[TG3]: Fix bug in tg3_rx()

This patch fixes a bug that causes tg3_has_work() to always return 1.

rx work is determined by comparing tp->rx_rcb_ptr with the current hw
producer index. The hw producer index is modulo the ring size, but tp-
>rx_rcb_ptr is a free running counter that goes up beyond the ring size.
After the ring wraps around once, tg3_has_work() will always return 1.

The fix is to always do modulo arithmetic on tp->rx_rcb_ptr.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Michael Chan 2005-04-25 15:14:03 -07:00 committed by David S. Miller
parent cbdbf00aaf
commit 483ba50bd4

View file

@ -2686,8 +2686,8 @@ static int tg3_vlan_rx(struct tg3 *tp, struct sk_buff *skb, u16 vlan_tag)
static int tg3_rx(struct tg3 *tp, int budget)
{
u32 work_mask;
u32 rx_rcb_ptr = tp->rx_rcb_ptr;
u16 hw_idx, sw_idx;
u32 sw_idx = tp->rx_rcb_ptr;
u16 hw_idx;
int received;
hw_idx = tp->hw_status->idx[0].rx_producer;
@ -2696,7 +2696,6 @@ static int tg3_rx(struct tg3 *tp, int budget)
* the opaque cookie.
*/
rmb();
sw_idx = rx_rcb_ptr % TG3_RX_RCB_RING_SIZE(tp);
work_mask = 0;
received = 0;
while (sw_idx != hw_idx && budget > 0) {
@ -2801,14 +2800,13 @@ static int tg3_rx(struct tg3 *tp, int budget)
next_pkt:
(*post_ptr)++;
next_pkt_nopost:
rx_rcb_ptr++;
sw_idx = rx_rcb_ptr % TG3_RX_RCB_RING_SIZE(tp);
sw_idx++;
sw_idx %= TG3_RX_RCB_RING_SIZE(tp);
}
/* ACK the status ring. */
tp->rx_rcb_ptr = rx_rcb_ptr;
tw32_rx_mbox(MAILBOX_RCVRET_CON_IDX_0 + TG3_64BIT_REG_LOW,
(rx_rcb_ptr % TG3_RX_RCB_RING_SIZE(tp)));
tp->rx_rcb_ptr = sw_idx;
tw32_rx_mbox(MAILBOX_RCVRET_CON_IDX_0 + TG3_64BIT_REG_LOW, sw_idx);
/* Refill RX ring(s). */
if (work_mask & RXD_OPAQUE_RING_STD) {