MFC: r336610 (partial), r339207, r339267
- Or in the DMA coalescing Rx threshold so the other bits set in E1000_DMACR remain intact as intended in igb_init_dmac(). [1]
- Fix igb corrupting checksums with BPF and VLAN In stable/11, this merely syncs the code with head as the problem was introduced with r311849 in the latter and then fixed by r339207 with a different approach than the code used pre-r311849 and in stable/11.
- Use mbuf defines to construct csum offload masks rather than literals
MF11: r340148
Don't use 9k jumbo clusters
Reported by: Coverity
CID: 1304929 [1]