From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Kirsher Subject: [net-next PATCH 08/11] ixgbe: Add a few safety nets for register writes and descriptor cleanups Date: Sat, 14 Mar 2009 01:14:50 -0700 Message-ID: <20090314081450.4687.87025.stgit@lost.foo-projects.org> References: <20090314081229.4687.40245.stgit@lost.foo-projects.org> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, gospo@redhat.com, Jesse Brandeburg , Peter P Waskiewicz Jr , Jeff Kirsher To: davem@davemloft.net Return-path: Received: from qmta11.westchester.pa.mail.comcast.net ([76.96.59.211]:37979 "EHLO QMTA11.westchester.pa.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752791AbZCNIU6 (ORCPT ); Sat, 14 Mar 2009 04:20:58 -0400 In-Reply-To: <20090314081229.4687.40245.stgit@lost.foo-projects.org> Sender: netdev-owner@vger.kernel.org List-ID: From: Jesse Brandeburg There are possible times that a driver may fail to completely initialize, due to a buggy platform or a buggy kernel. In those cases, we'd rather fail gracefully instead of a panic. Add a few safety checks to some critical paths to try and prevent a panic in these corner-case situations. Signed-off-by: Jesse Brandeburg Signed-off-by: Peter P Waskiewicz Jr Signed-off-by: Jeff Kirsher --- drivers/net/ixgbe/ixgbe_main.c | 18 ++++++++++++------ 1 files changed, 12 insertions(+), 6 deletions(-) diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c index 78b0357..8821c5f 100644 --- a/drivers/net/ixgbe/ixgbe_main.c +++ b/drivers/net/ixgbe/ixgbe_main.c @@ -2458,8 +2458,10 @@ static void ixgbe_clean_rx_ring(struct ixgbe_adapter *adapter, rx_ring->next_to_clean = 0; rx_ring->next_to_use = 0; - writel(0, adapter->hw.hw_addr + rx_ring->head); - writel(0, adapter->hw.hw_addr + rx_ring->tail); + if (rx_ring->head) + writel(0, adapter->hw.hw_addr + rx_ring->head); + if (rx_ring->tail) + writel(0, adapter->hw.hw_addr + rx_ring->tail); } /** @@ -2490,8 +2492,10 @@ static void ixgbe_clean_tx_ring(struct ixgbe_adapter *adapter, tx_ring->next_to_use = 0; tx_ring->next_to_clean = 0; - writel(0, adapter->hw.hw_addr + tx_ring->head); - writel(0, adapter->hw.hw_addr + tx_ring->tail); + if (tx_ring->head) + writel(0, adapter->hw.hw_addr + tx_ring->head); + if (tx_ring->tail) + writel(0, adapter->hw.hw_addr + tx_ring->tail); } /** @@ -3327,7 +3331,8 @@ static void ixgbe_free_all_tx_resources(struct ixgbe_adapter *adapter) int i; for (i = 0; i < adapter->num_tx_queues; i++) - ixgbe_free_tx_resources(adapter, &adapter->tx_ring[i]); + if (adapter->tx_ring[i].desc) + ixgbe_free_tx_resources(adapter, &adapter->tx_ring[i]); } /** @@ -3363,7 +3368,8 @@ static void ixgbe_free_all_rx_resources(struct ixgbe_adapter *adapter) int i; for (i = 0; i < adapter->num_rx_queues; i++) - ixgbe_free_rx_resources(adapter, &adapter->rx_ring[i]); + if (adapter->rx_ring[i].desc) + ixgbe_free_rx_resources(adapter, &adapter->rx_ring[i]); } /**