From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:49137 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755953AbcGGAoq (ORCPT ); Wed, 6 Jul 2016 20:44:46 -0400 Subject: Patch "net: alx: Work around the DMA RX overflow issue" has been added to the 3.14-stable tree To: feng.tang@intel.com, edumazet@google.com, gregkh@linuxfoundation.org, olelukoie@mail.ru Cc: , From: Date: Wed, 06 Jul 2016 17:44:55 -0700 Message-ID: <1467852295222163@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled net: alx: Work around the DMA RX overflow issue to the 3.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-alx-work-around-the-dma-rx-overflow-issue.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Wed Jul 6 17:30:58 PDT 2016 From: Feng Tang Date: Fri, 24 Jun 2016 15:26:05 +0800 Subject: net: alx: Work around the DMA RX overflow issue Status: RO Content-Length: 1764 Lines: 47 From: Feng Tang [ Upstream commit 881d0327db37ad917a367c77aff1afa1ee41e0a9 ] Note: This is a verified backported patch for stable 4.4 kernel, and it could also be applied to 4.3/4.2/4.1/3.18/3.16 There is a problem with alx devices, that the network link will be lost in 1-5 minutes after the device is up. >>>From debugging without datasheet, we found the error always happen when the DMA RX address is set to 0x....fc0, which is very likely to be a HW/silicon problem. This patch will apply rx skb with 64 bytes longer space, and if the allocated skb has a 0x...fc0 address, it will use skb_resever(skb, 64) to advance the address, so that the RX overflow can be avoided. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=70761 Signed-off-by: Feng Tang Suggested-by: Eric Dumazet Tested-by: Ole Lukoie Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/atheros/alx/main.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/drivers/net/ethernet/atheros/alx/main.c +++ b/drivers/net/ethernet/atheros/alx/main.c @@ -86,9 +86,14 @@ static int alx_refill_rx_ring(struct alx while (!cur_buf->skb && next != rxq->read_idx) { struct alx_rfd *rfd = &rxq->rfd[cur]; - skb = __netdev_alloc_skb(alx->dev, alx->rxbuf_size, gfp); + skb = __netdev_alloc_skb(alx->dev, alx->rxbuf_size + 64, gfp); if (!skb) break; + + /* Workround for the HW RX DMA overflow issue */ + if (((unsigned long)skb->data & 0xfff) == 0xfc0) + skb_reserve(skb, 64); + dma = dma_map_single(&alx->hw.pdev->dev, skb->data, alx->rxbuf_size, DMA_FROM_DEVICE); Patches currently in stable-queue which might be from feng.tang@intel.com are queue-3.14/net-alx-work-around-the-dma-rx-overflow-issue.patch