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authorZumeng Chen <zumeng.chen@windriver.com>2016-11-28 21:55:00 +0800
committerDavid S. Miller <davem@davemloft.net>2016-11-29 20:33:55 -0500
commitffac0e967f20b7637936dbaa21df08c55f672604 (patch)
tree0b79a616d557f4646a717cebc75911a3803670bf /drivers/net/ethernet/cadence
parenta0b44eea372b449ef9744fb1d90491cc063289b8 (diff)
downloadlinux-ffac0e967f20b7637936dbaa21df08c55f672604.tar.bz2
net: macb: ensure ordering write to re-enable RX smoothly
When a hardware issue happened as described by inline comments, the register write pattern looks like the following: <write ~MACB_BIT(RE)> + wmb(); <write MACB_BIT(RE)> There might be a memory barrier between these two write operations, so add wmb to ensure an flip from 0 to 1 for NCR. Signed-off-by: Zumeng Chen <zumeng.chen@windriver.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/cadence')
-rw-r--r--drivers/net/ethernet/cadence/macb.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c
index 3ede59c9cae0..ec09fcece711 100644
--- a/drivers/net/ethernet/cadence/macb.c
+++ b/drivers/net/ethernet/cadence/macb.c
@@ -1157,6 +1157,7 @@ static irqreturn_t macb_interrupt(int irq, void *dev_id)
if (status & MACB_BIT(RXUBR)) {
ctrl = macb_readl(bp, NCR);
macb_writel(bp, NCR, ctrl & ~MACB_BIT(RE));
+ wmb();
macb_writel(bp, NCR, ctrl | MACB_BIT(RE));
if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE)
@@ -2769,6 +2770,7 @@ static irqreturn_t at91ether_interrupt(int irq, void *dev_id)
if (intstatus & MACB_BIT(RXUBR)) {
ctl = macb_readl(lp, NCR);
macb_writel(lp, NCR, ctl & ~MACB_BIT(RE));
+ wmb();
macb_writel(lp, NCR, ctl | MACB_BIT(RE));
}