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Commit 36e24e2e authored by Duan Fugang-B38611's avatar Duan Fugang-B38611 Committed by David S. Miller
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net: fec: fix the error to get the previous BD entry 



Bug: error to get the previous BD entry. When the current BD
is the first BD, the previous BD entry must be the last BD,
not "bdp - 1" in current logic.

V4:
  * Optimize fec_enet_get_nextdesc() for code clean.
    Replace "ex_new_bd - ring_size" with "ex_base".
    Replace "new_bd - ring_size" with "base".

V3:
  * Restore the API name because David suggest to use fec_enet_
    prefix for all function in fec driver.
    So, change next_bd() -> fec_enet_get_nextdesc()
        change pre_bd()  -> fec_enet_get_prevdesc()
  * Reduce the two APIs parameters for easy to call.

V2:
  * Add tx_ring_size and rx_ring_size to struct fec_enet_private.
  * Replace api fec_enet_get_nextdesc() with next_bd().
    Replace api fec_enet_get_prevdesc() with pre_bd().

  * Move all ring size check logic to next_bd() and pre_bd(), which
    simplifies the code redundancy.

V1:
  * Add BD ring size check to get the previous BD entry in correctly.

Reviewed-by: default avatarLi Frank <B20596@freescale.com>
Signed-off-by: default avatarFugang Duan <B38611@freescale.com>
Acked-by: default avatarFrank Li <frank.li@freescale.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 639739b5

drivers/net/ethernet/freescale/fec.h

+3 −0
Original line number Diff line number Diff line
@@ -296,6 +296,9 @@ struct fec_enet_private { 
	/* The ring entries to be free()ed */

	struct bufdesc	*dirty_tx;



	unsigned short tx_ring_size;

	unsigned short rx_ring_size;



	struct	platform_device *pdev;



	int	opened;

drivers/net/ethernet/freescale/fec_main.c

+74 −46
Original line number Diff line number Diff line
@@ -239,22 +239,57 @@ MODULE_PARM_DESC(macaddr, "FEC Ethernet MAC address"); 


static int mii_cnt;



static struct bufdesc *fec_enet_get_nextdesc(struct bufdesc *bdp, int is_ex)

static inline

struct bufdesc *fec_enet_get_nextdesc(struct bufdesc *bdp, struct fec_enet_private *fep)

{

	struct bufdesc_ex *ex = (struct bufdesc_ex *)bdp;

	if (is_ex)

		return (struct bufdesc *)(ex + 1);

	struct bufdesc *new_bd = bdp + 1;

	struct bufdesc_ex *ex_new_bd = (struct bufdesc_ex *)bdp + 1;

	struct bufdesc_ex *ex_base;

	struct bufdesc *base;

	int ring_size;



	if (bdp >= fep->tx_bd_base) {

		base = fep->tx_bd_base;

		ring_size = fep->tx_ring_size;

		ex_base = (struct bufdesc_ex *)fep->tx_bd_base;

	} else {

		base = fep->rx_bd_base;

		ring_size = fep->rx_ring_size;

		ex_base = (struct bufdesc_ex *)fep->rx_bd_base;

	}



	if (fep->bufdesc_ex)

		return (struct bufdesc *)((ex_new_bd >= (ex_base + ring_size)) ?

			ex_base : ex_new_bd);

	else

		return bdp + 1;

		return (new_bd >= (base + ring_size)) ?

			base : new_bd;

}



static struct bufdesc *fec_enet_get_prevdesc(struct bufdesc *bdp, int is_ex)

static inline

struct bufdesc *fec_enet_get_prevdesc(struct bufdesc *bdp, struct fec_enet_private *fep)

{

	struct bufdesc_ex *ex = (struct bufdesc_ex *)bdp;

	if (is_ex)

		return (struct bufdesc *)(ex - 1);

	struct bufdesc *new_bd = bdp - 1;

	struct bufdesc_ex *ex_new_bd = (struct bufdesc_ex *)bdp - 1;

	struct bufdesc_ex *ex_base;

	struct bufdesc *base;

	int ring_size;



	if (bdp >= fep->tx_bd_base) {

		base = fep->tx_bd_base;

		ring_size = fep->tx_ring_size;

		ex_base = (struct bufdesc_ex *)fep->tx_bd_base;

	} else {

		base = fep->rx_bd_base;

		ring_size = fep->rx_ring_size;

		ex_base = (struct bufdesc_ex *)fep->rx_bd_base;

	}



	if (fep->bufdesc_ex)

		return (struct bufdesc *)((ex_new_bd < ex_base) ?

