From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A4BFCC79FBF for ; Thu, 10 Sep 2026 18:14:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:Message-ID:References:In-Reply-To:Subject:Cc:To:From:Date: MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=gTba1NzUG5xbAP4x+gUk6us1Ud5EI0aPxbPupazDE+E=; b=AsOm1h1soop5SAfpQzs4Yxzh77 skxDBFWSCvFYvxlmIhg84DsncOSCfg/6zEWFjms6mnzLiejwtL8gGBlINbIsVbVeh0S9qvF0QL1+M iZHrQAG2Twpk34juFAA+boBThMYiz8XUEnRJ4LENSBFllfQqlJUWCS4i0cRod34zSIh/YJNCrE9FA 6dlOugNBuf1SnYWyjcc8P3oqltueN40Hsn0DCGc943ZPlFvh2CNck7iNptxSOk4swgVcVKKXPNOlN vakG3r98kltO5+DcD6z4ikatsWsRoKByB7d5D/h7Nlc31EZFjhbMtxIeblWsaD/9QvYAPoXMEqtcI HsD8w85Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x4jHY-0000000F8Fd-1LCu; Thu, 10 Sep 2026 18:13:56 +0000 Received: from mail.tipi-net.de ([194.13.80.246]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x4jHV-0000000F8EO-2pOc for linux-arm-kernel@lists.infradead.org; Thu, 10 Sep 2026 18:13:54 +0000 Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 7832FA0580; Thu, 10 Sep 2026 20:13:50 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tipi-net.de; s=dkim; t=1789064031; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=gTba1NzUG5xbAP4x+gUk6us1Ud5EI0aPxbPupazDE+E=; b=3a+j74DPcEdAczUXBJ2bDGgzvEK5RyO+Ay2DOQr7R33QufMvsp0nffsp1zBVquSVDnGc5J TyUU2qWlioSFDGm8grYtMTRTx4Z7FJi0MHY7SozgArH83dIq4qLNIQJ4TTeUnVLhCuuEu3 umKNP+Wj1eWVFll8NeAzku9iC5S2fqB/tREeCLzXAd/OL0UXxUyuo1y1y7AvaLrSfy9ecr MnfBY70d5ciTr5nZcygs98uzPqgKsZbFySqcYqC32OM08pa4hN2lwPY2wjnnUStUIHDMDC WHend6RCCH8FZeXtDesIMK7JWPYMYZiGJnoF5CLy7pwMz432k+8WS7l2GKosjA== MIME-Version: 1.0 Date: Thu, 10 Sep 2026 20:13:50 +0200 From: Nicolai Buchwitz To: Maxime Chevallier Cc: Andrew Lunn , davem@davemloft.net, Eric Dumazet , Jakub Kicinski , Paolo Abeni , Russell King , Heiner Kallweit , =?UTF-8?Q?Alexis_Lothor=C3=A9?= , Maxime Coquelin , Alexandre Torgue , Emil Renner Berthing , Minda Chen , Neil Armstrong , Kevin Hilman , Jerome Brunet , Martin Blumenstingl , Jan Petrous , Ovidiu Panait , Jose.Abreu@synopsys.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, thomas.petazzoni@bootlin.com, linux-arm-kernel@lists.infradead.org, linux-stm32@st-md-mailman.stormreply.com, PKneuper@dspace.de, David Laight Subject: Re: [PATCH net v2 6/6] net: stmmac: selftests: Account for alignment shift on dwmac1000 for Jumbo test In-Reply-To: <20260910151404.976753-7-maxime.chevallier@bootlin.com> References: <20260910151404.976753-1-maxime.chevallier@bootlin.com> <20260910151404.976753-7-maxime.chevallier@bootlin.com> Message-ID: <999537422e65948cc80714942b3d152a@tipi-net.de> X-Sender: nb@tipi-net.de Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit X-Last-TLS-Session-Version: TLSv1.3 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260910_111353_912952_D81AD8B2 X-CRM114-Status: GOOD ( 17.63 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 10.9.2026 17:14, Maxime Chevallier wrote: > On dwmac1000, we currently only support single-descriptor frames. The > Jumbo test started failing when NET_IP_ALIGN was added to align the IP > header, as this tests tries to send the biggest possible frame. > > On dwmac1000 the DMA transfer is aligned on 4-bytes, so adding a 2-byte > shift at the start-of-buffer address means it takes a whole extra > 4-byte > DMA burst to receive the Jumbo packet, causing it to spill over the > next > descriptor. > > This doesn't seem to happen on dwmac4 and xgmac that appear to > correctly > handle unaligned xfers (only tested on dwmac4) > > Let's account for that in the Jumbo test, reduce the size of our big > packet by the align size. > > Fixes: 23680bf5f8c6 ("net: stmmac: restore NET_IP_ALIGN in the RX DMA > offset") > Signed-off-by: Maxime Chevallier > --- > drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c > b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c > index ec56ee0031ab..fc8d69260f43 100644 > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c > @@ -1776,6 +1776,9 @@ static int __stmmac_test_jumbo(struct stmmac_priv > *priv, u16 queue) > struct stmmac_packet_attrs attr = { }; > int size = priv->dma_conf.dma_buf_sz; > > + if (!dwmac_is_xmac(priv->plat->core_type)) > + size -= NET_IP_ALIGN; > + > attr.dst = priv->dev->dev_addr; > attr.max_size = size - ETH_FCS_LEN; > attr.queue_mapping = queue; Reviewed-by: Nicolai Buchwitz Thanks, Nicolai