From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 ED970746F for ; Sun, 17 Sep 2023 20:38:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 57EC0C433CA; Sun, 17 Sep 2023 20:38:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694983133; bh=moRk88YUu6uK9aPCDL9/S4gDJr9F8E2HPP8Zm2wGP1E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gcPKcKgZDZzKe4KXP3F9NsjSl7G9vQMT4p6MCdnufXbCvUo18zdnDhE/T0RpWmBpR no3wpjYR3MaLmxfu26Nr1kbpe+Ho7pKcmYZKEyfMidzaJZPpgi2nJTIufdZ8iqz3TM ki5MN+WrXcMQLwNDFLu3mK/yU35f4OSDHEQB4IlI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Vladimir Oltean , "David S. Miller" , Sasha Levin Subject: [PATCH 5.15 453/511] net: dsa: sja1105: fix -ENOSPC when replacing the same tc-cbs too many times Date: Sun, 17 Sep 2023 21:14:40 +0200 Message-ID: <20230917191124.698259110@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230917191113.831992765@linuxfoundation.org> References: <20230917191113.831992765@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vladimir Oltean [ Upstream commit 894cafc5c62ccced758077bd4e970dc714c42637 ] After running command [2] too many times in a row: [1] $ tc qdisc add dev sw2p0 root handle 1: mqprio num_tc 8 \ map 0 1 2 3 4 5 6 7 queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 hw 0 [2] $ tc qdisc replace dev sw2p0 parent 1:1 cbs offload 1 \ idleslope 120000 sendslope -880000 locredit -1320 hicredit 180 (aka more than priv->info->num_cbs_shapers times) we start seeing the following error message: Error: Specified device failed to setup cbs hardware offload. This comes from the fact that ndo_setup_tc(TC_SETUP_QDISC_CBS) presents the same API for the qdisc create and replace cases, and the sja1105 driver fails to distinguish between the 2. Thus, it always thinks that it must allocate the same shaper for a {port, queue} pair, when it may instead have to replace an existing one. Fixes: 4d7525085a9b ("net: dsa: sja1105: offload the Credit-Based Shaper qdisc") Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/dsa/sja1105/sja1105_main.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) diff --git a/drivers/net/dsa/sja1105/sja1105_main.c b/drivers/net/dsa/sja1105/sja1105_main.c index 5f70773fa8201..9176bd78b3d61 100644 --- a/drivers/net/dsa/sja1105/sja1105_main.c +++ b/drivers/net/dsa/sja1105/sja1105_main.c @@ -2015,6 +2015,18 @@ static void sja1105_bridge_leave(struct dsa_switch *ds, int port, #define BYTES_PER_KBIT (1000LL / 8) +static int sja1105_find_cbs_shaper(struct sja1105_private *priv, + int port, int prio) +{ + int i; + + for (i = 0; i < priv->info->num_cbs_shapers; i++) + if (priv->cbs[i].port == port && priv->cbs[i].prio == prio) + return i; + + return -1; +} + static int sja1105_find_unused_cbs_shaper(struct sja1105_private *priv) { int i; @@ -2055,9 +2067,14 @@ static int sja1105_setup_tc_cbs(struct dsa_switch *ds, int port, if (!offload->enable) return sja1105_delete_cbs_shaper(priv, port, offload->queue); - index = sja1105_find_unused_cbs_shaper(priv); - if (index < 0) - return -ENOSPC; + /* The user may be replacing an existing shaper */ + index = sja1105_find_cbs_shaper(priv, port, offload->queue); + if (index < 0) { + /* That isn't the case - see if we can allocate a new one */ + index = sja1105_find_unused_cbs_shaper(priv); + if (index < 0) + return -ENOSPC; + } cbs = &priv->cbs[index]; cbs->port = port; -- 2.40.1