			(ex_new_bd + ring_size) : ex_new_bd);

	else

		return bdp - 1;

		return (new_bd < base) ? (new_bd + ring_size) : new_bd;

}



static void *swap_buffer(void *bufaddr, int len)
@@ -380,7 +415,7 @@ fec_enet_start_xmit(struct sk_buff *skb, struct net_device *ndev) 
		}

	}



	bdp_pre = fec_enet_get_prevdesc(bdp, fep->bufdesc_ex);

	bdp_pre = fec_enet_get_prevdesc(bdp, fep);

	if ((id_entry->driver_data & FEC_QUIRK_ERR006358) &&

	    !(bdp_pre->cbd_sc & BD_ENET_TX_READY)) {

		fep->delay_work.trig_tx = true;
@@ -389,10 +424,7 @@ fec_enet_start_xmit(struct sk_buff *skb, struct net_device *ndev) 
	}



	/* If this was the last BD in the ring, start at the beginning again. */

	if (status & BD_ENET_TX_WRAP)

		bdp = fep->tx_bd_base;

	else

		bdp = fec_enet_get_nextdesc(bdp, fep->bufdesc_ex);

	bdp = fec_enet_get_nextdesc(bdp, fep);



	fep->cur_tx = bdp;
@@ -417,18 +449,18 @@ static void fec_enet_bd_init(struct net_device *dev) 


	/* Initialize the receive buffer descriptors. */

	bdp = fep->rx_bd_base;

	for (i = 0; i < RX_RING_SIZE; i++) {

	for (i = 0; i < fep->rx_ring_size; i++) {



		/* Initialize the BD for every fragment in the page. */

		if (bdp->cbd_bufaddr)

			bdp->cbd_sc = BD_ENET_RX_EMPTY;

		else

			bdp->cbd_sc = 0;

		bdp = fec_enet_get_nextdesc(bdp, fep->bufdesc_ex);

		bdp = fec_enet_get_nextdesc(bdp, fep);

	}



	/* Set the last buffer to wrap */

	bdp = fec_enet_get_prevdesc(bdp, fep->bufdesc_ex);

	bdp = fec_enet_get_prevdesc(bdp, fep);

	bdp->cbd_sc |= BD_SC_WRAP;



	fep->cur_rx = fep->rx_bd_base;
@@ -436,7 +468,7 @@ static void fec_enet_bd_init(struct net_device *dev) 
	/* ...and the same for transmit */

	bdp = fep->tx_bd_base;

	fep->cur_tx = bdp;

	for (i = 0; i < TX_RING_SIZE; i++) {

	for (i = 0; i < fep->tx_ring_size; i++) {



		/* Initialize the BD for every fragment in the page. */

		bdp->cbd_sc = 0;
@@ -445,11 +477,11 @@ static void fec_enet_bd_init(struct net_device *dev) 
			fep->tx_skbuff[i] = NULL;

		}

		bdp->cbd_bufaddr = 0;

		bdp = fec_enet_get_nextdesc(bdp, fep->bufdesc_ex);

		bdp = fec_enet_get_nextdesc(bdp, fep);

	}



	/* Set the last buffer to wrap */

	bdp = fec_enet_get_prevdesc(bdp, fep->bufdesc_ex);

	bdp = fec_enet_get_prevdesc(bdp, fep);

	bdp->cbd_sc |= BD_SC_WRAP;

	fep->dirty_tx = bdp;

}
@@ -510,10 +542,10 @@ fec_restart(struct net_device *ndev, int duplex) 
	writel(fep->bd_dma, fep->hwp + FEC_R_DES_START);

	if (fep->bufdesc_ex)

		writel((unsigned long)fep->bd_dma + sizeof(struct bufdesc_ex)

			* RX_RING_SIZE, fep->hwp + FEC_X_DES_START);

			* fep->rx_ring_size, fep->hwp + FEC_X_DES_START);

	else

		writel((unsigned long)fep->bd_dma + sizeof(struct bufdesc)

			* RX_RING_SIZE,	fep->hwp + FEC_X_DES_START);

			* fep->rx_ring_size,	fep->hwp + FEC_X_DES_START);





	for (i = 0; i <= TX_RING_MOD_MASK; i++) {
@@ -727,10 +759,7 @@ fec_enet_tx(struct net_device *ndev) 
	bdp = fep->dirty_tx;



	/* get next bdp of dirty_tx */

	if (bdp->cbd_sc & BD_ENET_TX_WRAP)

		bdp = fep->tx_bd_base;

	else

		bdp = fec_enet_get_nextdesc(bdp, fep->bufdesc_ex);

	bdp = fec_enet_get_nextdesc(bdp, fep);



	while (((status = bdp->cbd_sc) & BD_ENET_TX_READY) == 0) {
@@ -800,10 +829,7 @@ fec_enet_tx(struct net_device *ndev) 
		fep->dirty_tx = bdp;



		/* Update pointer to next buffer descriptor to be transmitted */

		if (status & BD_ENET_TX_WRAP)

			bdp = fep->tx_bd_base;

		else

			bdp = fec_enet_get_nextdesc(bdp, fep->bufdesc_ex);

		bdp = fec_enet_get_nextdesc(bdp, fep);



