From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-02.galae.net (smtpout-02.galae.net [185.246.84.56]) (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 4962543D4F4 for ; Mon, 3 Aug 2026 20:09:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.84.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785787771; cv=none; b=eyqtyIW76/yKmwUHWxczkBcYGgc+cr0mUgdZKHw4WKqUHiXpNzUNnzoL3BBz5+1mpO0nLO8zwRT9HpHhWLSeCOP8YYTCxOgYBDhuiKhcZe36lwrI4x3p+E9h1YEhUP4RJynPEBIpNC6RpghQz5oPKy01fByhnTjmBhiWT9KDfH4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785787771; c=relaxed/simple; bh=kE63NbFnByxwqx4KDQJD8hIDmeOEQJEON257mEvFJZ8=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=jr+Ye12SFhFYrCh2LJH/KorneApd9dJOQjewkwZX1LzULVsdg/a5p47vVdovHFnmJLjIBdjhh/EyeLuob9hgKS1Mz4+C5jj3ENbz9WY7yqM3MhbBSHwNZQQnZqSFbbDt2JcoHbwzc3dRsCwVZ9w7CSsLecDHvqQUERo4uZ/obc4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=LfEXPz2/; arc=none smtp.client-ip=185.246.84.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="LfEXPz2/" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-02.galae.net (Postfix) with ESMTPS id DF8411A13E0; Mon, 3 Aug 2026 20:09:28 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id A64306029B; Mon, 3 Aug 2026 20:09:28 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id E1D9611C3185D; Mon, 3 Aug 2026 22:09:25 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1785787767; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=oF+8Ic4uhloiWx9QzHDnP+pVsUx1IV5zRrauQ0Zmars=; b=LfEXPz2/nqujvE2s7lvqflQb0OXeWL7LiY8KZ5tUKzMOq6JJDv+ifRbgvDxx5gcKbnO2/U LAEM8GAGdmEWHLWpsjc5KuV5ZaZSBT5fXOiL2GmZvcOT4TbfwTM6LoezcDwFAM+qXA8Ej1 ABVHNZBFgRQvbEwzGr/RGKx0gs1fjPpe7ZbBHbVwiBUizBs+24MX3OYqinUTVaohvGNVQZ cwxfyCkjiASDDnKj3Jrc9L7/i+/Z4zLAQAk/qiV5Tr2iyqBxRDf/DiVQyzKbaElpROHZlz gq4grJUwCbdw8m+HYK6UVR8x5NpihXPuRo/v+ink04h80wSsrOGU1OlATzntEA== From: =?utf-8?q?Th=C3=A9o_Lebrun?= Date: Mon, 03 Aug 2026 22:08:24 +0200 Subject: [PATCH net-next v7 17/17] net: macb: use context swapping in .ndo_change_mtu() 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-Transfer-Encoding: 8bit Message-Id: <20260803-macb-context-v7-17-4d7d4af04849@bootlin.com> References: <20260803-macb-context-v7-0-4d7d4af04849@bootlin.com> In-Reply-To: <20260803-macb-context-v7-0-4d7d4af04849@bootlin.com> To: =?utf-8?q?Th=C3=A9o_Lebrun?= , Conor Dooley , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Richard Cochran , Russell King Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Nicolas Ferre , Claudiu Beznea , Paolo Valerio , Nicolai Buchwitz , Vladimir Kondratiev , Gregory CLEMENT , =?utf-8?q?Beno=C3=AEt_Monin?= , Tawfik Bayouk , Thomas Petazzoni , Maxime Chevallier X-Mailer: b4 0.15.2 X-Last-TLS-Session-Version: TLSv1.3 Use newly introduced context buffer management to implement .ndo_change_mtu() as a context swap: allocate new context -> reconfigure HW -> free old context. This resists memory pressure well by failing without closing the interface and it is much faster by avoiding PHY reinit. AT91 EMAC is handled differently as their buffer management is separate and they don't do NAPI. They cannot land in macb_change_mtu as they use a different ndo struct. We still defensively protect against it in code. Reviewed-by: Nicolai Buchwitz Signed-off-by: Théo Lebrun --- drivers/net/ethernet/cadence/macb_main.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c index 9093fb2c789f..df9594e515df 100644 --- a/drivers/net/ethernet/cadence/macb_main.c +++ b/drivers/net/ethernet/cadence/macb_main.c @@ -3531,11 +3531,29 @@ static int macb_close(struct net_device *netdev) static int macb_change_mtu(struct net_device *netdev, int new_mtu) { - if (netif_running(netdev)) - return -EBUSY; + struct macb *bp = netdev_priv(netdev); + bool running = netif_running(netdev); + struct macb_context *new_ctx; + + if (running) { + /* Context swapping is not supported for AT91. */ + if (bp->caps & MACB_CAPS_MACB_IS_EMAC) + return -EBUSY; + + new_ctx = macb_context_alloc(bp, new_mtu, + bp->configured_rx_ring_size, + bp->configured_tx_ring_size); + if (IS_ERR(new_ctx)) + return PTR_ERR(new_ctx); + + macb_context_swap_start(bp); + } WRITE_ONCE(netdev->mtu, new_mtu); + if (running) + macb_context_swap_end(bp, new_ctx); + return 0; } -- 2.55.0