From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Poirier Subject: [PATCH net v3 2/4] tg3: Fix tx_pending check for MAX_SKB_FRAGS Date: Tue, 26 Aug 2014 12:26:16 -0700 Message-ID: <1409081178-4877-2-git-send-email-bpoirier@suse.de> References: <1409081178-4877-1-git-send-email-bpoirier@suse.de> Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Prashant Sreedharan , Michael Chan Return-path: In-Reply-To: <1409081178-4877-1-git-send-email-bpoirier@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org The rest of the driver assumes at least one free descriptor in the tx ring. Therefore, since an skb with max frags takes up (MAX_SKB_FRAGS + 1) descriptors, tx_pending must be > (MAX_SKB_FRAGS + 1). Signed-off-by: Benjamin Poirier --- Changes v1->v2 Moved ahead in the series from 3/3 to 2/3, no functionnal change I reproduced this bug using the same approach explained in patch 1. The bug reproduces with tx_pending = 18 --- drivers/net/ethernet/broadcom/tg3.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c index b11c0fd..0cecd6d 100644 --- a/drivers/net/ethernet/broadcom/tg3.c +++ b/drivers/net/ethernet/broadcom/tg3.c @@ -12319,7 +12319,7 @@ static int tg3_set_ringparam(struct net_device *dev, struct ethtool_ringparam *e if ((ering->rx_pending > tp->rx_std_ring_mask) || (ering->rx_jumbo_pending > tp->rx_jmb_ring_mask) || (ering->tx_pending > TG3_TX_RING_SIZE - 1) || - (ering->tx_pending <= MAX_SKB_FRAGS) || + (ering->tx_pending <= MAX_SKB_FRAGS + 1) || (tg3_flag(tp, TSO_BUG) && (ering->tx_pending <= (MAX_SKB_FRAGS * 3)))) return -EINVAL; -- 1.8.4.5