e1000e: 82579 potential system hang on stress when ME enabled

Previously, a workaround was added to address a hardware bug in the
PCIm2PCI arbiter where a write by the driver of the Transmit/Receive
Descriptor Tail register could happen concurrently with a write of any
MAC CSR register by the Manageability Engine (ME) which could cause the
Tail register to have an incorrect value.  The arbiter is supposed to
prevent the concurrent writes but there is a bug that can cause the Host
(driver) access to be acknowledged later than it should.
After further investigation, it was discovered that a driver write access
of any MAC CSR register after being idle for some time can be lost when
ME is accessing a MAC CSR register.  When this happens, no further target
access is claimed by the MAC which could hang the system.
The workaround to check bit 24 in the FWSM register (set only when ME is
accessing a MAC CSR register) and delay for a limited amount of time until
it is cleared is now done for all driver writes of MAC CSR registers on
82579 with ME enabled.  In the rare case when the driver is writing the
Tail register and ME is accessing any MAC CSR register for a duration
longer than the maximum delay, write the register and verify it has the
correct value before continuing, otherwise reset the device.

This patch also moves some pre-existing macros from the hardware-specific
header file to the more appropriate generic driver header file.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

0 files changed, 0 insertions, 0 deletions