net: davinci_emac: Remove useless dcache ops on descriptors

ATM the rx and tx descriptors are handled as cached memory while they
lie in a dedicated RAM of the SoCs, which is an uncached area.
Removing the said dcache ops, while optimizing the logic and clarifying
the code, also gets rid of most of the check_cache_range() incurred
warnings:
CACHE: Misaligned operation at range
Signed-off-by: NKarl Beldan <karl.beldan+oss@gmail.com>
Acked-by: NJoe Hershberger <joe.hershberger@ni.com>

drivers/net/davinci_emac.c

@@ -108,26 +108,6 @@ static u_int8_t	num_phy;
 
 phy_t				phy[CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT];
 
-static inline void davinci_flush_rx_descs(void)
-{
-	/* flush the whole RX descs area */
-	flush_dcache_range(EMAC_WRAPPER_RAM_ADDR + EMAC_RX_DESC_BASE,
-			EMAC_WRAPPER_RAM_ADDR + EMAC_TX_DESC_BASE);
-}
-
-static inline void davinci_invalidate_rx_descs(void)
-{
-	/* invalidate the whole RX descs area */
-	invalidate_dcache_range(EMAC_WRAPPER_RAM_ADDR + EMAC_RX_DESC_BASE,
-			EMAC_WRAPPER_RAM_ADDR + EMAC_TX_DESC_BASE);
-}
-
-static inline void davinci_flush_desc(emac_desc *desc)
-{
-	flush_dcache_range((unsigned long)desc,
-			(unsigned long)desc + sizeof(*desc));
-}
-
 static int davinci_eth_set_mac_addr(struct eth_device *dev)
 {
 	unsigned long		mac_hi;
@@ -496,8 +476,6 @@ static int davinci_eth_open(struct eth_device *dev, bd_t *bis)
 	emac_rx_active_tail = rx_desc;
 	emac_rx_queue_active = 1;
 
-	davinci_flush_rx_descs();
-
 	/* Enable TX/RX */
 	writel(EMAC_MAX_ETHERNET_PKT_SIZE, &adap_emac->RXMAXLEN);
 	writel(0, &adap_emac->RXBUFFEROFFSET);
@@ -660,7 +638,6 @@ static int davinci_eth_send_packet (struct eth_device *dev,
 
 	flush_dcache_range((unsigned long)packet,
 			(unsigned long)packet + length);
-	davinci_flush_desc(emac_tx_desc);
 
 	/* Send the packet */
 	writel(BD_TO_HW((unsigned long)emac_tx_desc), &adap_emac->TX0HDP);
@@ -694,8 +671,6 @@ static int davinci_eth_rcv_packet (struct eth_device *dev)
 	volatile emac_desc *tail_desc;
 	int status, ret = -1;
 
-	davinci_invalidate_rx_descs();
-
 	rx_curr_desc = emac_rx_active_head;
 	if (!rx_curr_desc)
 		return 0;
@@ -734,7 +709,6 @@ static int davinci_eth_rcv_packet (struct eth_device *dev)
 		rx_curr_desc->buff_off_len = EMAC_MAX_ETHERNET_PKT_SIZE;
 		rx_curr_desc->pkt_flag_len = EMAC_CPPI_OWNERSHIP_BIT;
 		rx_curr_desc->next = 0;
-		davinci_flush_desc(rx_curr_desc);
 
 		if (emac_rx_active_head == 0) {
 			printf ("INFO: emac_rcv_pkt: active queue head = 0\n");
@@ -752,13 +726,11 @@ static int davinci_eth_rcv_packet (struct eth_device *dev)
 			tail_desc->next = BD_TO_HW((ulong) curr_desc);
 			status = tail_desc->pkt_flag_len;
 			if (status & EMAC_CPPI_EOQ_BIT) {
-				davinci_flush_desc(tail_desc);
 				writel(BD_TO_HW((ulong)curr_desc),
 				       &adap_emac->RX0HDP);
 				status &= ~EMAC_CPPI_EOQ_BIT;
 				tail_desc->pkt_flag_len = status;
 			}
-			davinci_flush_desc(tail_desc);
 		}
 		return (ret);
 	}