From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dalon Westergreen Subject: [PATCH net-next 1/8] net: eth: altera: tse_start_xmit ignores tx_buffer call response Date: Wed, 14 Nov 2018 16:50:40 -0800 Message-ID: <20181115005047.28464-2-dwesterg@gmail.com> References: <20181115005047.28464-1-dwesterg@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: Dalon Westergreen To: netdev@vger.kernel.org, dinguyen@kernel.org, thor.thayer@linux.intel.com Return-path: Received: from mail-pg1-f194.google.com ([209.85.215.194]:45789 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725895AbeKOK4e (ORCPT ); Thu, 15 Nov 2018 05:56:34 -0500 Received: by mail-pg1-f194.google.com with SMTP id y4so8153713pgc.12 for ; Wed, 14 Nov 2018 16:50:58 -0800 (PST) In-Reply-To: <20181115005047.28464-1-dwesterg@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: 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 --- drivers/net/ethernet/altera/altera_sgdma.c | 14 ++++++++------ drivers/net/ethernet/altera/altera_tse_main.c | 4 +++- 2 files changed, 11 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/altera/altera_sgdma.c b/drivers/net/ethernet/altera/altera_sgdma.c index 88ef67a998b4..eb47b9b820bb 100644 --- a/drivers/net/ethernet/altera/altera_sgdma.c +++ b/drivers/net/ethernet/altera/altera_sgdma.c @@ -15,6 +15,7 @@ */ #include +#include #include "altera_utils.h" #include "altera_tse.h" #include "altera_sgdmahw.h" @@ -170,10 +171,11 @@ 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) { @@ -185,7 +187,7 @@ int sgdma_tx_buffer(struct altera_tse_private *priv, struct tse_buffer *buffer) /* wait 'til the tx sgdma is ready for the next transmit request */ if (sgdma_txbusy(priv)) - return 0; + return NETDEV_TX_BUSY; sgdma_setup_descrip(cdesc, /* current descriptor */ ndesc, /* next descriptor */ @@ -202,7 +204,7 @@ 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 baca8f704a45..dcb330129e23 100644 --- a/drivers/net/ethernet/altera/altera_tse_main.c +++ b/drivers/net/ethernet/altera/altera_tse_main.c @@ -606,7 +606,9 @@ 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); -- 2.19.1