[PATCH 3/4] net: designware: Respect "bus mode" register contents on SW reset

[Ian Abbott]

"bus mode" register contains lots of fields and some of them don't
expect to be written with 0 (zero). So since we're only interested in
resetting MAC (which is done with setting the least significant bit of
this register with "0") I believe it's better to modify only 1 bit of
the register.

[Original U-Boot patch by Alexey Brodkin <abrodkin at synopsys.com>]

Signed-off-by: Ian Abbott <abbotti at mev.co.uk>
---
 drivers/net/designware.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/designware.c b/drivers/net/designware.c
index 85e4c58..6702d4c 100644
--- a/drivers/net/designware.c
+++ b/drivers/net/designware.c
@@ -128,7 +128,7 @@ static int mac_reset(struct eth_device *dev)
 	struct eth_dma_regs *dma_p = priv->dma_regs_p;
 	u64 start;
 
-	writel(DMAMAC_SRST, &dma_p->busmode);
+	writel(readl(&dma_p->busmode) | DMAMAC_SRST, &dma_p->busmode);
 
 	if (priv->interface != PHY_INTERFACE_MODE_RGMII)
 		writel(MII_PORTSELECT, &mac_p->conf);
-- 
2.10.1