From ab5adecb2d02f3688719dfb5936a82833fcc3955 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Mon, 5 Nov 2007 15:52:09 -0800 Subject: [PATCH] sky2: status ring race fix The D-Link PCI-X board (and maybe others) can lie about status ring entries. It seems it will update the register for last status index before completing the DMA for the ring entry. To avoid reading stale data, zap the old entry and check. Signed-off-by: Stephen Hemminger Signed-off-by: Jeff Garzik --- drivers/net/sky2.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c index 4f41a9445961..706884ae8fcd 100644 --- a/drivers/net/sky2.c +++ b/drivers/net/sky2.c @@ -2247,20 +2247,26 @@ static int sky2_status_intr(struct sky2_hw *hw, int to_do, u16 idx) do { struct sky2_port *sky2; struct sky2_status_le *le = hw->st_le + hw->st_idx; - unsigned port = le->css & CSS_LINK_BIT; + unsigned port; struct net_device *dev; struct sk_buff *skb; u32 status; u16 length; + u8 opcode = le->opcode; + + if (!(opcode & HW_OWNER)) + break; hw->st_idx = RING_NEXT(hw->st_idx, STATUS_RING_SIZE); + port = le->css & CSS_LINK_BIT; dev = hw->dev[port]; sky2 = netdev_priv(dev); length = le16_to_cpu(le->length); status = le32_to_cpu(le->status); - switch (le->opcode & ~HW_OWNER) { + le->opcode = 0; + switch (opcode & ~HW_OWNER) { case OP_RXSTAT: ++rx[port]; skb = sky2_receive(dev, length, status); @@ -2353,7 +2359,7 @@ static int sky2_status_intr(struct sky2_hw *hw, int to_do, u16 idx) default: if (net_ratelimit()) printk(KERN_WARNING PFX - "unknown status opcode 0x%x\n", le->opcode); + "unknown status opcode 0x%x\n", opcode); } } while (hw->st_idx != idx);