Subject: Re: AP mode with Broadcom 4330
To: Russell King - ARM Linux <linux@armlinux.org.uk>
References: <20170728141503.GU31807@n2100.armlinux.org.uk>
 <20170728174930.GA3313@n2100.armlinux.org.uk>
 <2c5d4ef0-9b87-0084-c032-c5614275dd56@broadcom.com>
 <20170731125902.GW31807@n2100.armlinux.org.uk>
 <6f701504-0315-a49a-58d9-5cc9292d7d77@broadcom.com>
 <20171114230723.GB31757@n2100.armlinux.org.uk>
Cc: linux-wireless@vger.kernel.org,
        brcm80211-dev-list.pdl@broadcom.com, brcm80211-dev-list@cypress.com
From: Arend van Spriel <arend.vanspriel@broadcom.com>
Message-ID: <5A0BFF12.2060401@broadcom.com> (sfid-20171115_094725_079881_08B2C1A0)
Date: Wed, 15 Nov 2017 09:47:14 +0100
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Sender: linux-wireless-owner@vger.kernel.org

On 11/15/2017 12:07 AM, Russell King - ARM Linux wrote:
> Arend,
>
> Did this bug ever get fixed, or are 4330's still ending up advertising
> BCRM_TEST_SSID when they're put into AP mode with mainline kernels?
>
> It would be good to know whether I can drop my patch for this from my
> kernel tree and still have working AP mode.

Hi Russell,

For now keep it as this thread got dusty on my end. Sorry about that. I 
can submit a patch for brcmfmac disabling mbss, which may be what you 
are carrying in your kernel tree right now. As 4330 is out there for a 
while I guess it is good to make it a stable patch.

Regards,
Arend

> Thanks.
>
> On Mon, Jul 31, 2017 at 10:28:50PM +0200, Arend van Spriel wrote:
>> On 31-07-17 14:59, Russell King - ARM Linux wrote:
>>> On Fri, Jul 28, 2017 at 09:50:21PM +0200, Arend van Spriel wrote:
>>>> I was going to agree with you, but having second thoughts. There are
>>>> actually two use-cases that need to be handled properly. The regular AP
>>>> case and the MBSS case. In case of MBSS the initial AP interface will
>>>> have mbss set to false and subsequent AP interfaces will have mbss set
>>>> to true, but in firmware this has to be configured inverted. That is
>>>> what the code above is doing. However, this indeed breaks the regular AP
>>>> case for firmwares that abuse that setting for testing purposes (no idea
>>>> why that is in a released firmware).
>>>
>>> Maybe detect the BCRM_TEST_SSID string in the firmware file (as it's
>>> broken up amongst other data, it's not trivial) and disable mbss for
>>> such firmware?  Alternatively, maybe blacklist mbss for some firmware
>>> versions?
>>
>> Well. It seem 43362 chip also had this and we disabled mbss for that
>> chipset. So we may do that for 4330 as well.
>>
>>> Do the firmware versions that include this "abuse" actually have
>>> functional mbss?
>>
>> Digging through our internal bug database I found a remark that
>> BRCM_TEST_SSID showing up means mbss is not functional.
>>
>>> There's also the obvious question: which firmware is recommended for
>>> the 4330?
>>
>> We tend to rely on what is released to AOSP as our team does not have
>> the bandwidth to go through the release process. I checked and it is
>> still the same so matches what is in linux-firmware.
>>
>> Regards,
>> Arend
>