From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from e3i670.smtp2go.com (e3i670.smtp2go.com [158.120.86.158]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 409CC43C072 for ; Thu, 26 Feb 2026 16:23:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=158.120.86.158 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772123021; cv=none; b=tPInv8qg4qgN41E3cXaUhy6trjtSZ7QCprFJYsch+zAnpG4LDkmfFEBd++FE5PUDWoGDBYHJpwJnLHKDv1UC48vtJZ54LltyIeDWJ07yC3N3C8Ob7k1HeRRlsErMPeO1iMMLXu+RvMmELbvbiUCrnA3bn+z80SWveI3jVzHym3U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772123021; c=relaxed/simple; bh=4OlT4z6nXwiQ1hsBUOWkFfhSKpAvXJIKhb8uEx+N/n8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cHzMSE3Za61b1IJBdRliPbi9bbOwaCDDsArhrNy3AAJ5KG3Ah5aqS7PvkugK2vfs/ygdWTbyK67adsaPo7EZ42wadY1YPenv93SjnPZC+O/C+N+l6pzwnM8AdTGIMJbeJdoTk9Sgto3rDwhAB2uAKAtRdCJmV+wETKfaEMPpa58= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=triplefau.lt; spf=pass smtp.mailfrom=em510616.triplefau.lt; dkim=pass (2048-bit key) header.d=triplefau.lt header.i=@triplefau.lt header.b=Nk2apamI; arc=none smtp.client-ip=158.120.86.158 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=triplefau.lt Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=em510616.triplefau.lt Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=triplefau.lt header.i=@triplefau.lt header.b="Nk2apamI" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=triplefau.lt; i=@triplefau.lt; q=dns/txt; s=s510616; t=1772122111; h=from : subject : to : message-id : date; bh=lzPuixvWghzNpH0Uka8bHYTOqSCBdAw6KoT3MIt+FGg=; b=Nk2apamI7FJwjDzQqIM9vAVtVVhZSGwy885Q0EqG06cNefCrqxZa5xm7KRQX0AhBDG4+r KEkfDxDR/uzqG4kUtQ9q4f70srHwQBWlZAQx+I1TB38l65kbB+rrxR/Kmd/m4ZRHUBbw2F8 JL5w3oM9A9LOKhUK2HOWPCdL71+5OvGw1gxDW7W9NT6OnyoXdSo6EM71nHrGeoId9eMvR0U ALDM3OnozEIjQ9A859uSH2w2sK2bZGGDhYXvmaPAUihLoYgvb2NvTksUoIgWkcDnemgXK3d V2DuXau+MA3lC1VCKxaT+iR7szVwImMW2JqWdFdfQn4niKlcuaWtOULg2B8Q== Received: from [10.12.239.196] (helo=localhost) by smtpcorp.com with esmtpsa (TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.99.1-S2G) (envelope-from ) id 1vvdub-AIkwcC8mKyv-HS7t; Thu, 26 Feb 2026 16:08:25 +0000 Date: Thu, 26 Feb 2026 16:49:31 +0100 From: Remi Pommarel To: Pablo MARTIN-GOMEZ Cc: Johannes Berg , linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH wireless] wifi: mac80211: Fix ADDBA update when HW supports reordering Message-ID: References: <5806bab7e46506d3c300ab4eb66989d42936aeb0.1771323902.git.repk@triplefau.lt> <6ed3a0ee5e15c73f304050d303e74441cdf61659.camel@sipsolutions.net> <0f0703e2749185f9a334b3435ffe247b42e6923b.camel@sipsolutions.net> <19061b55-a211-4448-8c49-ca8daa6d9d61@freebox.fr> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <19061b55-a211-4448-8c49-ca8daa6d9d61@freebox.fr> X-Report-Abuse: Please forward a copy of this message, including all headers, to Feedback-ID: 510616m:510616apGKSTK:510616sbru8S-D2W X-smtpcorp-track: 4Zq7CW2VfFRI.9U0juDLdwkyF.f1wSHACYO8y On Mon, Feb 23, 2026 at 02:25:13PM +0100, Pablo MARTIN-GOMEZ wrote: > Hello, > > On 23/02/2026 12:50, Johannes Berg wrote: > > On Sun, 2026-02-22 at 17:06 +0100, Remi Pommarel wrote: > >>>> That does make sense. However, if I understand correctly, it means that > >>>> even if we end up storing the timeout for drivers that support > >>>> reordering, a new IEEE80211_AMPDU_RX_UPDATE should still be introduced, > >>>> right? > >>> > >>> I guess in order to do a no-op update that doesn't change the timeout, > >>> we could? But not sure it's all worth it? > >> > >> I was going to say it would not be a no-op for a buf_size update but, > >> if I understand correctly, even when SUPPORTS_REORDERING_BUFFER is not > >> set the buf_size update is ignored completely and the reorder_buf is > >> not resized yet a successful addba response is sent. Don't we need to > >> check for buf_size change as well as timeout also? > > > > I was going to say that I thought buf_size is not allowed to change, but > > (re)reading the spec doesn't seem to bear that out. > For once, the standard (802.11-2024) is really clear on this (10.25.2): > > A block ack agreement may be modified by the originator by sending an > ADDBA Request frame (see 11.5.2, except that MLME-ADDBA primitives are > not used by the originator). All parameters of the agreement may be > modified except for the TID. If the request is not successful, the > existing agreement is not modified. If the request is successful, the > behavior is as if a DELBA frame for the block ack agreement had been > transmitted by the originator and received by the recipient immediately > prior to the ADDBA Request frame. > > > > I guess we could just unconditionally reject any updates. I'm not sure > > now why we ever added the update in the first place. Perhaps some > > implementation was doing no-op updates and failing on negative > > responses? > > > If the originator is compliant and trying to update, unconditionally > rejecing any update shouldn't have any side-effects. But if the > originator doesn't receive the ADDBA response, it is going to resend an > ADDBA request; for the originator, it is just a retry, but for the > recipient it's an update, so the originator is going to receive a non > success. And unless the originator sends a DELBA "by default" at some > point, it won't be able to create a new BA (for a given TID) with the > recipient. > [...] I’m a bit concerned that ignoring all ADDBA updates might break STAs with finicky aggregation implementations. For example, I’ve observed an ath12k mesh point get stuck in a loop, repeatedly sending the same ADDBA request (with unchanged timeout or buffer size) only for us to keep reject it each time. But I am, of course, unfortunately unable to reproduce that easily. -- Remi