Commit 94b16634 authored by Finn Thain's avatar Finn Thain Committed by David S. Miller
Browse files

net/sonic: Improve receive descriptor status flag check 



After sonic_tx_timeout() calls sonic_init(), it can happen that
sonic_rx() will subsequently encounter a receive descriptor with no
flags set. Remove the comment that says that this can't happen.

When giving a receive descriptor to the SONIC, clear the descriptor
status field. That way, any rx descriptor with flags set can only be
a newly received packet.

Don't process a descriptor without the LPKT bit set. The buffer is
still in use by the SONIC.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Tested-by: default avatarStan Johnson <userm57@yahoo.com>
Signed-off-by: default avatarFinn Thain <fthain@telegraphics.com.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent eaabfd19

drivers/net/ethernet/natsemi/sonic.c

+5 −10
Original line number Diff line number Diff line
@@ -434,7 +434,6 @@ static int index_from_addr(struct sonic_local *lp, dma_addr_t addr, 
static void sonic_rx(struct net_device *dev)

{

	struct sonic_local *lp = netdev_priv(dev);

	int status;

	int entry = lp->cur_rx;

	int prev_entry = lp->eol_rx;
@@ -445,9 +444,10 @@ static void sonic_rx(struct net_device *dev) 
		u16 bufadr_l;

		u16 bufadr_h;

		int pkt_len;

		u16 status = sonic_rda_get(dev, entry, SONIC_RD_STATUS);



		status = sonic_rda_get(dev, entry, SONIC_RD_STATUS);

		if (status & SONIC_RCR_PRX) {

		/* If the RD has LPKT set, the chip has finished with the RB */

		if ((status & SONIC_RCR_PRX) && (status & SONIC_RCR_LPKT)) {

			u32 addr = (sonic_rda_get(dev, entry,

						  SONIC_RD_PKTPTR_H) << 16) |

				   sonic_rda_get(dev, entry, SONIC_RD_PKTPTR_L);
@@ -495,10 +495,6 @@ static void sonic_rx(struct net_device *dev) 
			bufadr_h = (unsigned long)new_laddr >> 16;

			sonic_rra_put(dev, i, SONIC_RR_BUFADR_L, bufadr_l);

			sonic_rra_put(dev, i, SONIC_RR_BUFADR_H, bufadr_h);

		} else {

			/* This should only happen, if we enable accepting broken packets. */

		}

		if (status & SONIC_RCR_LPKT) {

			/*

			 * this was the last packet out of the current receive buffer

			 * give the buffer back to the SONIC
@@ -511,12 +507,11 @@ static void sonic_rx(struct net_device *dev) 
					  __func__);

				SONIC_WRITE(SONIC_ISR, SONIC_INT_RBE); /* clear the flag */

			}

		} else

			printk(KERN_ERR "%s: rx desc without RCR_LPKT. Shouldn't happen !?\n",

			     dev->name);

		}

		/*

		 * give back the descriptor

		 */

		sonic_rda_put(dev, entry, SONIC_RD_STATUS, 0);

		sonic_rda_put(dev, entry, SONIC_RD_IN_USE, 1);



		prev_entry = entry;

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