From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: Re: [RFC/RFT] forcedeth: Fix 'device driver failed to check map error' warnings Date: Fri, 28 Dec 2012 12:57:40 +0100 Message-ID: <1356695860.17740.51.camel@deadeye.wl.decadent.org.uk> References: <50db61fe.u8zB6nsB1I7ajQXN%Larry.Finger@lwfinger.net> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: , , To: Larry Finger Return-path: In-Reply-To: <50db61fe.u8zB6nsB1I7ajQXN%Larry.Finger@lwfinger.net> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Wed, 2012-12-26 at 14:45 -0600, Larry Finger wrote: > With 3.8-rc1, there are WARNINGS that the driver is not checking for > DMA mapping errors. The warnings start with > > ------------[ cut here ]------------ > WARNING: at lib/dma-debug.c:933 check_unmap+0x480/0x950() > Hardware name: HP Pavilion dv2700 Notebook PC > forcedeth 0000:00:0a.0: DMA-API: device driver failed to check > map error[device address=0x00000000b176e002] [size=90 bytes] [mapped as single] > > Signed-off-by: Larry Finger > --- > > Please check that the error returns are correctly done. [...] > @@ -2217,6 +2229,9 @@ static netdev_tx_t nv_start_xmit(struct > bcnt = (size > NV_TX2_TSO_MAX_SIZE) ? NV_TX2_TSO_MAX_SIZE : size; > np->put_tx_ctx->dma = pci_map_single(np->pci_dev, skb->data + offset, bcnt, > PCI_DMA_TODEVICE); > + if (pci_dma_mapping_error(np->pci_dev, > + np->put_tx_ctx->dma)) > + return NETDEV_TX_BUSY; > np->put_tx_ctx->dma_len = bcnt; > np->put_tx_ctx->dma_single = 1; > put_tx->buf = cpu_to_le32(np->put_tx_ctx->dma); > @@ -2337,6 +2352,9 @@ static netdev_tx_t nv_start_xmit_optimiz > bcnt = (size > NV_TX2_TSO_MAX_SIZE) ? NV_TX2_TSO_MAX_SIZE : size; > np->put_tx_ctx->dma = pci_map_single(np->pci_dev, skb->data + offset, bcnt, > PCI_DMA_TODEVICE); > + if (pci_dma_mapping_error(np->pci_dev, > + np->put_tx_ctx->dma)) > + return NETDEV_TX_BUSY; > np->put_tx_ctx->dma_len = bcnt; > np->put_tx_ctx->dma_single = 1; > put_tx->bufhigh = cpu_to_le32(dma_high(np->put_tx_ctx->dma)); [...] In these cases the skb should be freed and the return value should be NETDEV_TX_OK. Ben. -- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked.