Re: [PATCH] net: fec: fix regression on i.MX28 introduced by rx_copybreak support
From: Sergei Shtylyov
Date: Tue Oct 07 2014 - 12:07:14 EST
Hello.
On 10/07/2014 05:19 PM, Lothar WaÃmann wrote:
commit 1b7bde6d659d ("net: fec: implement rx_copybreak to improve rx performance")
introduced a regression for i.MX28. The swap_buffer() function doing
the endian conversion of the received data on i.MX28 may access memory
beyond the actual packet size in the DMA buffer. fec_enet_copybreak()
does not copy those bytes, so that the last bytes of a packet may be
filled with invalid data after swapping.
This will likely lead to checksum errors on received packets.
E.g. when trying to mount an NFS rootfs:
UDP: bad checksum. From 192.168.1.225:111 to 192.168.100.73:44662 ulen 36
Do the byte swapping and copying to the new skb in one go if
necessary.
Signed-off-by: Lothar WaÃmann <LW@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/freescale/fec_main.c | 25 +++++++++++++++++++++----
1 file changed, 21 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 87975b5..eaaebad 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
[...]
@@ -1348,7 +1360,7 @@ fec_enet_new_rxbdp(struct net_device *ndev, struct bufdesc *bdp, struct sk_buff
}
static bool fec_enet_copybreak(struct net_device *ndev, struct sk_buff **skb,
- struct bufdesc *bdp, u32 length)
+ struct bufdesc *bdp, u32 length, int swap)
'bool swap' perhaps?
@@ -1393,6 +1408,7 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
u16 vlan_tag;
int index = 0;
bool is_copybreak;
+ bool need_swap = id_entry->driver_data & FEC_QUIRK_SWAP_FRAME;
... especially talking this into account...
WBR, Sergei
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