[PATCH AUTOSEL 4.14 17/61] net: macb: Clean 64b dma addresses if they are not detected

Sasha Levin
2018-10-16T04:26:54Z

From: Michal Simek <michal.simek@xilinx.com>

[ 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@xilinx.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/cadence/macb_main.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index c1787be6a258..aaf450e2ecc5 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -2000,6 +2000,7 @@ static void macb_configure_dma(struct macb *bp)
else
dmacfg &= ~GEM_BIT(TXCOEN);

+ dmacfg &= ~GEM_BIT(ADDR64);
#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
if (bp->hw_dma_cap & HW_DMA_CAP_64B)
dmacfg |= GEM_BIT(ADDR64);
--
2.17.1