skiboot 5.1.19 release notes

Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

doc/release-notes/skiboot-5.1.19.txt

@@ -0,0 +1,46 @@
+skiboot-5.1.19
+--------------
+
+skiboot-5.1.19 was released on Monday 16th January 2017.
+
+skiboot-5.1.19 is the 20th stable release of 5.1, it follows skiboot-5.1.18
+(which was released 26th August 2016).
+
+This release contains a few minor bug fixes.
+
+Changes are:
+
+Generic:
+- Makefile: Disable stack protector due to gcc problems
+- stack: Don't recurse into __stack_chk_fail
+- Makefile: Use -ffixed-r13
+  - we did not find evidence of this ever being a problem, but this fix
+    is good and preventative.
+- Limit number of "Poller recursion detected" errors to display
+  In some error conditions, we could spiral out of control on this
+  and spend all of our time printing the exact same backtrace.
+  Limit it to 16 times, because 16 is a nice number.
+
+FSP based Systems:
+- fsp: Don't recurse pollers in ibm_fsp_terminate
+  If we were to terminate in a poller, we'd call op_display() which
+  called pollers which hit the recursive poller warning, which ended
+  in not much fun at all.
+
+PCI:
+- hw/phb3: set PHB retry state correctly when fresetting during a creset
+- phb3: Lock the PHB on set_xive callbacks
+    Those are called by the interrupts core and thus skip the locking
+    implicit in the PCI opal calls.
+- hw/{phb3, p7ioc}: Return success for freset on empty PHB
+  OPAL_CLOSED is returned when fundamental reset is issued on the
+  PHB who doesn't have subordinate devices (root port excluded).
+  The kernel raises an error message, which is unnecessary. This
+  returns OPAL_SUCCESS for this case to avoid the error message.
+- hw/phb3: fix error handling in complete reset
+  During a complete reset, when we get a timeout waiting for pending
+  transaction in state PHB3_STATE_CRESET_WAIT_CQ, we mark the PHB as broken
+  and return OPAL_PARAMETER.
+  Change the return code to OPAL_HARDWARE which is way more sensible, and set
+  the state to PHB3_STATE_FENCED so that the kernel can retry the complete
+  reset.