[U-Boot] [PATCH v3 5/5] net/designware: Make DMA burst length configurable and reduce by default

[Ian Campbell]

The correct value for this setting can vary across SoCs and boards, so make it
configurable.

Also reduce the default value to 8, which is the same default as used in the
Linux driver.

Signed-off-by: Ian Campbell <ijc at hellion.org.uk>
Cc: Alexey Brodkin <abrodkin at synopsys.com>
---
v3: Pulled into this series instead of sunxi series.
---
 drivers/net/designware.c |  2 +-
 drivers/net/designware.h | 12 ++++++------
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/net/designware.c b/drivers/net/designware.c
index fa816bf..7186e3b 100644
--- a/drivers/net/designware.c
+++ b/drivers/net/designware.c
@@ -249,7 +249,7 @@ static int dw_eth_init(struct eth_device *dev, bd_t *bis)
 	rx_descs_init(dev);
 	tx_descs_init(dev);
 
-	writel(FIXEDBURST | PRIORXTX_41 | BURST_16, &dma_p->busmode);
+	writel(FIXEDBURST | PRIORXTX_41 | DMA_PBL, &dma_p->busmode);
 
 	writel(readl(&dma_p->opmode) | FLUSHTXFIFO | STOREFORWARD,
 	       &dma_p->opmode);
diff --git a/drivers/net/designware.h b/drivers/net/designware.h
index eac5e72..e5b5e20 100644
--- a/drivers/net/designware.h
+++ b/drivers/net/designware.h
@@ -77,18 +77,18 @@ struct eth_dma_regs {
 
 #define DW_DMA_BASE_OFFSET	(0x1000)
 
+/* Default DMA Burst length */
+#ifndef CONFIG_DW_GMAC_DEFAULT_DMA_PBL
+#define CONFIG_DW_GMAC_DEFAULT_DMA_PBL 8
+#endif
+
 /* Bus mode register definitions */
 #define FIXEDBURST		(1 << 16)
 #define PRIORXTX_41		(3 << 14)
 #define PRIORXTX_31		(2 << 14)
 #define PRIORXTX_21		(1 << 14)
 #define PRIORXTX_11		(0 << 14)
-#define BURST_1			(1 << 8)
-#define BURST_2			(2 << 8)
-#define BURST_4			(4 << 8)
-#define BURST_8			(8 << 8)
-#define BURST_16		(16 << 8)
-#define BURST_32		(32 << 8)
+#define DMA_PBL			(CONFIG_DW_GMAC_DEFAULT_DMA_PBL<<8)
 #define RXHIGHPRIO		(1 << 1)
 #define DMAMAC_SRST		(1 << 0)
 
-- 
1.9.0