MFC r233585-233587:

MFC r233585-233587:
r233585:
  Partially revert r223608 and selectively allow microcode loading
  for 82550C.  For 82550 controllers this change restores CPUSaver
  microcode loading.  Due to silicon bug on 82550 and 82550C with
  server extension, these controllers seem to require CPUSaver
  microcode to receive fragmented UDP datagrams.  However the
  microcode shouldn't be used on client featured 82550C as it locks
  up the controller.  In addition, client featured 82550C does not
  have the silicon bug.  Also clear temporary memory used for
  microcode loading since the same memory area is used for other
  commands.
  While I'm here use 82550C in probe message instead of generic
  82550.

  Reported by:	Andreas Longwitz <longwitz <> incore de>
  Tested by:	Andreas Longwitz <longwitz <> incore de>

r233586:
  Load entire EEPROM contents in device attach time and verify
  whether the checksum of EEPROM is valid or not.  Because driver
  heavily relies on EEPROM information when it selectively enables
  features/workarounds, it would be helpful to know whether driver
  sees valid EEPROM.
  While I'm here remove all other EEPROM accesses since the entire
  EEPROM is loaded at device attach time.

r233587:
  Remove unnecessary #if as the software workaround for PCI protocol
  violation should be activated unless the system is cold-booted
  after updating EEPROM.
  The PCI protocol violation happens only when established link is
  10Mbps so the workaround should be updated whenever link state
  change is detected.  Previously the workaround was activated only
  when user checks current media status with ifconfig(8).

git-svn-id: svn://svn.freebsd.org/base/stable/8@234124 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f