Re: Research + questions on brcmfmac and support for monitor mode

["Rafał Miłecki" <zajec5@gmail.com>]

On 19.06.2018 09:53, Arend van Spriel wrote:
> On 6/19/2018 9:27 AM, Rafał Miłecki wrote:
>> On Mon, 11 Jun 2018 at 12:48, Arend van Spriel
>> <arend.vanspriel@broadcom.com> wrote:
>>> On 5/30/2018 1:52 PM, Rafał Miłecki wrote:
>>>> I'm providing extra version info of tested firmware images as requested
>>>> by Arend in another e-mail thread.
>>>
>>> Looking into our firmware repo it there are two flags, ie. WL_MONITOR
>>> and WL_RADIOTAP. It seems both are set for firmware containing -stamon-
>>> feature. Your list below confirms that. I still plan to add indication
>>> for WL_RADIOTAP in the "cap" iovar, but a stamon feature check could be
>>> used for older firmwares.
>>
>> I just checked wl.mk (it's an open source file) and found following line:
>> WLFILES_SRC_HI += src/wl/sys/wlc_stamon.c
>> not guarded by any ifeq.
> 
> wl.mk is used for NIC driver (softmac) so it is not used for fullmac firmware.

Weird. I see a few rte references in wl.mk which suggests it's used for
both (softmac & fullmac firmware).


>> It appears wlc_stamon.c is always being compiled in. Are you 100% sure
>> that wlc_stamon.c depends & uses radiotap? Are you sure it's
>> impossible to include stamon support without radiotap support?
>>
>> I'm asking because we're going to check "sta_monitor" iovar to find
>> out if radiotap support is included. I'd like to be sure it's 100%
>> reliable.
> 
> I have already created a patch for this (see below). I will submit it this week.

Just to be clear could you also answer my above question, please?

Did you check if it's impossible to build firmware *with* stamon.c (and
sta_monitor iovar) and *without WL_RADIOTAP?


> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/feature.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/feature.c
> index f70fec6..67d7fc7 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/feature.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/feature.c
> @@ -207,6 +207,7 @@ void brcmf_feat_attach(struct brcmf_pub *drvr)
>       struct brcmf_if *ifp = brcmf_get_ifp(drvr, 0);
>       struct brcmf_pno_macaddr_le pfn_mac;
>       struct brcmf_gscan_config gscan_cfg;
> +    struct brcmf_stamon_sta_config stamon_cfg;
>       u32 wowl_cap;
>       s32 err;
> 
> @@ -217,6 +218,20 @@ void brcmf_feat_attach(struct brcmf_pub *drvr)
>           brcmf_feat_iovar_data_set(ifp, BRCMF_FEAT_GSCAN,
>                         "pfn_gscan_cfg",
>                         &gscan_cfg, sizeof(gscan_cfg));
> +
> +    if (!brcmf_feat_is_enabled(ifp, BRCMF_FEAT_MONITOR) ||
> +        !brcmf_feat_is_enabled(ifp, BRCMF_FEAT_RADIOTAP)) {
> +        ifp->fwil_fwerr = true;
> +        memset(&stamon_cfg, 0, sizeof(stamon_cfg));
> +        /* iovar requires IOVF_SET_UP so this fails either way */
> +        err = brcmf_fil_iovar_data_set(ifp, "sta_monitor", &stamon_cfg,
> +                           sizeof(stamon_cfg));

I think it may be simpler (and maybe less invasive) to use
brcmf_fil_iovar_data_get.


> +        if (err != BRCMF_FW_UNSUPPORTED) {
> +            ifp->drvr->feat_flags |= BRCMF_FEAT_MONITOR;
> +            ifp->drvr->feat_flags |= BRCMF_FEAT_RADIOTAP;
> +        }
> +        ifp->fwil_fwerr = false;
> +    }