From 7af9c3a84384b4330ba961ea5bf3a7a79d8ad1f1 Mon Sep 17 00:00:00 2001 From: Christoph Fritz Date: Wed, 30 Apr 2014 10:32:02 +0200 Subject: net cpsw: fix rx stability under heavy network load RX DMA Head Descriptor Pointer can get 0 when there is a lot of traffic, which results in a timeout error. A good way to provoke this error is by sending lots of ARP requests. This patch makes sure that the RX DMA Head Descriptor Pointer is set. The origin driver, from which this is derived, already contains this fix. Signed-off-by: Christoph Fritz Signed-off-by: Sascha Hauer --- drivers/net/cpsw.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'drivers/net/cpsw.c') diff --git a/drivers/net/cpsw.c b/drivers/net/cpsw.c index 52adf50205..ec3263d4aa 100644 --- a/drivers/net/cpsw.c +++ b/drivers/net/cpsw.c @@ -741,8 +741,13 @@ static int cpdma_process(struct cpsw_priv *priv, struct cpdma_chan *chan, if (buffer) *buffer = (void *)readl(&desc->sw_buffer); - if (status & CPDMA_DESC_OWNER) + if (status & CPDMA_DESC_OWNER) { + if (readl(chan->hdp) == 0) { + if (readl(&desc->hw_mode) & CPDMA_DESC_OWNER) + writel((u32)desc, chan->hdp); + } return -EBUSY; + } chan->head = (void *)readl(&desc->hw_next); -- cgit v1.2.3