Commit 989316dd authored by Auke Kok's avatar Auke Kok Committed by Auke Kok
Browse files

ixgb: revert an unwanted fix regarding tso/descriptors 



There seemed to be another bug introduced as well as a performance hit
with the addtion of the sentinel descriptor workaround.  Removal of
this workaround appears to prevent the hang.  We'll take a risk
and remove it, as we had never seen the originally reported bug
under linux.

Signed-off-by: default avatarJesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: default avatarAuke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: default avatarJohn Ronciak <john.ronciak@intel.com>
parent 8556f0d1

drivers/net/ixgb/ixgb_main.c

+1 −14
Original line number Diff line number Diff line
@@ -1295,7 +1295,6 @@ ixgb_tx_map(struct ixgb_adapter *adapter, struct sk_buff *skb, 
	struct ixgb_buffer *buffer_info;

	int len = skb->len;

	unsigned int offset = 0, size, count = 0, i;

	unsigned int mss = skb_shinfo(skb)->tso_size;



	unsigned int nr_frags = skb_shinfo(skb)->nr_frags;

	unsigned int f;
@@ -1307,11 +1306,6 @@ ixgb_tx_map(struct ixgb_adapter *adapter, struct sk_buff *skb, 
	while(len) {

		buffer_info = &tx_ring->buffer_info[i];

		size = min(len, IXGB_MAX_JUMBO_FRAME_SIZE);

		/* Workaround for premature desc write-backs

		 * in TSO mode.  Append 4-byte sentinel desc */

		if(unlikely(mss && !nr_frags && size == len && size > 8))

			size -= 4;



		buffer_info->length = size;

		buffer_info->dma =

			pci_map_single(adapter->pdev,
@@ -1337,12 +1331,6 @@ ixgb_tx_map(struct ixgb_adapter *adapter, struct sk_buff *skb, 
		while(len) {

			buffer_info = &tx_ring->buffer_info[i];

			size = min(len, IXGB_MAX_JUMBO_FRAME_SIZE);

			/* Workaround for premature desc write-backs

			 * in TSO mode.  Append 4-byte sentinel desc */

			if(unlikely(mss && (f == (nr_frags-1)) && (size == len)

			            && (size > 8)))

				size -= 4;



			buffer_info->length = size;

			buffer_info->dma =

				pci_map_page(adapter->pdev,
@@ -1421,8 +1409,7 @@ ixgb_tx_queue(struct ixgb_adapter *adapter, int count, int vlan_id,int tx_flags) 
#define TXD_USE_COUNT(S) (((S) >> IXGB_MAX_TXD_PWR) + \

			 (((S) & (IXGB_MAX_DATA_PER_TXD - 1)) ? 1 : 0))

#define DESC_NEEDED TXD_USE_COUNT(IXGB_MAX_DATA_PER_TXD) + \

	MAX_SKB_FRAGS * TXD_USE_COUNT(PAGE_SIZE) + 1 \

	/* one more for TSO workaround */ + 1

	MAX_SKB_FRAGS * TXD_USE_COUNT(PAGE_SIZE) + 1



static int

ixgb_xmit_frame(struct sk_buff *skb, struct net_device *netdev)

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