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From:   Kalle Valo <kvalo@codeaurora.org>
To:     Felix Fietkau <nbd@nbd.name>
Cc:     linux-wireless@vger.kernel.org, hurricos@gmail.com
Subject: Re: [PATCH] ath9k: fix transmitting to stations in dynamic SMPS mode
References: <20210214184911.96702-1-nbd@nbd.name>
        <8735xyrkvy.fsf@codeaurora.org>
        <d668f30a-f911-921f-d329-f6ac872d0bcc@nbd.name>
Date:   Mon, 15 Feb 2021 11:12:06 +0200
In-Reply-To: <d668f30a-f911-921f-d329-f6ac872d0bcc@nbd.name> (Felix Fietkau's
        message of "Mon, 15 Feb 2021 08:20:04 +0100")
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Felix Fietkau <nbd@nbd.name> writes:

> On 2021-02-15 05:54, Kalle Valo wrote:
>> Felix Fietkau <nbd@nbd.name> writes:
>> 
>>> When transmitting to a receiver in dynamic SMPS mode, all transmissions that
>>> use multiple spatial streams need to be sent using CTS-to-self or RTS/CTS to
>>> give the receiver's extra chains some time to wake up.
>>> This fixes the tx rate getting stuck at <= MCS7 for some clients, especially
>>> Intel ones, which make aggressive use of SMPS.
>>>
>>> Cc: stable@vger.kernel.org
>>> Reported-by: Martin Kennedy <hurricos@gmail.com>
>>> Signed-off-by: Felix Fietkau <nbd@nbd.name>
>> 
>> No Fixes tag so I assume this is not a regression?
>> 
>> Should this go to v5.12 or -next? I guess that depends how much testing
>> this patch has got.
>
> I'd prefer v5.12. I got confirmation that the patch makes a big
> difference in throughput with Intel clients (makes tx with MCS > 7
> work), and I think there is very little potential for regressions.

Good, I'll queue this to v5.12 then. And we have plenty of time to fix
any regressions anyway.

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