Hello!
In e100 driver it seems that the intention was to accept bad frames in
promiscuous mode and loopback mode.
I think this is evident because of the following code in the driver:
if (nic->flags & promiscuous || nic->loopback) {
? ? ? ? ? ? ? ?config->rx_save_bad_frames = 0x1; ? ? ? /* 1=save, 0=discard */
? ? ? ? ? ? ? ?config->rx_discard_short_frames = 0x0; ?/* 1=discard, 0=save */
? ? ? ? ? ? ? ?config->promiscuous_mode = 0x1; ? ? ? ? /* 1=on, 0=off */
? ? ? ?}
However this intention is not really realized because bad frames are
discarded later by SW check.
This patch finally honors the above intention, making the RX code to
let bad frames to pass when the NIC is in promiscuous or loopback
mode.
This helped me a lot to debug an FPGA ethernet core.
Maybe it can be also useful to someone else..
Thanks
Andrea
?--- drivers/net/e100_orig.c ? ? 2011-06-14 23:29:38.322267075 +0200
+++ drivers/net/e100.c ?2011-06-14 23:34:10.700791472 +0200
@@ -1975,7 +1975,8 @@ static int e100_rx_indicate(struct nic *
? ? ? ?skb_put(skb, actual_size);
? ? ? ?skb->protocol = eth_type_trans(skb, nic->netdev);
- ? ? ? if (unlikely(!(rfd_status & cb_ok))) {
+ ? ? ? if (unlikely(!(nic->flags & promiscuous || nic->loopback) &&
+ ? ? ? ? ? !(rfd_status & cb_ok))) {
? ? ? ? ? ? ? ?/* Don't indicate if hardware indicates errors */
? ? ? ? ? ? ? ?dev_kfree_skb_any(skb);
? ? ? ?} else if (actual_size > ETH_DATA_LEN + VLAN_ETH_HLEN) {