commit bf25e23d07f16be62825650c0826c4eadf2699b6
author Matt Parrella <parrella.matthew@gmail.com> Tue Mar 14 14:43:19 2023 +0000
committer Michael Brown <mcb30@ipxe.org> Tue Mar 14 14:44:32 2023 +0000
tree 477d472293978b0d41252513b2eec4fbe59db885
parent 8f1c1201199a924eeba31494be5aa6bf13eb3fa0

[intel] Add workaround for I210 reset hardware bugs

The Intel I210's packet buffer size registers reset only on power up,
not when a reset signal is asserted.  This can lead to the inability
to pass traffic in the event that the DMA TX Maximum Packet Size
(which does reset to its default value on reset) is bigger than the TX
Packet Buffer Size.

For example, an operating system may be using the time sensitive
networking features of the I210 and the registers may be programmed
correctly, but then a reset signal is asserted and iPXE on the next
boot will be unable to use the I210.

Mimic what Linux does and forcibly set the registers to their default
values.

Signed-off-by: Matt Parrella <parrella.matthew@gmail.com>