[PATCH net 0/3] net: stmmac: deliver frames with Rx checksum errors to the stack

[Grische <opensource@grische.xyz>]

On dwmac1000 the MAC drops every frame that fails Rx checksum validation
before the driver sees it. The enhanced descriptor parser would discard
such a frame even if the MAC delivered it. As a result, a VXLAN tunnel
over IPv6 with zero UDP checksums receives nothing while Rx checksum
offload is on, and neither rx_dropped nor rx_errors shows the loss.
Patches 2 and 3 deliver these frames with CHECKSUM_NONE instead, as
commit fe4042797651 ("net: stmmac: dwmac4: stop hardware from dropping
checksum-error packets") did for dwmac4.

Patch 1 makes the AF_XDP zero-copy Rx path honour the checksum error
status. That path already receives such frames on dwmac4, and patches
2 and 3 make them reach it on dwmac1000 as well.

Tested on an Aruba AP-325 (ipq806x-gmac-dwmac) on the net tree, with
and without the series.

Not tested:

- Patch 1 was only compile-tested, as an AF_XDP zero-copy setup was not
  available.
- dwmac-loongson, which also uses dwmac1000_dma_ops.

Grische (3):
  net: stmmac: honour Rx checksum errors in the AF_XDP zero-copy path
  net: stmmac: dwmac1000: don't discard frames with only a checksum
    error
  net: stmmac: dwmac1000: stop hardware from dropping checksum-error
    packets

 drivers/net/ethernet/stmicro/stmmac/dwmac1000.h     | 1 +
 drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c | 2 ++
 drivers/net/ethernet/stmicro/stmmac/enh_desc.c      | 9 +++++----
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c   | 8 +++++---
 4 files changed, 13 insertions(+), 7 deletions(-)


base-commit: 6dc989ea46b96ce170840174b4a38c4a387fb005
-- 
2.54.0