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Bruce Allan authored
When the Manageability Engine (ME) is enabled on 82579, it periodically accesses some MAC CSR registers. There is an arbiter in hardware which prevents simultaneous access of these registers by the host software, i.e. the driver. There is a hardware bug in the aribter that signals a host access of the registers later than it actually happens. A write of the Transmit or Receive Descriptor Tail register could result in an incorrect value if the driver and ME perform simultaneous accesses which could result in an access to an invalid memory address. This would return an Unsupported Request which could hang the hardware. Workaround the issue by checking the FWSM register bit24 which is set by ME before it accesses the MAC CSR registers. 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>
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