From patchwork Tue Feb 21 10:28:05 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Petazzoni X-Patchwork-Id: 730421 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3vSGvm5ZCDz9s7Z for ; Tue, 21 Feb 2017 21:29:40 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751997AbdBUK3j (ORCPT ); Tue, 21 Feb 2017 05:29:39 -0500 Received: from mail.free-electrons.com ([62.4.15.54]:49553 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751951AbdBUK3F (ORCPT ); Tue, 21 Feb 2017 05:29:05 -0500 Received: by mail.free-electrons.com (Postfix, from userid 110) id CA830207F3; Tue, 21 Feb 2017 11:28:47 +0100 (CET) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on mail.free-electrons.com X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED,SHORTCIRCUIT, URIBL_BLOCKED shortcircuit=ham autolearn=disabled version=3.4.0 Received: from localhost (LStLambert-657-1-97-87.w90-63.abo.wanadoo.fr [90.63.216.87]) by mail.free-electrons.com (Postfix) with ESMTPSA id E4FAE207F7; Tue, 21 Feb 2017 11:28:23 +0100 (CET) From: Thomas Petazzoni To: "David S. Miller" , netdev@vger.kernel.org Cc: Nadav Haklai , Hanna Hawa , Yehuda Yitschak , Jason Cooper , Andrew Lunn , Sebastian Hesselbarth , Gregory Clement , Russell King , Stefan Chulski , Thomas Petazzoni Subject: [PATCHv4 net-next 05/13] net: mvpp2: release reference to txq_cpu[] entry after unmapping Date: Tue, 21 Feb 2017 11:28:05 +0100 Message-Id: <1487672893-5746-6-git-send-email-thomas.petazzoni@free-electrons.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1487672893-5746-1-git-send-email-thomas.petazzoni@free-electrons.com> References: <1487672893-5746-1-git-send-email-thomas.petazzoni@free-electrons.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The mvpp2_txq_bufs_free() function is called upon TX completion to DMA unmap TX buffers, and free the corresponding SKBs. It gets the references to the SKB to free and the DMA buffer to unmap from a per-CPU txq_pcpu data structure. However, the code currently increments the pointer to the next entry before doing the DMA unmap and freeing the SKB. It does not cause any visible problem because for a given SKB the TX completion is guaranteed to take place on the CPU where the TX was started. However, it is much more logical to increment the pointer to the next entry once the current entry has been completely unmapped/released. Signed-off-by: Thomas Petazzoni Acked-by: Russell King --- drivers/net/ethernet/marvell/mvpp2.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/marvell/mvpp2.c b/drivers/net/ethernet/marvell/mvpp2.c index 6fe1520..b98c668d 100644 --- a/drivers/net/ethernet/marvell/mvpp2.c +++ b/drivers/net/ethernet/marvell/mvpp2.c @@ -4437,13 +4437,12 @@ static void mvpp2_txq_bufs_free(struct mvpp2_port *port, struct mvpp2_txq_pcpu_buf *tx_buf = txq_pcpu->buffs + txq_pcpu->txq_get_index; - mvpp2_txq_inc_get(txq_pcpu); - dma_unmap_single(port->dev->dev.parent, tx_buf->phys, tx_buf->size, DMA_TO_DEVICE); - if (!tx_buf->skb) - continue; - dev_kfree_skb_any(tx_buf->skb); + if (tx_buf->skb) + dev_kfree_skb_any(tx_buf->skb); + + mvpp2_txq_inc_get(txq_pcpu); } }