[PATCH] net: sh_eth: Fix RX error handling

[Marek Vasut]

From: Valentine Barshak <valentine.barshak at cogentembedded.com>

In case RX error occurs, and the RD_RFE bit is set, the descriptor
is never returned back to the queue. Make sh_eth_recv_start return
zero length in this case so that the descriptor can be released
and pushed back to the list. Also return the more appropriate
-EAGAIN instead of -EINVAL if the descriptor is not ready yet.

Reviewed-by: Marek Vasut <marek.vasut+renesas at mailbox.org>
Signed-off-by: Valentine Barshak <valentine.barshak at cogentembedded.com>
---
Cc: Joe Hershberger <joe.hershberger at ni.com>
Cc: Ramon Fried <rfried.dev at gmail.com>
---
 drivers/net/sh_eth.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/drivers/net/sh_eth.c b/drivers/net/sh_eth.c
index 8f162ca58fb..da1bc7cb40b 100644
--- a/drivers/net/sh_eth.c
+++ b/drivers/net/sh_eth.c
@@ -129,11 +129,11 @@ static int sh_eth_recv_start(struct sh_eth_dev *eth)
 	/* Check if the rx descriptor is ready */
 	invalidate_cache(port_info->rx_desc_cur, sizeof(struct rx_desc_s));
 	if (port_info->rx_desc_cur->rd0 & RD_RACT)
-		return -EINVAL;
+		return -EAGAIN;
 
 	/* Check for errors */
 	if (port_info->rx_desc_cur->rd0 & RD_RFE)
-		return -EINVAL;
+		return 0;
 
 	return port_info->rx_desc_cur->rd1 & 0xffff;
 }
@@ -555,15 +555,13 @@ static int sh_ether_recv(struct udevice *dev, int flags, uchar **packetp)
 		*packetp = packet;
 
 		return len;
-	} else {
-		len = 0;
+	}
 
-		/* Restart the receiver if disabled */
-		if (!(sh_eth_read(port_info, EDRRR) & EDRRR_R))
-			sh_eth_write(port_info, EDRRR_R, EDRRR);
+	/* Restart the receiver if disabled */
+	if (!(sh_eth_read(port_info, EDRRR) & EDRRR_R))
+		sh_eth_write(port_info, EDRRR_R, EDRRR);
 
-		return -EAGAIN;
-	}
+	return len;
 }
 
 static int sh_ether_free_pkt(struct udevice *dev, uchar *packet, int length)
-- 
2.39.2