Messages in this thread Patch in this message | | | From | Nathan Sullivan <> | Subject | [PATCH] net: macb: Add better comment for RXUBR handling | Date | Wed, 13 May 2015 17:01:36 -0500 |
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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> --- drivers/net/ethernet/cadence/macb.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c index 61aa570..5f10dfc 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)); -- 1.7.10.4
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