From patchwork Tue Sep 21 07:15:19 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislaw Gruszka X-Patchwork-Id: 65276 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 4610DB70AA for ; Tue, 21 Sep 2010 17:14:23 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755953Ab0IUHOS (ORCPT ); Tue, 21 Sep 2010 03:14:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49456 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755739Ab0IUHOR (ORCPT ); Tue, 21 Sep 2010 03:14:17 -0400 Received: from int-mx03.intmail.prod.int.phx2.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.16]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o8L7E983013108 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 21 Sep 2010 03:14:09 -0400 Received: from localhost (dhcp-26-173.brq.redhat.com [10.34.26.173]) by int-mx03.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o8L7E8fs002654; Tue, 21 Sep 2010 03:14:08 -0400 Date: Tue, 21 Sep 2010 09:15:19 +0200 From: Stanislaw Gruszka To: Stephen Hemminger , netdev@vger.kernel.org Subject: [RFC] skge: limit DMA to 32 bit Message-ID: <20100921071518.GA9081@redhat.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-12-10) X-Scanned-By: MIMEDefang 2.67 on 10.5.11.16 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org We have old fedora bug report about not working skge device on some Gigabyte motherboard: https://bugzilla.redhat.com/show_bug.cgi?id=447489 In dmesg there are messages: skge 0000:02:0b.0: PCI error cmd=0x7 status=0x22b0 skge 0000:02:0b.0: unable to clear error (so ignoring them) Status value 0x22b0 include PCI_STATUS_REC_MASTER_ABORT bit set, what mean that DMA transfer on PCI bus was aborted. I provided to user modified driver with module parameter, that allow to experiment with different dma_mask's. He told that maximum working dma_mask for him is 32 bits set. Is 32bit DMA limit for every skge device acceptable patch? Note, patch change possible driver DMA address space as below: - 32bit - no change, still low mem only (896MB) - 32bit-PAE - down from 36bit to low mem (896MB) - 64bit - down from 64bit to 32bit --- 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 diff --git a/drivers/net/skge.c b/drivers/net/skge.c index a8a6358..1a674e3 100644 --- a/drivers/net/skge.c +++ b/drivers/net/skge.c @@ -3797,8 +3797,7 @@ static const struct net_device_ops skge_netdev_ops = { /* Initialize network device */ -static struct net_device *skge_devinit(struct skge_hw *hw, int port, - int highmem) +static struct net_device *skge_devinit(struct skge_hw *hw, int port) { struct skge_port *skge; struct net_device *dev = alloc_etherdev(sizeof(*skge)); @@ -3814,9 +3813,6 @@ static struct net_device *skge_devinit(struct skge_hw *hw, int port, dev->watchdog_timeo = TX_WATCHDOG; dev->irq = hw->pdev->irq; - if (highmem) - dev->features |= NETIF_F_HIGHDMA; - skge = netdev_priv(dev); netif_napi_add(dev, &skge->napi, skge_poll, NAPI_WEIGHT); skge->netdev = dev; @@ -3874,7 +3870,7 @@ static int __devinit skge_probe(struct pci_dev *pdev, { struct net_device *dev, *dev1; struct skge_hw *hw; - int err, using_dac = 0; + int err; err = pci_enable_device(pdev); if (err) { @@ -3890,13 +3886,9 @@ static int __devinit skge_probe(struct pci_dev *pdev, pci_set_master(pdev); - if (!pci_set_dma_mask(pdev, DMA_BIT_MASK(64))) { - using_dac = 1; - err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64)); - } else if (!(err = pci_set_dma_mask(pdev, DMA_BIT_MASK(32)))) { - using_dac = 0; + err = pci_set_dma_mask(pdev, DMA_BIT_MASK(32)); + if (!err) err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32)); - } if (err) { dev_err(&pdev->dev, "no usable DMA configuration\n"); @@ -3944,7 +3936,7 @@ static int __devinit skge_probe(struct pci_dev *pdev, (unsigned long long)pci_resource_start(pdev, 0), pdev->irq, skge_board_name(hw), hw->chip_rev); - dev = skge_devinit(hw, 0, using_dac); + dev = skge_devinit(hw, 0); if (!dev) goto err_out_led_off; @@ -3967,7 +3959,7 @@ static int __devinit skge_probe(struct pci_dev *pdev, skge_show_addr(dev); if (hw->ports > 1) { - dev1 = skge_devinit(hw, 1, using_dac); + dev1 = skge_devinit(hw, 1); if (dev1 && register_netdev(dev1) == 0) skge_show_addr(dev1); else {