[PATCH] net: dnet: fix dnet_poll()

[PATCH] net: dnet: fix dnet_poll()

[Eric Dumazet]

From: Eric Dumazet <edumazet@google.com>

A NAPI poll() handler is supposed to return exactly the budget when/if
napi_complete() has not been called.

It is also supposed to return number of frames that were received, so
that netdev_budget can have a meaning.

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
Note : Untested patch, but this driver seems pretty buggy, not sure if
anyone uses it.

 drivers/net/ethernet/dnet.c |   18 +++++-------------
 1 file changed, 5 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/dnet.c b/drivers/net/ethernet/dnet.c
index a379c3e4b57f..13d00a38a5bd 100644
--- a/drivers/net/ethernet/dnet.c
+++ b/drivers/net/ethernet/dnet.c
@@ -398,13 +398,8 @@ static int dnet_poll(struct napi_struct *napi, int budget)
 		 * break out of while loop if there are no more
 		 * packets waiting
 		 */
-		if (!(dnet_readl(bp, RX_FIFO_WCNT) >> 16)) {
-			napi_complete(napi);
-			int_enable = dnet_readl(bp, INTR_ENB);
-			int_enable |= DNET_INTR_SRC_RX_CMDFIFOAF;
-			dnet_writel(bp, int_enable, INTR_ENB);
-			return 0;
-		}
+		if (!(dnet_readl(bp, RX_FIFO_WCNT) >> 16))
+			break;
 
 		cmd_word = dnet_readl(bp, RX_LEN_FIFO);
 		pkt_len = cmd_word & 0xFFFF;
@@ -433,20 +428,17 @@ static int dnet_poll(struct napi_struct *napi, int budget)
 			       "size %u.\n", dev->name, pkt_len);
 	}
 
-	budget -= npackets;
-
 	if (npackets < budget) {
 		/* We processed all packets available.  Tell NAPI it can
-		 * stop polling then re-enable rx interrupts */
+		 * stop polling then re-enable rx interrupts.
+		 */
 		napi_complete(napi);
 		int_enable = dnet_readl(bp, INTR_ENB);
 		int_enable |= DNET_INTR_SRC_RX_CMDFIFOAF;
 		dnet_writel(bp, int_enable, INTR_ENB);
-		return 0;
 	}
 
-	/* There are still packets waiting */
-	return 1;
+	return npackets;
 }
 
 static irqreturn_t dnet_interrupt(int irq, void *dev_id)

Re: [PATCH] net: dnet: fix dnet_poll()

[David Miller]

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Sun, 11 Jan 2015 11:02:32 -0800

> From: Eric Dumazet <edumazet@google.com>
> 
> A NAPI poll() handler is supposed to return exactly the budget when/if
> napi_complete() has not been called.
> 
> It is also supposed to return number of frames that were received, so
> that netdev_budget can have a meaning.
> 
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Applied, thanks Eric.