[Skiboot] skiboot 5.9.7

[Stewart Smith]

skiboot-5.9.7
*************

skiboot 5.9.7 was released on Friday December 22nd, 2017. It replaces
skiboot-5.9.6 as the current stable release in the 5.9.x series.

Over skiboot-5.9.6, we have two bug fixes, they are:

* phb4: Change PCI MMIO timers

  Currently we have a mismatch between the NCU and PCI timers for MMIO
  accesses. The PCI timers must be lower than the NCU timers otherwise
  it may cause checkstops.

  This changes PCI timeouts controlled by skiboot to 33-50ms. It
  should be forwards and backwards compatible with expected hostboot
  changes to the NCU timer.

* p8-i2c: Limit number of retry attempts

  Currently we will attempt to start an I2C transaction until it
  succeeds. In the event that the OCC does not release the lock on an
  I2C bus this results in an async token being held forever and the
  kernel thread that started the transaction will block forever while
  waiting for an async completion message. Fix this by limiting the
  number of attempts to start the transaction.

-- 
Stewart Smith
OPAL Architect, IBM.