e1000e: fix the use of magic numbers for buffer overrun issue

This is a follow on to commit b10effb92e27 ("fix buffer overrun while the
 I219 is processing DMA transactions") to address David Laights concerns
about the use of "magic" numbers.  So define masks as well as add
additional code comments to give a better understanding of what needs to
be done to avoid a buffer overrun.

Signed-off-by: Sasha Neftin <[email protected]>
Reviewed-by: Alexander H Duyck <[email protected]>
Reviewed-by: Dima Ruinskiy <[email protected]>
Reviewed-by: Raanan Avargil <[email protected]>
Tested-by: Aaron Brown <[email protected]>
Signed-off-by: Jeff Kirsher <[email protected]>

0 files changed, 0 insertions, 0 deletions