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| author |   Nathan Sullivan <nathan.sullivan@ni.com> | 2015-05-13 17:01:36 -0500 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2015-05-15 12:13:11 -0400 |
| commit | 86b5e7de07aa1abc87ecc40d2aca6070348e4469 (patch) | |
| tree | f82d533282c5f4038c172be1bad4c5ac24ea858e /drivers/net/ethernet/cadence | |
| parent | rename RTNH_F_EXTERNAL to RTNH_F_OFFLOAD (diff) | |
| download | linux-dev-86b5e7de07aa1abc87ecc40d2aca6070348e4469.tar.xz linux-dev-86b5e7de07aa1abc87ecc40d2aca6070348e4469.zip | |
net: macb: Add better comment for RXUBR handling
Describe the handler for RXUBR better with a new comment.
Signed-off-by: Nathan Sullivan <nathan.sullivan@ni.com>
Reviewied-by: Josh Cartwright <joshc@ni.com>
Reviewied-by: Ben Shelton <ben.shelton@ni.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.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c index 61aa570aad9a..5f10dfc631d7 100644 --- a/drivers/net/ethernet/cadence/macb.c +++ b/drivers/net/ethernet/cadence/macb.c @@ -1037,6 +1037,12 @@ static irqreturn_t macb_interrupt(int irq, void *dev_id) * add that if/when we get our hands on a full-blown MII PHY. */ + /* There is a hardware issue under heavy load where DMA can + * stop, this causes endless "used buffer descriptor read" + * interrupts but it can be cleared by re-enabling RX. See + * the at91 manual, section 41.3.1 or the Zynq manual + * section 16.7.4 for details. + */ if (status & MACB_BIT(RXUBR)) { ctrl = macb_readl(bp, NCR); macb_writel(bp, NCR, ctrl & ~MACB_BIT(RE)); |