a1b0000
> /tmp/breakglass1452371198 #

That is expected as the log shows:

>>>>>>> + brcmfmac: brcmf_fwvid_request_module: mod=wcc: failed -2
>>>>>>> + ieee80211 phy0: brcmf_attach: brcmf_fwvid_attach failed

So in brcmf_fwvid_request_module it tries to load brcmfmac-wcc, but for 
some reason it fails.

> How does the “load by itself” mechanism work?
> Maybe I’m missing a userspace component for it.

I think it works pretty similar to firmware loading. These days firmware 
loading does not rely on a user-space helper and I assumed the same is 
true for module loading. Will look into it.

Regards,
Arend

> Thanks
>
> > > My installation is somewhat unusual in that I use a custom userland
> > > (see https://gokrazy.org/).
> >
> > Bit tricky choice of name :-p I will check it out.
> >
> > Regards,
> > Arend
> >
> > > Thanks
> > > Best regards
> > > Michael
> > >
> > >
> > > On Wed, 15 Mar 2023 at 00:21, Arend Van Spriel
> > > <arend.vanspriel@xxxxxxxxxxxx> wrote:
> > > > On March 14, 2023 11:49:05 PM Michael Stapelberg
> > > > <michael+lkml@xxxxxxxxxxxxx> wrote:
> > > >
> > > > > Of course, find it attached. Thanks.
> > > >
> > > > Strange. Could it be there is some build config needed to install the
> > > > additional kernel modules (brcmfmac-wcc.ko, etc.) on RPi image?
> > > >
> > > > Regards,
> > > > Arend
> > > >
> > > > > On Tue, 14 Mar 2023 at 23:26, Arend Van Spriel
> > > > > <arend.vanspriel@xxxxxxxxxxxx> wrote:
> > > > > > On March 14, 2023 8:39:05 PM Michael Stapelberg
> > > > > > <michael+lkml@xxxxxxxxxxxxx> wrote:
> > > > > >
> > > > > > > Hey Arend
> > > > > > >
> > > > > > > I recently bisected a user-reported WiFi breakage on the Raspberry Pi
> > > > > > > 3B+ to your commit
> > > > > > > https://github.com/torvalds/linux/commit/d6a5c562214f26e442c8ec3ff1e28e16675d1bcf
> > > > > > > https://lore.kernel.org/r/20221129135446.151065-4-arend.vanspriel@xxxxxxxxxxxx
> > > > > > >
> > > > > > > On our end, the issue was reported here:
> > > > > > > https://github.com/gokrazy/wifi/issues/3
> > > > > > >
> > > > > > > As of Linux 6.2.6, this seems to still be unfixed, so I wanted to
> > > > > > > check in and see if you could take a look please?
> > > > > >
> > > > > > I have a suspicion, but can you provide the kernel .config file so I can
> > > > > > see if I am on the right track.
> > > > > >
> > > > > > > + brcmfmac: brcmf_fwvid_request_module: mod=wcc: failed -2
> > > > > > > + ieee80211 phy0: brcmf_attach: brcmf_fwvid_attach failed
> > > > > > > + brcmfmac: brcmf_sdio_firmware_callback: brcmf_attach failed
> > > > > >
> > > > > > Regards,
> > > > > > Arend

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