Commit 82788c7a authored by Stephen Hemminger's avatar Stephen Hemminger Committed by Jeff Garzik
Browse files

[PATCH] sky2: receive buffer alignment 



Need to make sure that sky2 receive buffers are 64 bit
aligned. Also, don't need to start off with GFP_ATOMIC
on initial setup.

Signed-off-by: default avatarStephen Hemminger <shemminger@osdl.org>
Signed-off-by: default avatarJeff Garzik <jgarzik@pobox.com>
parent 05479938

drivers/net/sky2.c

+23 −7
Original line number Diff line number Diff line
@@ -75,6 +75,7 @@ 
#define RX_LE_BYTES		(RX_LE_SIZE*sizeof(struct sky2_rx_le))

#define RX_MAX_PENDING		(RX_LE_SIZE/2 - 2)

#define RX_DEF_PENDING		RX_MAX_PENDING

#define RX_SKB_ALIGN		8



#define TX_RING_SIZE		512

#define TX_DEF_PENDING		(TX_RING_SIZE - 1)
@@ -904,16 +905,31 @@ static void sky2_vlan_rx_kill_vid(struct net_device *dev, unsigned short vid) 
}

#endif



/*

 * It appears the hardware has a bug in the FIFO logic that

 * cause it to hang if the FIFO gets overrun and the receive buffer

 * is not aligned. ALso alloc_skb() won't align properly if slab

 * debugging is enabled.

 */

static inline struct sk_buff *sky2_alloc_skb(unsigned int size, gfp_t gfp_mask)

{

	struct sk_buff *skb;



	skb = alloc_skb(size + RX_SKB_ALIGN, gfp_mask);

	if (likely(skb)) {

		unsigned long p	= (unsigned long) skb->data;

		skb_reserve(skb,

			((p + RX_SKB_ALIGN - 1) & ~(RX_SKB_ALIGN - 1)) - p);

	}



	return skb;

}



/*

 * Allocate and setup receiver buffer pool.

 * In case of 64 bit dma, there are 2X as many list elements

 * available as ring entries

 * and need to reserve one list element so we don't wrap around.

 *

 * It appears the hardware has a bug in the FIFO logic that

 * cause it to hang if the FIFO gets overrun and the receive buffer

 * is not aligned.  This means we can't use skb_reserve to align

 * the IP header.

 */

static int sky2_rx_start(struct sky2_port *sky2)

{
@@ -929,7 +945,7 @@ static int sky2_rx_start(struct sky2_port *sky2) 
	for (i = 0; i < sky2->rx_pending; i++) {

		struct ring_info *re = sky2->rx_ring + i;



		re->skb = dev_alloc_skb(sky2->rx_bufsize);

		re->skb = sky2_alloc_skb(sky2->rx_bufsize, GFP_KERNEL);

		if (!re->skb)

			goto nomem;
@@ -1713,7 +1729,7 @@ static struct sk_buff *sky2_receive(struct sky2_port *sky2, 
	} else {

		struct sk_buff *nskb;



		nskb = dev_alloc_skb(sky2->rx_bufsize);

		nskb = sky2_alloc_skb(sky2->rx_bufsize, GFP_ATOMIC);

		if (!nskb)

			goto resubmit;