Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752622AbaLEMmL (ORCPT ); Fri, 5 Dec 2014 07:42:11 -0500 Received: from mail-yk0-f182.google.com ([209.85.160.182]:37221 "EHLO mail-yk0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751141AbaLEMmJ (ORCPT ); Fri, 5 Dec 2014 07:42:09 -0500 MIME-Version: 1.0 X-Originating-IP: [77.108.99.98] In-Reply-To: <1417775874-17775-3-git-send-email-asolokha@kb.kras.ru> References: <1417775874-17775-1-git-send-email-asolokha@kb.kras.ru> <1417775874-17775-3-git-send-email-asolokha@kb.kras.ru> Date: Fri, 5 Dec 2014 16:42:08 +0400 Message-ID: Subject: Re: [PATCH 2/2] gianfar: handle map error in gfar_start_xmit() From: Denis Kirjanov To: Arseny Solokha Cc: Claudiu Manoil , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/5/14, Arseny Solokha wrote: > From: Arseny Solokha > > When DMA-API debugging is enabled in the kernel, it spews the following > upon upping the link: > > WARNING: at lib/dma-debug.c:1135 > Modules linked in: > CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W O 3.18.0-rc7 #1 > task: c0720340 ti: effe2000 task.ti: c0750000 > NIP: c01d7c1c LR: c01d7c1c CTR: c02250fc > REGS: effe3d40 TRAP: 0700 Tainted: G W O (3.18.0-rc7) > MSR: 00021000 CR: 22044242 XER: 20000000 > > GPR00: c01d7c1c effe3df0 c0720340 00000095 c201e404 c201e9f0 00021000 > 01a9d000 > GPR08: 00000007 00000000 01a9d000 00000313 22044242 00583f60 05f41012 > 00000000 > GPR16: 00000000 000000ff 00000000 00000000 00000000 c5dc3b40 c5677720 > 00000001 > GPR24: c0730000 00029000 c0d0d828 c072c394 effe3e48 c075baec c0d0f020 > ee31e600 > NIP [c01d7c1c] check_unmap+0x5b4/0xae4 > LR [c01d7c1c] check_unmap+0x5b4/0xae4 > Call Trace: > [effe3df0] [c01d7c1c] check_unmap+0x5b4/0xae4 (unreliable) > [effe3e40] [c01d81c4] debug_dma_unmap_page+0x78/0x8c > [effe3ec0] [c0286ba0] gfar_clean_tx_ring+0x120/0x3c0 > [effe3f30] [c0286f90] gfar_poll_tx_sq+0x48/0x94 > o[effe3f50] [c030c388] net_rx_action+0x130/0x1ac > [effe3f80] [c00319e0] __do_softirq+0x134/0x240 > [effe3fe0] [c0031dd0] irq_exit+0xa4/0xc8 > [effe3ff0] [c000e01c] call_do_irq+0x24/0x3c > [c0751e70] [c0004a04] do_IRQ+0x8c/0x108 > [c0751e90] [c0010068] ret_from_except+0x0/0x18 > --- interrupt: 501 at arch_cpu_idle+0x24/0x5c > LR = arch_cpu_idle+0x24/0x5c > [c0751f50] [c007d2e4] rcu_idle_enter+0xc8/0xcc (unreliable) > [c0751f60] [c006587c] cpu_startup_entry+0x1d4/0x29c > [c0751fb0] [c054399c] start_kernel+0x338/0x34c > [c0751ff0] [c000046c] set_ivor+0x154/0x190 > Instruction dump: > 394adb30 80fc0018 811c001c 3c60c04f 5529103a 7cca482e 38639e60 813c0020 > 815c0024 90c10008 4cc63182 48240b01 <0fe00000> 3c60c04f 3863971c 4cc63182 > ---[ end trace 3eb7bf62ba1b80f9 ]--- > Mapped at: > [] gfar_start_xmit+0x424/0x910 > [] dev_hard_start_xmit+0x20c/0x3d8 > [] sch_direct_xmit+0x124/0x22c > [] __dev_queue_xmit+0x2b8/0x674 > > Or the following upon starting transmission of some large chunks > of data: > > fsl-gianfar ffe25000.ethernet: DMA-API: device driver failed to check map > error[device address=0x0000000005fa8000] > ------------[ cut here ]------------ > WARNING: at lib/dma-debug.c:1135 > Modules linked in: > CPU: 0 PID: 0 Comm: swapper/0 Tainted: G O 3.18.0-rc7 #35 > task: c071d340 ti: effe2000 task.ti: c074e000 > NIP: c01d7c1c LR: c01d7c1c CTR: c022339c > REGS: effe3d40 TRAP: 0700 Tainted: G O (3.18.0-rc7) > MSR: 