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Commit 015dac88 authored by Michael Hennerich's avatar Michael Hennerich Committed by David S. Miller
Browse files

netdev: bfin_mac: fix performance issue found by netperf 



- Remove dead long delay
- Use proper defines
- Remove broken implementation of the TX DMA Data Alignment TXDWA feature

Signed-off-by: default avatarMichael Hennerich <michael.hennerich@analog.com>
Signed-off-by: default avatarMike Frysinger <vapier@gentoo.org>
Signed-off-by: default avatarBryan Wu <cooloney@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 805a8ab3

drivers/net/bfin_mac.c

+26 −84
Original line number Diff line number Diff line
@@ -194,13 +194,13 @@ static int desc_list_init(void) 
		struct dma_descriptor *b = &(r->desc_b);



		/* allocate a new skb for next time receive */

		new_skb = dev_alloc_skb(PKT_BUF_SZ + 2);

		new_skb = dev_alloc_skb(PKT_BUF_SZ + NET_IP_ALIGN);

		if (!new_skb) {

			printk(KERN_NOTICE DRV_NAME

			       ": init: low on mem - packet dropped\n");

			goto init_error;

		}

		skb_reserve(new_skb, 2);

		skb_reserve(new_skb, NET_IP_ALIGN);

		r->skb = new_skb;



		/*
@@ -566,9 +566,9 @@ static void adjust_tx_list(void) 
	 */

	if (current_tx_ptr->next->next == tx_list_head) {

		while (tx_list_head->status.status_word == 0) {

			mdelay(1);

			udelay(10);

			if (tx_list_head->status.status_word != 0

			    || !(bfin_read_DMA2_IRQ_STATUS() & 0x08)) {

			    || !(bfin_read_DMA2_IRQ_STATUS() & DMA_RUN)) {

				goto adjust_head;

			}

			if (timeout_cnt-- < 0) {
@@ -606,18 +606,9 @@ static int bfin_mac_hard_start_xmit(struct sk_buff *skb, 
				struct net_device *dev)

{

	u16 *data;



	u32 data_align = (unsigned long)(skb->data) & 0x3;

	current_tx_ptr->skb = skb;



	if (ANOMALY_05000285) {

		/*

		 * TXDWA feature is not avaible to older revision < 0.3 silicon

		 * of BF537

		 *

		 * Only if data buffer is ODD WORD alignment, we do not

		 * need to memcpy

		 */

		u32 data_align = (u32)(skb->data) & 0x3;

	if (data_align == 0x2) {

		/* move skb->data to current_tx_ptr payload */

		data = (u16 *)(skb->data) - 1;
@@ -638,55 +629,6 @@ static int bfin_mac_hard_start_xmit(struct sk_buff *skb, 
			(u32)current_tx_ptr->packet,

			(u32)(current_tx_ptr->packet + skb->len + 2));

	}

	} else {

		/*

		 * TXDWA feature is avaible to revision < 0.3 silicon of

		 * BF537 and always avaible to BF52x

		 */

		u32 data_align = (u32)(skb->data) & 0x3;

		if (data_align == 0x0) {

			u16 sysctl = bfin_read_EMAC_SYSCTL();

			sysctl |= TXDWA;

			bfin_write_EMAC_SYSCTL(sysctl);



			/* move skb->data to current_tx_ptr payload */

			data = (u16 *)(skb->data) - 2;

			*data = (u16)(skb->len);

			current_tx_ptr->desc_a.start_addr = (u32)data;

			/* this is important! */

			blackfin_dcache_flush_range(

					(u32)data,

					(u32)((u8 *)data + skb->len + 4));

		} else if (data_align == 0x2) {

			u16 sysctl = bfin_read_EMAC_SYSCTL();

			sysctl &= ~TXDWA;

			bfin_write_EMAC_SYSCTL(sysctl);



			/* move skb->data to current_tx_ptr payload */

			data = (u16 *)(skb->data) - 1;

			*data = (u16)(skb->len);

			current_tx_ptr->desc_a.start_addr = (u32)data;

			/* this is important! */

			blackfin_dcache_flush_range(

					(u32)data,

					(u32)((u8 *)data + skb->len + 4));

		} else {

			u16 sysctl = bfin_read_EMAC_SYSCTL();

			sysctl &= ~TXDWA;

			bfin_write_EMAC_SYSCTL(sysctl);



			*((u16 *)(current_tx_ptr->packet)) = (u16)(skb->len);

			memcpy((u8 *)(current_tx_ptr->packet + 2), skb->data,

				skb->len);

			current_tx_ptr->desc_a.start_addr =

				(u32)current_tx_ptr->packet;

			if (current_tx_ptr->status.status_word != 0)

				current_tx_ptr->status.status_word = 0;

			blackfin_dcache_flush_range(

				(u32)current_tx_ptr->packet,

				(u32)(current_tx_ptr->packet + skb->len + 2));

		}

	}



	/* make sure the internal data buffers in the core are drained

	 * so that the DMA descriptors are completely written when the
@@ -698,7 +640,7 @@ static int bfin_mac_hard_start_xmit(struct sk_buff *skb, 
	current_tx_ptr->desc_a.config |= DMAEN;



	/* tx dma is running, just return */

	if (bfin_read_DMA2_IRQ_STATUS() & 0x08)

	if (bfin_read_DMA2_IRQ_STATUS() & DMA_RUN)

		goto out;



	/* tx dma is not running */
@@ -724,7 +666,7 @@ static void bfin_mac_rx(struct net_device *dev) 


	/* allocate a new skb for next time receive */

	skb = current_rx_ptr->skb;

	new_skb = dev_alloc_skb(PKT_BUF_SZ + 2);

	new_skb = dev_alloc_skb(PKT_BUF_SZ + NET_IP_ALIGN);

	if (!new_skb) {

		printk(KERN_NOTICE DRV_NAME

		       ": rx: low on mem - packet dropped\n");
@@ -732,7 +674,7 @@ static void bfin_mac_rx(struct net_device *dev) 
		goto out;

	}

	/* reserve 2 bytes for RXDWA padding */

	skb_reserve(new_skb, 2);

	skb_reserve(new_skb, NET_IP_ALIGN);

	current_rx_ptr->skb = new_skb;

	current_rx_ptr->desc_a.start_addr = (unsigned long)new_skb->data - 2;