[PATCH net 0/2] igb: Fix i210/i211 Rx timestamping loss and packet corruption

[Pascal Kneuper <PKneuper@dspace.de>]

Hi!

This series fixes two issues with i210/i211 hardware Rx timestamping:

Patch 1 fixes a silent fallback to software timestamps. igb_setup_tx_mode()
unconditionally writes RXPBS, clearing CFG_TS_EN on every igb_up() (link
down/up, MTU change, or reset). Unlike other drivers (igc, i40e, ice),
hardware Rx timestamping fails to persist across link changes.

Patch 2 fixes frame corruption when enabling Rx timestamping at runtime.
RXPBS.CFG_TS_EN changes the packet buffer layout. Toggling it while Rx
queues are active creates a race where descriptor status and buffer layout
disagree for in-flight packets, corrupting Ethernet headers and dropping
frames silently. Fix by quiescing the Rx path around the change.

Patch 1 must precede patch 2, as the quiesce cycle in patch 2 invokes
igb_up() and would otherwise trigger the register clobber.

Best,
Pascal

Pascal Kneuper (2):
  igb: Preserve RXPBS.CFG_TS_EN in igb_setup_tx_mode
  igb: Quiesce the receive path before enabling i210 Rx timestamping

 drivers/net/ethernet/intel/igb/igb_main.c |  7 ++++++-
 drivers/net/ethernet/intel/igb/igb_ptp.c  | 17 +++++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

-- 
2.47.3