From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756008Ab1G1Xo2 (ORCPT ); Thu, 28 Jul 2011 19:44:28 -0400 Received: from mga02.intel.com ([134.134.136.20]:30203 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755994Ab1G1XoK (ORCPT ); Thu, 28 Jul 2011 19:44:10 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.67,285,1309762800"; d="scan'208";a="33351749" From: Andi Kleen References: <20110728444.299940435@firstfloor.org> In-Reply-To: <20110728444.299940435@firstfloor.org> To: cooldavid@cooldavid.org, chrisw@sous-sol.org, davem@davemloft.net, ak@linux.intel.com, linux-kernel@vger.kernel.org, stable@kernel.org, tim.bird@am.sony.com Subject: [PATCH] [6/50] jme: Fix unmap error (Causing system freeze) Message-Id: <20110728234410.686042403FF@tassilo.jf.intel.com> Date: Thu, 28 Jul 2011 16:44:10 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.35-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Guo-Fu Tseng [ upstream commit 94c5b41b327e08de0ddf563237855f55080652a1 ] This patch add the missing dma_unmap(). Which solved the critical issue of system freeze on heavy load. Michal Miroslaw's rejected patch: [PATCH v2 10/46] net: jme: convert to generic DMA API Pointed out the issue also, thank you Michal. But the fix was incorrect. It would unmap needed address when low memory. Got lots of feedback from End user and Gentoo Bugzilla. https://bugs.gentoo.org/show_bug.cgi?id=373109 Thank you all. :) Cc: stable@kernel.org Signed-off-by: Guo-Fu Tseng Acked-by: Chris Wright Signed-off-by: David S. Miller Signed-off-by: Andi Kleen Index: linux-2.6.35.y/drivers/net/jme.c =================================================================== --- linux-2.6.35.y.orig/drivers/net/jme.c +++ linux-2.6.35.y/drivers/net/jme.c @@ -678,20 +678,28 @@ jme_make_new_rx_buf(struct jme_adapter * struct jme_ring *rxring = &(jme->rxring[0]); struct jme_buffer_info *rxbi = rxring->bufinf + i; struct sk_buff *skb; + dma_addr_t mapping; skb = netdev_alloc_skb(jme->dev, jme->dev->mtu + RX_EXTRA_LEN); if (unlikely(!skb)) return -ENOMEM; + mapping = pci_map_page(jme->pdev, virt_to_page(skb->data), + offset_in_page(skb->data), skb_tailroom(skb), + PCI_DMA_FROMDEVICE); + if (unlikely(pci_dma_mapping_error(jme->pdev, mapping))) { + dev_kfree_skb(skb); + return -ENOMEM; + } + + if (likely(rxbi->mapping)) + pci_unmap_page(jme->pdev, rxbi->mapping, + rxbi->len, PCI_DMA_FROMDEVICE); + rxbi->skb = skb; rxbi->len = skb_tailroom(skb); - rxbi->mapping = pci_map_page(jme->pdev, - virt_to_page(skb->data), - offset_in_page(skb->data), - rxbi->len, - PCI_DMA_FROMDEVICE); - + rxbi->mapping = mapping; return 0; }