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| author | Zumeng Chen <zumeng.chen@windriver.com> | 2016-11-28 21:55:00 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-11-29 20:33:55 -0500 |
| commit | ffac0e967f20b7637936dbaa21df08c55f672604 (patch) | |
| tree | 0b79a616d557f4646a717cebc75911a3803670bf /drivers | |
| parent | a0b44eea372b449ef9744fb1d90491cc063289b8 (diff) | |
| download | linux-stable-ffac0e967f20b7637936dbaa21df08c55f672604.tar.gz linux-stable-ffac0e967f20b7637936dbaa21df08c55f672604.tar.bz2 linux-stable-ffac0e967f20b7637936dbaa21df08c55f672604.zip | |
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')
| -rw-r--r-- | drivers/net/ethernet/cadence/macb.c | 2 |
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)); } |