From patchwork Mon Apr 13 17:27:42 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Felix Fietkau X-Patchwork-Id: 460858 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 BD6B614011D for ; Tue, 14 Apr 2015 03:27:57 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932492AbbDMR1x (ORCPT ); Mon, 13 Apr 2015 13:27:53 -0400 Received: from static.88-198-24-112.clients.your-server.de ([88.198.24.112]:51989 "EHLO nbd.name" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753427AbbDMR1v (ORCPT ); Mon, 13 Apr 2015 13:27:51 -0400 Received: by nf.local (Postfix, from userid 501) id 1A590DAEB8CF; Mon, 13 Apr 2015 19:27:48 +0200 (CEST) From: Felix Fietkau To: netdev@vger.kernel.org Cc: zajec5@gmail.com, hauke@hauke-m.de Subject: [PATCH v5 4/9] bgmac: simplify rx DMA error handling Date: Mon, 13 Apr 2015 19:27:42 +0200 Message-Id: <1428946067-75650-4-git-send-email-nbd@openwrt.org> X-Mailer: git-send-email 2.2.2 In-Reply-To: <1428946067-75650-1-git-send-email-nbd@openwrt.org> References: <1428946067-75650-1-git-send-email-nbd@openwrt.org> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Unmap the DMA buffer before checking it. If an error occurs, free the buffer and allocate a new one. If allocation or mapping fails, retry as long as there is NAPI poll budget left (count every attempt instead of every frame). Signed-off-by: Felix Fietkau --- drivers/net/ethernet/broadcom/bgmac.c | 56 +++++++++++++---------------------- 1 file changed, 20 insertions(+), 36 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bgmac.c b/drivers/net/ethernet/broadcom/bgmac.c index 9a6742e..1916ebc 100644 --- a/drivers/net/ethernet/broadcom/bgmac.c +++ b/drivers/net/ethernet/broadcom/bgmac.c @@ -404,51 +404,33 @@ static int bgmac_dma_rx_read(struct bgmac *bgmac, struct bgmac_dma_ring *ring, void *buf = slot->buf; u16 len, flags; - /* Unmap buffer to make it accessible to the CPU */ - dma_sync_single_for_cpu(dma_dev, slot->dma_addr, - BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE); - - /* Get info from the header */ - len = le16_to_cpu(rx->len); - flags = le16_to_cpu(rx->flags); + if (++handled >= weight - 1) /* Should never be greater */ + break; do { - dma_addr_t old_dma_addr = slot->dma_addr; - int err; + if (!slot->dma_addr) + break; + + /* Unmap buffer to make it accessible to the CPU */ + dma_unmap_single(dma_dev, slot->dma_addr, + BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE); + slot->dma_addr = 0; + + /* Get info from the header */ + len = le16_to_cpu(rx->len); + flags = le16_to_cpu(rx->flags); /* Check for poison and drop or pass the packet */ if (len == 0xdead && flags == 0xbeef) { bgmac_err(bgmac, "Found poisoned packet at slot %d, DMA issue!\n", ring->start); - dma_sync_single_for_device(dma_dev, - slot->dma_addr, - BGMAC_RX_BUF_SIZE, - DMA_FROM_DEVICE); + kfree(buf); break; } /* Omit CRC. */ len -= ETH_FCS_LEN; - /* Prepare new skb as replacement */ - err = bgmac_dma_rx_skb_for_slot(bgmac, slot); - if (err) { - /* Poison the old skb */ - rx->len = cpu_to_le16(0xdead); - rx->flags = cpu_to_le16(0xbeef); - - dma_sync_single_for_device(dma_dev, - slot->dma_addr, - BGMAC_RX_BUF_SIZE, - DMA_FROM_DEVICE); - break; - } - bgmac_dma_rx_setup_desc(bgmac, ring, ring->start); - - /* Unmap old skb, we'll pass it to the netfif */ - dma_unmap_single(dma_dev, old_dma_addr, - BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE); - skb = build_skb(buf, BGMAC_RX_ALLOC_SIZE); skb_put(skb, BGMAC_RX_FRAME_OFFSET + BGMAC_RX_BUF_OFFSET + len); @@ -458,14 +440,16 @@ static int bgmac_dma_rx_read(struct bgmac *bgmac, struct bgmac_dma_ring *ring, skb_checksum_none_assert(skb); skb->protocol = eth_type_trans(skb, bgmac->net_dev); napi_gro_receive(&bgmac->napi, skb); - handled++; } while (0); + /* Prepare new skb as replacement */ + if (bgmac_dma_rx_skb_for_slot(bgmac, slot)) + continue; + + bgmac_dma_rx_setup_desc(bgmac, ring, ring->start); + if (++ring->start >= BGMAC_RX_RING_SLOTS) ring->start = 0; - - if (handled >= weight) /* Should never be greater */ - break; } return handled;