From: maowenan <redacted>
Sent: Thursday, October 25, 2018 8:16 PM

Hi，

After I update version of bnx2 driver from 2.2.1 to 2.2.6, I find BCM5716
sporadically drops packets, which shows in rx_fw_discards.
C36-141-5:~ #  ethtool -S NIC0

NIC statistics:
    rx_ucast_packets: 11902

    rx_mcast_packets: 217

    rx_bcast_packets: 4954320

    rx_filtered_packets: 328793

    rx_fw_discards: 2742

C36-141-5:~ #

5s later:

C36-141-5:~ #  ethtool -S NIC0

NIC statistics:
    rx_ucast_packets: 11910

    rx_mcast_packets: 217

    rx_bcast_packets: 4958117

    rx_filtered_packets: 328897

    rx_fw_discards: 2750

C36-141-5:~ #

so rx_fw_discards: 2742-----> rx_fw_discards: 2750, lost 8 packets.

the information of bnx2
C36-141-5:~ # modinfo bnx2
kernel/drivers/net/ethernet/broadcom/bnx2.ko

firmware:       bnx2/bnx2-rv2p-09ax-6.0.17.fw

firmware:       bnx2/bnx2-rv2p-09-6.0.17.fw

firmware:       bnx2/bnx2-mips-09-6.2.1b.fw

firmware:       bnx2/bnx2-rv2p-06-6.0.15.fw

firmware:       bnx2/bnx2-mips-06-6.2.3.fw
version:        2.2.6


1) Firstly, I check the patches from 2.2.1 to 2.2.6, below patch is interesting.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id
=0021850d0417a4dc38ed871d929b651b87e2ead9
Do not enable filter SORT MODE in chip init routine. This patch addresses an
issue where BCM5716 sporadically drops packets when changing multicast list.

diff --git a/drivers/net/ethernet/broadcom/bnx2.c

b/drivers/net/ethernet/broadcom/bnx2.c
index 8957eb5f4478..8c9a8b7787d2 100644

--- a/drivers/net/ethernet/broadcom/bnx2.c
+++ b/drivers/net/ethernet/broadcom/bnx2.c

@@ -4984,8 +4984,6 @@ bnx2_init_chip(struct bnx2 *bp)

       bp->idle_chk_status_idx = 0xffff;

-       bp->rx_mode = BNX2_EMAC_RX_MODE_SORT_MODE;
-
       /* Set up how to generate a link change interrupt. */
       BNX2_WR(bp, BNX2_EMAC_ATTENTION_ENA,

BNX2_EMAC_ATTENTION_ENA_LINK);


2) Secondly, I revert this patch, after verify it, I find rx_fw_discards does not
increasing.
so I think this patch can fix current issue. But I'm not sure the issue of this
patch to fix will be reproduced?
I'm not convinced that what factor will trigger rx_fw_discards increasing?
And how to fix this?