[PATCH 4.9 011/171] net: macb: Clean 64b dma addresses if they are not detected

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

[ Upstream commit e1e5d8a9fe737d94ccc0ccbaf0c97f69a8f3e000 ]

Clear ADDR64 dma bit in DMACFG register in case that HW_DMA_CAP_64B is
not detected on 64bit system.
The issue was observed when bootloader(u-boot) does not check macb
feature at DCFG6 register (DAW64_OFFSET) and enabling 64bit dma support
by default. Then macb driver is reading DMACFG register back and only
adding 64bit dma configuration but not cleaning it out.

Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx>
Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/ethernet/cadence/macb.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c
index 8f55c23e9821..a0d640243df2 100644
--- a/drivers/net/ethernet/cadence/macb.c
+++ b/drivers/net/ethernet/cadence/macb.c
@@ -1737,6 +1737,7 @@ static void macb_configure_dma(struct macb *bp)
 		else
 			dmacfg &= ~GEM_BIT(TXCOEN);
 
+		dmacfg &= ~GEM_BIT(ADDR64);
 #ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
 		dmacfg |= GEM_BIT(ADDR64);
 #endif
-- 
2.17.1