[PATCH AUTOSEL 4.9 11/38] net: macb: Clean 64b dma addresses if they are not detected

From: Sasha Levin
Date: Tue Oct 16 2018 - 00:22:26 EST

From: Michal Simek <michal.simek@xxxxxxxxxx>

[ 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 2e1585635083..515b53ef39ed 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)
dmacfg &= ~GEM_BIT(TXCOEN);

+ dmacfg &= ~GEM_BIT(ADDR64);
dmacfg |= GEM_BIT(ADDR64);