From mboxrd@z Thu Jan 1 00:00:00 1970 From: Troy Kisky Subject: Re: [PATCH net-next V3 00/16] net: fec: cleanup and fixes Date: Thu, 14 Apr 2016 08:39:04 -0700 Message-ID: <570FB998.2080900@boundarydevices.com> References: <1459909562-22865-1-git-send-email-troy.kisky@boundarydevices.com> <87h9f4ebvp.fsf@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, davem@davemloft.net, fugang.duan@nxp.com, lznuaa@gmail.com, andrew@lunn.ch, stillcompiling@gmail.com, arnd@arndb.de, sergei.shtylyov@cogentembedded.com, gerg@uclinux.org, fabio.estevam@nxp.com, johannes@sipsolutions.net, l.stach@pengutronix.de, linux-arm-kernel@lists.infradead.org, tremyfr@gmail.com To: Holger Schurig Return-path: Received: from mail-pf0-f179.google.com ([209.85.192.179]:35887 "EHLO mail-pf0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755379AbcDNPjG (ORCPT ); Thu, 14 Apr 2016 11:39:06 -0400 Received: by mail-pf0-f179.google.com with SMTP id e128so46997061pfe.3 for ; Thu, 14 Apr 2016 08:39:05 -0700 (PDT) In-Reply-To: <87h9f4ebvp.fsf@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On 4/14/2016 3:13 AM, Holger Schurig wrote: > Do you guys that work with the FEC driver ever run with > CONFIG_DMA_API_DEBUG enabled? > > I ask this Because I get this error when it's turned on when I do some > "rsync" transfer to my device: > > [ 58.420980] ------------[ cut here ]------------ > [ 58.425667] WARNING: CPU: 0 PID: 377 at /home/schurig/d/mkarm/linux-4.5/lib/dma-debug.c:1096 check_unmap+0x9d0/0xab8() > [ 58.436405] fec 2188000.ethernet: DMA-API: device driver tries to free DMA memory it has not allocated [device address=0x0000000000000000] [size=66 bytes] > [ 58.450248] Modules linked in: bnep usbhid imx_sdma flexcan btusb btrtl btbcm btintel smsc95xx usbnet mii bluetooth > [ 58.460882] CPU: 0 PID: 377 Comm: sshd Tainted: G W 4.5.1 #3 > [ 58.467671] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) > [ 58.474199] Backtrace: > [ 58.476675] [] (dump_backtrace) from [] (show_stack+0x18/0x1c) > [ 58.484244] r6:60000113 r5:c05a96c0 r4:00000000 r3:00000000 > [ 58.489964] [] (show_stack) from [] (dump_stack+0x9c/0xb0) > [ 58.497197] [] (dump_stack) from [] (warn_slowpath_common+0x8c/0xbc) > [ 58.505286] r6:c01f9c74 r5:00000009 r4:ee9f17f8 r3:c0596da4 > [ 58.511002] [] (warn_slowpath_common) from [] (warn_slowpath_fmt+0x38/0x40) > [ 58.519698] r8:00000042 r7:00000001 r6:00000000 r5:00000000 r4:c050c020 > [ 58.526470] [] (warn_slowpath_fmt) from [] (check_unmap+0x9d0/0xab8) > [ 58.534559] r3:c0520e6c r2:c050c020 > [ 58.538159] r4:00000000 > [ 58.540710] [] (check_unmap) from [] (debug_dma_unmap_page+0x84/0x8c) > [ 58.548886] r10:ef2ec000 r9:f09e5fa0 r8:ef0ef810 r7:00000001 r6:00000000 r5:00000042 > [ 58.556780] r4:00000001 > [ 58.559336] [] (debug_dma_unmap_page) from [] (fec_txq+0x140/0x31c) > [ 58.567338] r8:ef0ef810 r7:00000000 r6:00000000 r5:00000000 r4:ef2c6000 > [ 58.574108] [] (fec_txq) from [] (fec_enet_napi_q1+0x98/0xe8) > [ 58.581589] r10:08000000 r9:ef2ec580 r8:00000000 r7:00000040 r6:00000000 r5:ef2ec000 I think I've already fixed this, but I've only submitted once. commit 466cb4a2e5583d2e18470f30d5948edcf4b947f5 Author: Troy Kisky Date: Wed Jan 20 12:52:10 2016 -0700 net: fec: update dirty_tx even if no skb If dirty_tx isn't updated, then dma_unmap_single will be called twice. Signed-off-by: Troy Kisky diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index 452be9c..150a90a 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -1243,10 +1243,8 @@ static void fec_txq(struct net_device *ndev, struct fec_enet_priv_tx_q *txq) fec16_to_cpu(bdp->cbd_datlen), DMA_TO_DEVICE); bdp->cbd_bufaddr = cpu_to_fec32(0); - if (!skb) { - bdp = fec_enet_get_nextdesc(bdp, &txq->bd); - continue; - } + if (!skb) + goto skb_done; /* Check for errors. */ if (status & (BD_ENET_TX_HB | BD_ENET_TX_LC | @@ -1285,7 +1283,7 @@ static void fec_txq(struct net_device *ndev, struct fec_enet_priv_tx_q *txq) /* Free the sk buffer associated with this last transmit */ dev_kfree_skb_any(skb); - +skb_done: /* Make sure the update to bdp and tx_skbuff are performed * before dirty_tx */