From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from esa.microchip.iphmx.com (esa.microchip.iphmx.com [68.232.154.123]) (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 5788153E31C; Tue, 13 Oct 2026 19:49:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=68.232.154.123 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791920998; cv=none; b=NEePLXoNPw6gel2hzUPd3ZtusnkaK4qT+AfAaqV90Nj9eZRa9f5oiSoa8Zfc2zsXlI8SwZZOntkc/yuV2VFzilIhuCFXsQ/ag/AVVLwwwvGZNCYZ8guK3ro2GtrGwjIPHSO7aoq0wrlhjSW0rj1oKsxJgeZ2mKQZTOwNQYB6s5U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791920998; c=relaxed/simple; bh=lnPyQoJzvaAoTOXa9xWNkSRU6Wm8vtyKKtmMcFZ4Ogg=; h=Date:From:To:CC:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=TY8PBOVIztHNcceXH3TqPiDmkaXheIQbQgbnhCgcvhBCuf6uBQXEZk3psHncXK57rCh5yDmvE5HeMvzWnsqWCQLc+S+L5qDZ+iCZTRo1jWSLxPGekim6NbJr9g5HyRN6RKfKjePSH6vUboE47/N8oz1mL8ypMRaZ5OnB6Migv3M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=microchip.com; spf=pass smtp.mailfrom=microchip.com; dkim=pass (2048-bit key) header.d=microchip.com header.i=@microchip.com header.b=NiqQ/J/s; arc=none smtp.client-ip=68.232.154.123 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=microchip.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=microchip.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=microchip.com header.i=@microchip.com header.b="NiqQ/J/s" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1791920997; x=1823456997; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=lnPyQoJzvaAoTOXa9xWNkSRU6Wm8vtyKKtmMcFZ4Ogg=; b=NiqQ/J/si82jlF40MFcNVKoaFJB81cewBXsx4y70Z0VBAgFL1jiu61Nr FEwz/YtgcNcB+S+zsPQxXcCErNnlK8T8oK/SXWXEqOXYFOhzfrbqM/jWt K2oVB9BqwYV1GhEPqQ+Lgqu/4BHtaTjMtLrGHaYC6o51c9S5IMD6SeGAe LwioShNU8Gm2THUjXT9ZO+/fY+7pL0VyFHuhtbQn0lU5e1A25he4BvGV3 3xKYbB16iXVn8tRK1XiDXFwAOUs7eSYGsI8X6vnKmQPZ8ZFNKWqR5HUyb PH72BQzoEvtbNIJNza27SAkvJIOQgPYl7uXhvwTzA4klP0izDoh5NhN70 w==; X-CSE-ConnectionGUID: OxT+NZxtShudPuS1PDMCtQ== X-CSE-MsgGUID: Ry8g32UiRP2/6svSsJvEug== X-IronPort-AV: E=Sophos;i="6.27,156,1787036400"; d="scan'208";a="232072001" X-Amp-Result: SKIPPED(no attachment in message) Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa6.microchip.iphmx.com with ESMTP/TLS/ECDHE-RSA-AES128-GCM-SHA256; 13 Oct 2026 12:49:56 -0700 Received: from chn-vm-ex01.mchp-main.com (10.10.85.143) by chn-vm-ex02.mchp-main.com (10.10.85.144) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.58; Tue, 13 Oct 2026 12:49:55 -0700 Received: from DEN-DL-M70577 (10.10.85.11) by chn-vm-ex01.mchp-main.com (10.10.85.143) with Microsoft SMTP Server id 15.1.2507.58 via Frontend Transport; Tue, 13 Oct 2026 12:49:53 -0700 Date: Tue, 13 Oct 2026 21:49:52 +0200 From: Daniel Machon To: James Hilliard CC: , Paolo Abeni , Jakub Kicinski , Maxime Chevallier , Andrew Lunn , Eric Dumazet , Maxime Coquelin , Alexandre Torgue , Christian Marangi , "David S. Miller" , , , Nicolai Buchwitz Subject: Re: [PATCH net-next v2] net: stmmac: leave the datapath running for normal-size MTU changes Message-ID: <20261013194952.i7saki3p7zc2f2hm@DEN-DL-M70577> References: <20261013-stmmac-mtu-fastpath-v2-1-1e4ce8137689@gmail.com> 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="us-ascii" Content-Disposition: inline In-Reply-To: <20261013-stmmac-mtu-fastpath-v2-1-1e4ce8137689@gmail.com> > When both MTUs are at most ETH_DATA_LEN, the receive buffer size and MAC > receive limit do not change. Update the MTU without restarting the > datapath. > > This also avoids rebinding a live AF_XDP pool to a temporary RXQ. XDP > rejects jumbo MTUs, so all supported XDP MTU changes take this path. > Jumbo transitions still use the existing reopen path. > > Found by source review while working on the stmmac MTU/resume recovery > series. The fast path was tested on Allwinner H616 with sun8i EMAC1 and > an AC300 PHY. The AF_XDP scenario was identified by inspection. Reviewed-by: Daniel Machon