Subject: Re: [PATCH v1] ath10k: fix band_center_freq handling for VHT160 in
 recent firmwares
To: Ben Greear <greearb@candelatech.com>,
        Kalle Valo <kvalo@codeaurora.org>
Cc: linux-wireless@vger.kernel.org, ath10k@lists.infradead.org
References: <20180426094357.24358-1-s.gottschall@dd-wrt.com>
 <19b8766e-d474-31d3-ff38-993498ee670d@candelatech.com>
 <da5c7c56-9a41-99f0-28be-3a2c8e9fabbf@dd-wrt.com>
 <87wovr94ml.fsf@kamboji.qca.qualcomm.com>
 <71d17554-7727-cdfa-4a0d-5e1170dc32b7@candelatech.com>
From: Sebastian Gottschall <s.gottschall@dd-wrt.com>
Message-ID: <43553b5b-9e06-2a6a-098e-9223a7aeeac6@dd-wrt.com> (sfid-20180528_002606_274362_14A70FED)
Date: Mon, 28 May 2018 00:25:47 +0200
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Am 25.05.2018 um 16:52 schrieb Ben Greear:
> On 05/25/2018 07:44 AM, Kalle Valo wrote:
>> Sebastian Gottschall <s.gottschall@dd-wrt.com> writes:
>>
>>> Am 26.04.2018 um 15:44 schrieb Ben Greear:
>>>>
>>>>
>>>> On 04/26/2018 02:43 AM, s.gottschall@dd-wrt.com wrote:
>>>>> From: Sebastian Gottschall <s.gottschall@dd-wrt.com>
>>>>>
>>>>> starting with firmware 10.4.3.4.x series QCA changed the handling
>>>>> of the channel property band_center_freq1 and band_center_freq2 in
>>>>> vht160 operation mode
>>>>> likelly for backward compatiblity with vht80 only capable clients.
>>>>> this patch adjusts the handling to get vht160 to work again with
>>>>> official qca firmwares newer than 3.3
>>>>> consider that this patch will not work with older firmwares
>>>>> anymore. to avoid undefined behaviour this we disable vht160
>>>>> capability for outdated firmwares
>>>>
>>>> We should be able to use a feature-flag or otherwise determine if
>>>> the firmware needs the old or new
>>>> API and make the driver able to handle both.
>>>
>>> the new firmware must be used as is and it works. the old firmware can
>>> be detected on the missing vht cap flag.
>>> but thats not my task. i can only use feature flags if they are
>>> included within the qca firmwares. but they arent
>>> the old pre 3.3 firmwares should be treated as obsolete. they are more
>>> than 2 years old and do not announce vht160 capability
>>> even if it works with some ignorance, but on the other side the it has
>>> backward incompatiblies with older vht80 only clients.
>>> this is why the new way was introduced
>>
>> I was told ath10k could check for WMI_SERVICE_EXTENDED_NSS_SUPPORT flag.
>> Can someone test and verify that?
>>
>
> I do see that my firmware source based on older upstream QCA FW does 
> not advertise
> that flag, and newer QCA firmware does, so it would appear that test 
> might
> work.
but your sourcebase is new enough that this new handling is required.? 
if i remember correct this handling is required starting with 10.4-3.4 
source base
if a 3.4 original firmware is not providing that flag, it cannot be used 
for correct handling and yours is 3.4 based
>
> Thanks,
> Ben
>