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

Greg Kroah-Hartman
2018-11-08T22:03:23Z

[ 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.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