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authorMichael Chan <mchan@broadcom.com>2007-12-10 20:18:37 -0500
committerDavid S. Miller <davem@sunset.davemloft.net>2007-12-11 05:45:30 -0500
commitc09c262783dcac62352293912d82b794063cefc3 (patch)
tree14941c7d5c49bbfa3e2b2a3d61cba274baea6b05 /drivers/net/bnx2.c
parentfb0c18bd1f61086fcfac90017b59891a356cc288 (diff)
[BNX2]: Fix RX packet rot.
Packets can be left in the RX ring if the NAPI budget is reached. This is caused by storing the latest rx index at the beginning of bnx2_rx_int(). We may not process all the work up to this index if the budget is reached and so some packets in the RX ring may rot when we later check for more work using this stored rx index. The fix is to not store this latest hw index and only store the processed rx index. We use a new function bnx2_get_hw_rx_cons() to fetch the latest hw rx index. Signed-off-by: Michael Chan <mchan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/bnx2.c')
-rw-r--r--drivers/net/bnx2.c26
1 files changed, 14 insertions, 12 deletions
diff --git a/drivers/net/bnx2.c b/drivers/net/bnx2.c
index a4f3832d0a6..f9eea6e84c8 100644
--- a/drivers/net/bnx2.c
+++ b/drivers/net/bnx2.c
@@ -2387,18 +2387,24 @@ bnx2_reuse_rx_skb(struct bnx2 *bp, struct sk_buff *skb,
2387 prod_bd->rx_bd_haddr_lo = cons_bd->rx_bd_haddr_lo; 2387 prod_bd->rx_bd_haddr_lo = cons_bd->rx_bd_haddr_lo;
2388} 2388}
2389 2389
2390static inline u16
2391bnx2_get_hw_rx_cons(struct bnx2 *bp)
2392{
2393 u16 cons = bp->status_blk->status_rx_quick_consumer_index0;
2394
2395 if (unlikely((cons & MAX_RX_DESC_CNT) == MAX_RX_DESC_CNT))
2396 cons++;
2397 return cons;
2398}
2399
2390static int 2400static int
2391bnx2_rx_int(struct bnx2 *bp, int budget) 2401bnx2_rx_int(struct bnx2 *bp, int budget)
2392{ 2402{
2393 struct status_block *sblk = bp->status_blk;
2394 u16 hw_cons, sw_cons, sw_ring_cons, sw_prod, sw_ring_prod; 2403 u16 hw_cons, sw_cons, sw_ring_cons, sw_prod, sw_ring_prod;
2395 struct l2_fhdr *rx_hdr; 2404 struct l2_fhdr *rx_hdr;
2396 int rx_pkt = 0; 2405 int rx_pkt = 0;
2397 2406
2398 hw_cons = bp->hw_rx_cons = sblk->status_rx_quick_consumer_index0; 2407 hw_cons = bnx2_get_hw_rx_cons(bp);
2399 if ((hw_cons & MAX_RX_DESC_CNT) == MAX_RX_DESC_CNT) {
2400 hw_cons++;
2401 }
2402 sw_cons = bp->rx_cons; 2408 sw_cons = bp->rx_cons;
2403 sw_prod = bp->rx_prod; 2409 sw_prod = bp->rx_prod;
2404 2410
@@ -2515,10 +2521,7 @@ next_rx:
2515 2521
2516 /* Refresh hw_cons to see if there is new work */ 2522 /* Refresh hw_cons to see if there is new work */
2517 if (sw_cons == hw_cons) { 2523 if (sw_cons == hw_cons) {
2518 hw_cons = bp->hw_rx_cons = 2524 hw_cons = bnx2_get_hw_rx_cons(bp);
2519 sblk->status_rx_quick_consumer_index0;
2520 if ((hw_cons & MAX_RX_DESC_CNT) == MAX_RX_DESC_CNT)
2521 hw_cons++;
2522 rmb(); 2525 rmb();
2523 } 2526 }
2524 } 2527 }
@@ -2622,7 +2625,7 @@ bnx2_has_work(struct bnx2 *bp)
2622{ 2625{
2623 struct status_block *sblk = bp->status_blk; 2626 struct status_block *sblk = bp->status_blk;
2624 2627
2625 if ((sblk->status_rx_quick_consumer_index0 != bp->hw_rx_cons) || 2628 if ((bnx2_get_hw_rx_cons(bp) != bp->rx_cons) ||
2626 (sblk->status_tx_quick_consumer_index0 != bp->hw_tx_cons)) 2629 (sblk->status_tx_quick_consumer_index0 != bp->hw_tx_cons))
2627 return 1; 2630 return 1;
2628 2631
@@ -2655,7 +2658,7 @@ static int bnx2_poll_work(struct bnx2 *bp, int work_done, int budget)
2655 if (sblk->status_tx_quick_consumer_index0 != bp->hw_tx_cons) 2658 if (sblk->status_tx_quick_consumer_index0 != bp->hw_tx_cons)
2656 bnx2_tx_int(bp); 2659 bnx2_tx_int(bp);
2657 2660
2658 if (sblk->status_rx_quick_consumer_index0 != bp->hw_rx_cons) 2661 if (bnx2_get_hw_rx_cons(bp) != bp->rx_cons)
2659 work_done += bnx2_rx_int(bp, budget - work_done); 2662 work_done += bnx2_rx_int(bp, budget - work_done);
2660 2663
2661 return work_done; 2664 return work_done;
@@ -4177,7 +4180,6 @@ bnx2_init_rx_ring(struct bnx2 *bp)
4177 4180
4178 ring_prod = prod = bp->rx_prod = 0; 4181 ring_prod = prod = bp->rx_prod = 0;
4179 bp->rx_cons = 0; 4182 bp->rx_cons = 0;
4180 bp->hw_rx_cons = 0;
4181 bp->rx_prod_bseq = 0; 4183 bp->rx_prod_bseq = 0;
4182 4184
4183 for (i = 0; i < bp->rx_max_ring; i++) { 4185 for (i = 0; i < bp->rx_max_ring; i++) {