Subject: Re: iwlwifi: AX201 not using 2 receive streams
To:     Brandon Nielsen <nielsenb@jetfuse.net>,
        linux-wireless@vger.kernel.org
References: <3cb11500-6828-6ded-bebc-cdb6e1f97bc0@jetfuse.net>
 <521b0dba-5866-ff34-da5a-479bc95cc9d9@candelatech.com>
 <60724ae6-e8e2-183d-575a-0186e45c3fae@jetfuse.net>
From:   Ben Greear <greearb@candelatech.com>
Organization: Candela Technologies
Message-ID: <679864d0-25da-b3c7-b1da-c77deb52fd3a@candelatech.com>
Date:   Thu, 13 Jan 2022 09:12:17 -0800
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On 1/11/22 11:46 AM, Brandon Nielsen wrote:
> On 1/8/22 3:22 PM, Ben Greear wrote:
>> On 1/8/22 12:50 PM, Brandon Nielsen wrote:
>>> I have a system with Intel AX201 not using 2 spatial streams in the RX (download) direction. TX (upload) functions as expected. I'm seeing similar behavior 
>>> with an AX200 system. I'm seeing the same behavior on 5.15.12 as I am with 5.16.0-rc8 so I didn't mark it as a regression. Windows works as expected.
>>>
>>> I have opened bug 215465[0] with some more detail.
>>>
>>> [0] - https://bugzilla.kernel.org/show_bug.cgi?id=215465
>>>
>>
>> We saw something similar with ax210, but only on 6E, in kernel 5.15.7+. On 5Ghz, it worked 2x2 as expected.
>> On a 5.15.0-rc something, it worked OK for us.
>>
>> We verified same firmware is used in both cases, but have not fully bisected the problem yet but we are
>> working on it.  In case you find the problem patch before us, please let me know!
>>
>> Thanks,
>> Ben
>>
> 
> I'm still seeing this as far back as 5.11.12, so I'm not convinced this is a regression. At least for the 5 GHz / 802.11ac case.
> 

Our engineer Chuck Rekierre bisected the problem we saw to a patch that came in as part of a stable patch.

Please see his revert patch: [PATCH] Revert "iwlwifi: mvm: disable RX-diversity in powersave"
posted yesterday, and if you get a chance to test this, please let us know the results.

Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com