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 00C65426EDC for ; Thu, 26 Feb 2026 16:23:37 +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=1772123019; cv=none; b=iAiRAoG1ThQlB1cHKxC2MdNJ7tXOKXy8rw/1clJH3Kd2iKuLG1NqUa3jZ7wF30FdOf/33cT6cezEPQWv0hpOM9j0TBVPLsV/9m7VwJ1aPvMiedmrk2q2zy+/Q90fuW8jZigzSinFNMSPQYuep7EgNMFCaG5Yo0ilOzxRIspwJqo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772123019; 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=nXjslhnvt9pkZkM6z+udKKeC0gBjLgQRkKwNqI1tcGVIj4909R0+7KbnYjvyMOldX+uqnZQQi0MsH8WaTu1PNIOve6SvQLVhfLUenQxx0E2MrgJLSggTeB2uQkpgRrlg+F8yB+s995aTyKTp6AlKhS+pnSb6HyQX09gu6jkl5aA= 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=lzwJm0tb; 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="lzwJm0tb" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=triplefau.lt; i=@triplefau.lt; q=dns/txt; s=s510616; t=1772122108; h=from : subject : to : message-id : date; bh=lzPuixvWghzNpH0Uka8bHYTOqSCBdAw6KoT3MIt+FGg=; b=lzwJm0tbya3yKpnXn6VJiHIrVuLpp0LHtmFzfvyt+vKHcISHzrR4V+oTkKPJ/EmVBp2fv hLh3lx0NjvvMpTvDmrNQgt4NN4tFu74ILa2MEJQsM6HPOlICg/DxV4yT4ueayr8vAlvcZah opEsDYvf86gGtPad8suyOdAizsqNbpt4WOzR9du8zKk023AzbfRT9yGRGjIWFwDzNJDAX1y MapCgI8LACaARuemcqDDbAA0XFNFkJ3iGz0aSySY6Ud14yoTpsjhj02FcrvVkG57WIiv9tj wXAwd2jbmAB78/xyNF5CSl5cCWh+Bnuu0KZVXkNph9hyF6x6Er6ncOouNMlQ== 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-wireless@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: nUy9xRlBd2r3.T2VmRAQcviVA.l8N8swOZyRD 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