From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Fainelli Subject: [PATCH net v2 1/3] net: bcmgenet: fix off-by-one in incrementing read pointer Date: Fri, 10 Oct 2014 10:51:52 -0700 Message-ID: <1412963514-7718-2-git-send-email-f.fainelli@gmail.com> References: <1412963514-7718-1-git-send-email-f.fainelli@gmail.com> Cc: davem@davemloft.net, pgynther@google.com, jaedon.shin@gmail.com, Florian Fainelli To: netdev@vger.kernel.org Return-path: Received: from mail-pa0-f43.google.com ([209.85.220.43]:40510 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751802AbaJJRwI (ORCPT ); Fri, 10 Oct 2014 13:52:08 -0400 Received: by mail-pa0-f43.google.com with SMTP id lf10so2169365pab.2 for ; Fri, 10 Oct 2014 10:52:08 -0700 (PDT) In-Reply-To: <1412963514-7718-1-git-send-email-f.fainelli@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: Commit b629be5c8399d7c423b92135eb43a86c924d1cbc ("net: bcmgenet: check harder for out of memory conditions") moved the increment of the local read pointer *before* reading from the hardware descriptor using dmadesc_get_length_status(), which creates an off-by-one situation. Fix this by moving again the read_ptr increment after we have read the hardware descriptor to get both the control block and the read pointer back in sync. Fixes: b629be5c8399 ("net: bcmgenet: check harder for out of memory conditions") Signed-off-by: Jaedon Shin Signed-off-by: Florian Fainelli --- Changes in v2: - moved the rxpktprocessed and rx_read_ptr increment after refiling the control block drivers/net/ethernet/broadcom/genet/bcmgenet.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c index fff2634b6f34..fdc9ec09e453 100644 --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c @@ -1285,11 +1285,6 @@ static unsigned int bcmgenet_desc_rx(struct bcmgenet_priv *priv, cb = &priv->rx_cbs[priv->rx_read_ptr]; skb = cb->skb; - rxpktprocessed++; - - priv->rx_read_ptr++; - priv->rx_read_ptr &= (priv->num_rx_bds - 1); - /* We do not have a backing SKB, so we do not have a * corresponding DMA mapping for this incoming packet since * bcmgenet_rx_refill always either has both skb and mapping or @@ -1404,6 +1399,10 @@ refill: err = bcmgenet_rx_refill(priv, cb); if (err) netif_err(priv, rx_err, dev, "Rx refill failed\n"); + + rxpktprocessed++; + priv->rx_read_ptr++; + priv->rx_read_ptr &= (priv->num_rx_bds - 1); } return rxpktprocessed; -- 1.9.1