From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752546AbaB0X6I (ORCPT ); Thu, 27 Feb 2014 18:58:08 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:46804 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751224AbaB0X6F (ORCPT ); Thu, 27 Feb 2014 18:58:05 -0500 Message-ID: <1393545459.14067.79.camel@deadeye.wl.decadent.org.uk> Subject: Re: [PATCH v2 1/2] net: macb: Check DMA mappings for error From: Ben Hutchings To: Soren Brinkmann Cc: Nicolas Ferre , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Vinod Koul , Dan Williams , "David S. Miller" , Michal Simek Date: Thu, 27 Feb 2014 23:57:39 +0000 In-Reply-To: <1393538285-28297-1-git-send-email-soren.brinkmann@xilinx.com> References: <1393538285-28297-1-git-send-email-soren.brinkmann@xilinx.com> Content-Type: multipart/signed; micalg="pgp-sha512"; protocol="application/pgp-signature"; boundary="=-REnZseB9rYb9yHTq8IRs" X-Mailer: Evolution 3.8.5-2+b2 Mime-Version: 1.0 X-SA-Exim-Connect-IP: 82.132.232.167 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-REnZseB9rYb9yHTq8IRs Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, 2014-02-27 at 13:58 -0800, Soren Brinkmann wrote: [...] > diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/c= adence/macb.c > index 3190d38e16fb..a9c2ccfc1740 100644 > --- a/drivers/net/ethernet/cadence/macb.c > +++ b/drivers/net/ethernet/cadence/macb.c > @@ -632,11 +632,16 @@ static void gem_rx_refill(struct macb *bp) > "Unable to allocate sk_buff\n"); > break; > } > - bp->rx_skbuff[entry] =3D skb; > =20 > /* now fill corresponding descriptor entry */ > paddr =3D dma_map_single(&bp->pdev->dev, skb->data, > bp->rx_buffer_size, DMA_FROM_DEVICE); > + if (dma_mapping_error(&bp->pdev->dev, paddr)) { > + dev_kfree_skb(skb); > + break; > + } > + > + bp->rx_skbuff[entry] =3D skb; > =20 > if (entry =3D=3D RX_RING_SIZE - 1) > paddr |=3D MACB_BIT(RX_WRAP); > @@ -1040,6 +1045,10 @@ static int macb_start_xmit(struct sk_buff *skb, st= ruct net_device *dev) A bit more context: entry =3D macb_tx_ring_wrap(bp->tx_head); bp->tx_head++; > netdev_vdbg(bp->dev, "Allocated ring entry %u\n", entry); > mapping =3D dma_map_single(&bp->pdev->dev, skb->data, > len, DMA_TO_DEVICE); > + if (dma_mapping_error(&bp->pdev->dev, mapping)) { > + kfree_skb(skb); > + goto unlock; > + } You need to move the bp->tx_head increment below this error check. Sorry I didn't spot this the first time. Ben. > tx_skb =3D &bp->tx_skb[entry]; > tx_skb->skb =3D skb; > @@ -1066,6 +1075,7 @@ static int macb_start_xmit(struct sk_buff *skb, str= uct net_device *dev) > if (CIRC_SPACE(bp->tx_head, bp->tx_tail, TX_RING_SIZE) < 1) > netif_stop_queue(dev); > =20 > +unlock: > spin_unlock_irqrestore(&bp->lock, flags); > =20 > return NETDEV_TX_OK; --=20 Ben Hutchings It is easier to change the specification to fit the program than vice versa= . --=-REnZseB9rYb9yHTq8IRs Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIVAwUAUw/Q8+e/yOyVhhEJAQqywg/+Ivi3z8MWimM6uUBsqbXLLIujaQGiu6Y+ b7rI3fljaIhAV9PFgurc4wcxtoYlXKZG8mWjWUdwwIeOZqLhO9fryqf9U4DvKLr8 uM0Oua2Aa7E2EGa8U5CMIU6DVRJ3w0/0WqaBv1ERCE9dhUKJqq4uK2S69VKmlt9N QwdMgFHc0cj2x8xRPZKbpHqlOlzvajUYlZCSYkS3ZNE+BvNumZCwH0qzumfcX0Yg PvH55qwDnCDbhPP69h7yn7fpXHiKuiF3gAF64vcM3T3L7TDNDoQNe6kvqIk5obSY WBMfsBSfbZtrSn44gfQzHnSJe5se8Zhs2GWCnXBMWPXNQDWpwFcRZKje1JS9PdqY a+stuXFnU5h87NmknyzPnxysQP7PWGx5gWwfD/GxFQQlzDISgQf/OBvmGFiM1IKf M77XpvgfJKkBZPiE/BavXzu/PYreMdl0GsFvz9hddWqpOh9dBL/rAx4ePt93/x+o cQ+nqGU07e8CLaGhqoMAF3LUr2CYzTe1Lcbr6T3Cs3bNxfEdW+e5mGV/bOTEI2p4 5oWOkhrLVIljQnA29vTISfKQ1dbTtweOiLqOhwDeSnZa3VX9SpgRieqiP5Rqz/9Z 53kGqy5CP1FGAI/bAuMWPhHMzg8FXlmNmXfyUM9VfR701yPXPsEepkydnGpYPUaG FAGjmDCD+mA= =cG6d -----END PGP SIGNATURE----- --=-REnZseB9rYb9yHTq8IRs--