From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756908AbdJKAr4 (ORCPT ); Tue, 10 Oct 2017 20:47:56 -0400 Received: from omzsmtpe01.verizonbusiness.com ([199.249.25.210]:18655 "EHLO omzsmtpe01.verizonbusiness.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756852AbdJKArr (ORCPT ); Tue, 10 Oct 2017 20:47:47 -0400 From: "Levin, Alexander (Sasha Levin)" X-Host: endeavour.tdc.vzwcorp.com To: "gregkh@linuxfoundation.org" CC: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [GIT PULL for-4.4 18/25] net: mvpp2: release reference to txq_cpu[] entry after unmapping Thread-Topic: [GIT PULL for-4.4 18/25] net: mvpp2: release reference to txq_cpu[] entry after unmapping Thread-Index: AQHTQipE7eZcaEXLpEuBMaiulg4wfA== Date: Wed, 11 Oct 2017 00:45:42 +0000 Message-ID: <20171011004533.8044-19-alexander.levin@verizon.com> References: <20171011004533.8044-1-alexander.levin@verizon.com> In-Reply-To: <20171011004533.8044-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id v9B0mPwX029970 From: Thomas Petazzoni [ Upstream commit 36fb7435b6ac4d288a2d4deea8934f9456ab46b6 ] 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 Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- 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 0e67145bc418..4f34e1b79705 100644 --- a/drivers/net/ethernet/marvell/mvpp2.c +++ b/drivers/net/ethernet/marvell/mvpp2.c @@ -4415,13 +4415,12 @@ 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); } } -- 2.11.0