Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751647AbaLEKic (ORCPT ); Fri, 5 Dec 2014 05:38:32 -0500 Received: from ispman.iskranet.ru ([62.213.33.10]:50730 "EHLO ispman.iskranet.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750840AbaLEKi2 (ORCPT ); Fri, 5 Dec 2014 05:38:28 -0500 From: Arseny Solokha To: Claudiu Manoil Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Arseny Solokha Subject: [PATCH 2/2] gianfar: handle map error in gfar_start_xmit() Date: Fri, 5 Dec 2014 17:37:54 +0700 Message-Id: <1417775874-17775-3-git-send-email-asolokha@kb.kras.ru> X-Mailer: git-send-email 2.2.0 In-Reply-To: <1417775874-17775-1-git-send-email-asolokha@kb.kras.ru> References: <1417775874-17775-1-git-send-email-asolokha@kb.kras.ru> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 -- 2.2.0 -- 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/