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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4F837C433EF for ; Sun, 5 Dec 2021 13:39:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234191AbhLENml (ORCPT ); Sun, 5 Dec 2021 08:42:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52552 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234166AbhLENml (ORCPT ); Sun, 5 Dec 2021 08:42:41 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D5BEEC061714 for ; Sun, 5 Dec 2021 05:39:13 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 9D515B80E18 for ; Sun, 5 Dec 2021 13:39:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BB6D6C341C5; Sun, 5 Dec 2021 13:39:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1638711551; bh=HsH047zFhqksN7/fNRMNRwpVvXoqvDfmCLkqmklt7Aw=; h=Subject:To:Cc:From:Date:From; b=twObPNmmQJaYekMI53KjiXVgU7rzYA18sB0Lq8hMlITkhu5zGP18zR/0ze6L99wlA Lhp0beMk75qHPRqu4QI+8pqgMzZFTc8T4GfRBmcBLTpx8texTfsF2JyrT5BLRa19/L mNIYVZgUgnMnrQTr3NmO2N9ck/jQ23J3wTptCk3E= Subject: FAILED: patch "[PATCH] net: stmmac: Avoid DMA_CHAN_CONTROL write if no Split Header" failed to apply to 5.10-stable tree To: vincent.whitchurch@axis.com, davem@davemloft.net Cc: From: Date: Sun, 05 Dec 2021 14:39:08 +0100 Message-ID: <1638711548199241@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From f8e7dfd6fdabb831846ab1970a875746559d491b Mon Sep 17 00:00:00 2001 From: Vincent Whitchurch Date: Fri, 26 Nov 2021 16:51:15 +0100 Subject: [PATCH] net: stmmac: Avoid DMA_CHAN_CONTROL write if no Split Header support The driver assumes that split headers can be enabled/disabled without stopping/starting the device, so it writes DMA_CHAN_CONTROL from stmmac_set_features(). However, on my system (IP v5.10a without Split Header support), simply writing DMA_CHAN_CONTROL when DMA is running (for example, with the commands below) leads to a TX watchdog timeout. host$ socat TCP-LISTEN:1024,fork,reuseaddr - & device$ ethtool -K eth0 tso off device$ ethtool -K eth0 tso on device$ dd if=/dev/zero bs=1M count=10 | socat - TCP4:host:1024 Note that since my IP is configured without Split Header support, the driver always just reads and writes the same value to the DMA_CHAN_CONTROL register. I don't have access to any platforms with Split Header support so I don't know if these writes to the DMA_CHAN_CONTROL while DMA is running actually work properly on such systems. I could not find anything in the databook that says that DMA_CHAN_CONTROL should not be written when the DMA is running. But on systems without Split Header support, there is in any case no need to call enable_sph() in stmmac_set_features() at all since SPH can never be toggled, so we can avoid the watchdog timeout there by skipping this call. Fixes: 8c6fc097a2f4acf ("net: stmmac: gmac4+: Add Split Header support") Signed-off-by: Vincent Whitchurch Signed-off-by: David S. Miller diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 748195697e5a..da8306f60730 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -5540,8 +5540,6 @@ static int stmmac_set_features(struct net_device *netdev, netdev_features_t features) { struct stmmac_priv *priv = netdev_priv(netdev); - bool sph_en; - u32 chan; /* Keep the COE Type in case of csum is supporting */ if (features & NETIF_F_RXCSUM) @@ -5553,10 +5551,13 @@ static int stmmac_set_features(struct net_device *netdev, */ stmmac_rx_ipc(priv, priv->hw); - sph_en = (priv->hw->rx_csum > 0) && priv->sph; + if (priv->sph_cap) { + bool sph_en = (priv->hw->rx_csum > 0) && priv->sph; + u32 chan; - for (chan = 0; chan < priv->plat->rx_queues_to_use; chan++) - stmmac_enable_sph(priv, priv->ioaddr, sph_en, chan); + for (chan = 0; chan < priv->plat->rx_queues_to_use; chan++) + stmmac_enable_sph(priv, priv->ioaddr, sph_en, chan); + } return 0; }