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 D06A14A33FC for ; Wed, 1 Jul 2026 15:59:55 +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=1782921597; cv=none; b=UzoWLf8fccO8VAL8luQihjuRYNO9IZswaxR51N16Uma9mFLMIrGuQ2b8GHgRTh7zz6ROk39YbjVPK3uxQsQHPDNJiKWTeN3XzgayZvRGS+PsvzcSohOzff1yveK9txTrtkptLaVkT2lCyCuUV6ti32MrEPVgTnqEmbJgyF77AzU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782921597; c=relaxed/simple; bh=imh7P0JTaVWRePvYGzE8FfydCVrHiFYQpcF41od36MA=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=WJd+GUN4L3FOmj+njJ8u/ZDL5FDQsv9CivAOrNVkhf6HRUOr9GoWUsARlaDJBAvQEv9ZKK9m1ZL0Oa4mDbBVasGvP7iZYCguhT6gtmVkDDhdW5oAXs63iEdtlsBweF3rWb1/R2fkXM9G4kavP2CZW9c63Ye0tYew7zi1fmuDwDs= 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=xRACJjph; 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="xRACJjph" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-02.galae.net (Postfix) with ESMTPS id 829EB1A0DC1; Wed, 1 Jul 2026 15:59:54 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 5541260288; Wed, 1 Jul 2026 15:59:54 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 489A1104C9685; Wed, 1 Jul 2026 17:59:51 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1782921593; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=qsCflLJ4qD61g9gZCgzfH4uaFSkKAlJYV53mm/t6gxo=; b=xRACJjphTJV11NvG5dHuI8kxRbkyCu83HgCdHXllBm6FainXsVHnHK/mDx3+6duETzMeBO J5PybSQin7pLUDxKyIS90meuckG5HOK2tNotuwe5XCMSDUueD1n0iv2Ix3wZHWXYISqyWC BzU1qLDb3lumCqdnrQbwTIO0EZa8m4ZOmiiw1mdsrxrrpsmj8aG8+EBGcooe3eM6IvkUiP YpuxNzmvRwYzAs655s6uOwqRAktdJUgF+4saCSuiOwie1kdsp/aLdRVb0U77yN9+d8hh6r kF1HBsbwDBBCXUKbVjrRLKYmaB3SSRkQwwB6RWf9aseSVjb6WItGJPu4vXt6JQ== From: =?utf-8?q?Th=C3=A9o_Lebrun?= Date: Wed, 01 Jul 2026 17:59:18 +0200 Subject: [PATCH net-next v3 15/15] net: macb: use context swapping in .ndo_change_mtu() Precedence: bulk X-Mailing-List: netdev@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: <20260701-macb-context-v3-15-00268d5b1502@bootlin.com> References: <20260701-macb-context-v3-0-00268d5b1502@bootlin.com> In-Reply-To: <20260701-macb-context-v3-0-00268d5b1502@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. We refuse them (-EBUSY) to avoid implementing context swapping for them. 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 f0241ade1beb..0ea7123ec8f8 100644 --- a/drivers/net/ethernet/cadence/macb_main.c +++ b/drivers/net/ethernet/cadence/macb_main.c @@ -3467,11 +3467,29 @@ 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