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Commit ab5adecb authored by Stephen Hemminger's avatar Stephen Hemminger Committed by Jeff Garzik
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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: default avatarStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent ac93a394

drivers/net/sky2.c

+9 −3
Original line number Diff line number Diff line
@@ -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);