From dddd406d9dbe4a94919b377a84b696e97f709379 Mon Sep 17 00:00:00 2001 From: Jesse Brandeburg Date: Wed, 27 Jul 2022 09:24:05 +0200 Subject: ice: Implement control of FCS/CRC stripping The driver can allow the user to configure whether the CRC aka the FCS (Frame Check Sequence) is DMA'd to the host as part of the receive buffer. The driver usually wants this feature disabled so that the hardware checks the FCS and strips it in order to save PCI bandwidth. Control the reception of FCS to the host using the command: ethtool -K eth0 rx-fcs The default shown in ethtool -k eth0 | grep fcs; should be "off", as the hardware will drop any frame with a bad checksum, and DMA of the checksum is useless overhead especially for small packets. Testing Hints: test the FCS/CRC arrives with received packets using tcpdump -nnpi eth0 -xxxx and it should show crc data as the last 4 bytes of the packet. Can also use wireshark to turn on CRC checking and check the data is correct. Signed-off-by: Jesse Brandeburg Co-developed-by: Grzegorz Nitka Signed-off-by: Grzegorz Nitka Co-developed-by: Benjamin Mikailenko Signed-off-by: Benjamin Mikailenko Co-developed-by: Anatolii Gerasymenko Signed-off-by: Anatolii Gerasymenko Tested-by: Gurucharan (A Contingent worker at Intel) Signed-off-by: Tony Nguyen --- drivers/net/ethernet/intel/ice/ice_base.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/net/ethernet/intel/ice/ice_base.c') diff --git a/drivers/net/ethernet/intel/ice/ice_base.c b/drivers/net/ethernet/intel/ice/ice_base.c index 136d7911adb4..6f092e06054e 100644 --- a/drivers/net/ethernet/intel/ice/ice_base.c +++ b/drivers/net/ethernet/intel/ice/ice_base.c @@ -417,7 +417,7 @@ static int ice_setup_rx_ctx(struct ice_rx_ring *ring) /* Strip the Ethernet CRC bytes before the packet is posted to host * memory. */ - rlan_ctx.crcstrip = 1; + rlan_ctx.crcstrip = !(ring->flags & ICE_RX_FLAGS_CRC_STRIP_DIS); /* L2TSEL flag defines the reported L2 Tags in the receive descriptor * and it needs to remain 1 for non-DVM capable configurations to not -- cgit v1.2.3