00021000 CR: 22044242 XER: 20000000 > > GPR00: c01d7c1c effe3df0 c071d340 00000094 00000001 c0071750 00000000 > 00000001 > GPR08: 00000000 00000000 effe2000 00000000 20044242 00581f60 05fa8000 > 000001c4 > GPR16: 00000000 000000ff 00000000 000000e4 00000039 c5b1a9c0 c5679c60 > 00000002 > GPR24: c0730000 00029000 c0d0c528 c0729394 effe3e48 c0759aec c0d0d020 > ee315900 > NIP [c01d7c1c] check_unmap+0x5b4/0xae4 > LR [c01d7c1c] check_unmap+0x5b4/0xae4 > Call Trace: > [effe3df0] [c01d7c1c] check_unmap+0x5b4/0xae4 (unreliable) > [effe3e40] [c01d81c4] debug_dma_unmap_page+0x78/0x8c > [effe3ec0] [c0284c78] gfar_clean_tx_ring+0x1b4/0x3c0 > [effe3f30] [c0284fd4] gfar_poll_tx_sq+0x48/0x94 > [effe3f50] [c030a5c4] net_rx_action+0x130/0x1ac > [effe3f80] [c00319e0] __do_softirq+0x134/0x240 > [effe3fe0] [c0031dd0] irq_exit+0xa4/0xc8 > [effe3ff0] [c000e01c] call_do_irq+0x24/0x3c > [c074fe70] [c0004a04] do_IRQ+0x8c/0x108 > [c074fe90] [c0010068] ret_from_except+0x0/0x18 > --- interrupt: 501 at arch_cpu_idle+0x24/0x5c > LR = arch_cpu_idle+0x24/0x5c > [c074ff50] [c007d2e4] rcu_idle_enter+0xc8/0xcc (unreliable) > [c074ff60] [c006587c] cpu_startup_entry+0x1d4/0x29c > [c074ffb0] [c054199c] start_kernel+0x338/0x34c > [c074fff0] [c000046c] set_ivor+0x154/0x190 > Instruction dump: > 394abb30 80fc0018 811c001c 3c60c04e 5529103a 7cca482e 386379f0 813c0020 > 815c0024 90c10008 4cc63182 4823ed39 <0fe00000> 3c60c04e 386372ac 4cc63182 > ---[ end trace 008c59ca7ca1f712 ]--- > Mapped at: > [] gfar_start_xmit+0x224/0x95c > [] dev_hard_start_xmit+0x20c/0x3d8 > [] sch_direct_xmit+0x124/0x22c > [] __qdisc_run+0x88/0x1c0 > [] net_tx_action+0xf0/0x19c > > Ignore these mapping failures in hope we'll have more luck next time. > > Signed-off-by: Arseny Solokha > --- > drivers/net/ethernet/freescale/gianfar.c | 17 +++++++++++++++-- > 1 file changed, 15 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/ethernet/freescale/gianfar.c > b/drivers/net/ethernet/freescale/gianfar.c > index f34ca55..9ea887e 100644 > --- a/drivers/net/ethernet/freescale/gianfar.c > +++ b/drivers/net/ethernet/freescale/gianfar.c > @@ -2296,6 +2296,12 @@ static int gfar_start_xmit(struct sk_buff *skb, > struct net_device *dev) > 0, > frag_len, > DMA_TO_DEVICE); > + if (unlikely(dma_mapping_error(priv->dev, bufaddr))) { > + /* As DMA mapping failed, pretend the TX path > + * is busy to retry later > + */ > + return NETDEV_TX_BUSY; > + } > > /* set the TxBD length and buffer pointer */ > txbdp->bufPtr = bufaddr; > @@ -2345,8 +2351,15 @@ static int gfar_start_xmit(struct sk_buff *skb, > struct net_device *dev) > fcb->ptp = 1; > } > > - txbdp_start->bufPtr = dma_map_single(priv->dev, skb->data, > - skb_headlen(skb), DMA_TO_DEVICE); > + bufaddr = dma_map_single(priv->dev, skb->data, skb_headlen(skb), > + DMA_TO_DEVICE); > + if (unlikely(dma_mapping_error(priv->dev, bufaddr))) { > + /* As DMA mapping failed, pretend the TX path is busy to retry > + * later > + */ > + return NETDEV_TX_BUSY; > + } > + txbdp_start->bufPtr = bufaddr; > > /* If time stamping is requested one additional TxBD must be set up. The > * first TxBD points to the FCB and must have a data length of > -- You have to return TX_BUSY in the case of the full hw queue. Have you tested your changes with fault injection? > 2.2.0 > > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/