From patchwork Thu Jun 4 07:32:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joyce Ooi X-Patchwork-Id: 1303334 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=intel.com Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49cyFr3gkkz9sSy for ; Thu, 4 Jun 2020 17:34:08 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728107AbgFDHeE (ORCPT ); Thu, 4 Jun 2020 03:34:04 -0400 Received: from mga04.intel.com ([192.55.52.120]:55247 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727105AbgFDHeD (ORCPT ); Thu, 4 Jun 2020 03:34:03 -0400 IronPort-SDR: TQEj41qzguCH0biOXjX29TkbAEWNGFi27RxTLnTSJPH+n1lYCOImRva1Ho/mEeEKoRnNxrUgKJ TqYMegs1n4Ow== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Jun 2020 00:34:02 -0700 IronPort-SDR: YIqGmvw6f0DRiTaGsg9vkTkLJQAgZbiirFFwXNy7lvmi0+yeYhRVZPtwegYdhwYad77V70nLEu iauv1no0zdVg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,471,1583222400"; d="scan'208";a="348021325" Received: from pg-nxl3.altera.com ([10.142.129.93]) by orsmga001.jf.intel.com with ESMTP; 04 Jun 2020 00:33:59 -0700 From: "Ooi, Joyce" To: Thor Thayer , "David S . Miller" , Jakub Kicinski Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Dalon Westergreen , Joyce Ooi , Tan Ley Foon , See Chin Liang , Dinh Nguyen , Dalon Westergreen Subject: [PATCH v3 01/10] net: eth: altera: tse_start_xmit ignores tx_buffer call response Date: Thu, 4 Jun 2020 15:32:47 +0800 Message-Id: <20200604073256.25702-2-joyce.ooi@intel.com> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20200604073256.25702-1-joyce.ooi@intel.com> References: <20200604073256.25702-1-joyce.ooi@intel.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Dalon Westergreen The return from tx_buffer call in tse_start_xmit is inapropriately ignored. tse_buffer calls should return 0 for success or NETDEV_TX_BUSY. tse_start_xmit should return not report a successful transmit when the tse_buffer call returns an error condition. In addition to the above, the msgdma and sgdma do not return the same value on success or failure. The sgdma_tx_buffer returned 0 on failure and a positive number of transmitted packets on success. Given that it only ever sends 1 packet, this made no sense. The msgdma implementation msgdma_tx_buffer returns 0 on success. -> Don't ignore the return from tse_buffer calls -> Fix sgdma tse_buffer call to return 0 on success and NETDEV_TX_BUSY on failure. Signed-off-by: Dalon Westergreen Signed-off-by: Joyce Ooi --- v2: no change v3: queue is stopped before returning NETDEV_TX_BUSY --- drivers/net/ethernet/altera/altera_sgdma.c | 19 ++++++++++++------- drivers/net/ethernet/altera/altera_tse_main.c | 4 +++- 2 files changed, 15 insertions(+), 8 deletions(-) diff --git a/drivers/net/ethernet/altera/altera_sgdma.c b/drivers/net/ethernet/altera/altera_sgdma.c index db97170da8c7..fe6276c7e4a3 100644 --- a/drivers/net/ethernet/altera/altera_sgdma.c +++ b/drivers/net/ethernet/altera/altera_sgdma.c @@ -4,6 +4,7 @@ */ #include +#include #include "altera_utils.h" #include "altera_tse.h" #include "altera_sgdmahw.h" @@ -159,10 +160,11 @@ void sgdma_clear_txirq(struct altera_tse_private *priv) SGDMA_CTRLREG_CLRINT); } -/* transmits buffer through SGDMA. Returns number of buffers - * transmitted, 0 if not possible. - * - * tx_lock is held by the caller +/* transmits buffer through SGDMA. + * original behavior returned the number of transmitted packets (always 1) & + * returned 0 on error. This differs from the msgdma. the calling function + * will now actually look at the code, so from now, 0 is good and return + * NETDEV_TX_BUSY when busy. */ int sgdma_tx_buffer(struct altera_tse_private *priv, struct tse_buffer *buffer) { @@ -173,8 +175,11 @@ int sgdma_tx_buffer(struct altera_tse_private *priv, struct tse_buffer *buffer) struct sgdma_descrip __iomem *ndesc = &descbase[1]; /* wait 'til the tx sgdma is ready for the next transmit request */ - if (sgdma_txbusy(priv)) - return 0; + if (sgdma_txbusy(priv)) { + if (!netif_queue_stopped(priv->dev)) + netif_stop_queue(priv->dev); + return NETDEV_TX_BUSY; + } sgdma_setup_descrip(cdesc, /* current descriptor */ ndesc, /* next descriptor */ @@ -191,7 +196,7 @@ int sgdma_tx_buffer(struct altera_tse_private *priv, struct tse_buffer *buffer) /* enqueue the request to the pending transmit queue */ queue_tx(priv, buffer); - return 1; + return 0; } diff --git a/drivers/net/ethernet/altera/altera_tse_main.c b/drivers/net/ethernet/altera/altera_tse_main.c index 1671c1f36691..2a9e6157a8a1 100644 --- a/drivers/net/ethernet/altera/altera_tse_main.c +++ b/drivers/net/ethernet/altera/altera_tse_main.c @@ -595,7 +595,9 @@ static int tse_start_xmit(struct sk_buff *skb, struct net_device *dev) buffer->dma_addr = dma_addr; buffer->len = nopaged_len; - priv->dmaops->tx_buffer(priv, buffer); + ret = priv->dmaops->tx_buffer(priv, buffer); + if (ret) + goto out; skb_tx_timestamp(skb);