		/* Since we have freed up a buffer, the ring is no longer full

		 */
@@ -993,10 +1019,8 @@ rx_processing_done: 
		}



		/* Update BD pointer to next entry */

		if (status & BD_ENET_RX_WRAP)

			bdp = fep->rx_bd_base;

		else

			bdp = fec_enet_get_nextdesc(bdp, fep->bufdesc_ex);

		bdp = fec_enet_get_nextdesc(bdp, fep);



		/* Doing this here will keep the FEC running while we process

		 * incoming frames.  On a heavily loaded network, we should be

		 * able to keep up at the expense of system resources.
@@ -1662,7 +1686,7 @@ static void fec_enet_free_buffers(struct net_device *ndev) 
	struct bufdesc	*bdp;



	bdp = fep->rx_bd_base;

	for (i = 0; i < RX_RING_SIZE; i++) {

	for (i = 0; i < fep->rx_ring_size; i++) {

		skb = fep->rx_skbuff[i];



		if (bdp->cbd_bufaddr)
@@ -1670,11 +1694,11 @@ static void fec_enet_free_buffers(struct net_device *ndev) 
					FEC_ENET_RX_FRSIZE, DMA_FROM_DEVICE);

		if (skb)

			dev_kfree_skb(skb);

		bdp = fec_enet_get_nextdesc(bdp, fep->bufdesc_ex);

		bdp = fec_enet_get_nextdesc(bdp, fep);

	}



	bdp = fep->tx_bd_base;

	for (i = 0; i < TX_RING_SIZE; i++)

	for (i = 0; i < fep->tx_ring_size; i++)

		kfree(fep->tx_bounce[i]);

}
@@ -1686,7 +1710,7 @@ static int fec_enet_alloc_buffers(struct net_device *ndev) 
	struct bufdesc	*bdp;



	bdp = fep->rx_bd_base;

	for (i = 0; i < RX_RING_SIZE; i++) {

	for (i = 0; i < fep->rx_ring_size; i++) {

		skb = netdev_alloc_skb(ndev, FEC_ENET_RX_FRSIZE);

		if (!skb) {

			fec_enet_free_buffers(ndev);
@@ -1703,15 +1727,15 @@ static int fec_enet_alloc_buffers(struct net_device *ndev) 
			ebdp->cbd_esc = BD_ENET_RX_INT;

		}



		bdp = fec_enet_get_nextdesc(bdp, fep->bufdesc_ex);

		bdp = fec_enet_get_nextdesc(bdp, fep);

	}



	/* Set the last buffer to wrap. */

	bdp = fec_enet_get_prevdesc(bdp, fep->bufdesc_ex);

	bdp = fec_enet_get_prevdesc(bdp, fep);

	bdp->cbd_sc |= BD_SC_WRAP;



	bdp = fep->tx_bd_base;

	for (i = 0; i < TX_RING_SIZE; i++) {

	for (i = 0; i < fep->tx_ring_size; i++) {

		fep->tx_bounce[i] = kmalloc(FEC_ENET_TX_FRSIZE, GFP_KERNEL);



		bdp->cbd_sc = 0;
@@ -1722,11 +1746,11 @@ static int fec_enet_alloc_buffers(struct net_device *ndev) 
			ebdp->cbd_esc = BD_ENET_TX_INT;

		}



		bdp = fec_enet_get_nextdesc(bdp, fep->bufdesc_ex);

		bdp = fec_enet_get_nextdesc(bdp, fep);

	}



	/* Set the last buffer to wrap. */

	bdp = fec_enet_get_prevdesc(bdp, fep->bufdesc_ex);

	bdp = fec_enet_get_prevdesc(bdp, fep);

	bdp->cbd_sc |= BD_SC_WRAP;



	return 0;
@@ -1966,13 +1990,17 @@ static int fec_enet_init(struct net_device *ndev) 
	/* Get the Ethernet address */

	fec_get_mac(ndev);



	/* init the tx & rx ring size */

	fep->tx_ring_size = TX_RING_SIZE;

	fep->rx_ring_size = RX_RING_SIZE;



	/* Set receive and transmit descriptor base. */

	fep->rx_bd_base = cbd_base;

	if (fep->bufdesc_ex)

		fep->tx_bd_base = (struct bufdesc *)

			(((struct bufdesc_ex *)cbd_base) + RX_RING_SIZE);

			(((struct bufdesc_ex *)cbd_base) + fep->rx_ring_size);

	else

		fep->tx_bd_base = cbd_base + RX_RING_SIZE;

		fep->tx_bd_base = cbd_base + fep->rx_ring_size;



	/* The FEC Ethernet specific entries in the device structure */

	ndev->watchdog_timeo = TX_TIMEOUT;