Add skiboot-5.1.12 release notesskiboot-5.1.12

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

1 files changed, 44 insertions, 0 deletions

diff --git a/doc/release-notes/skiboot-5.1.12.txt b/doc/release-notes/skiboot-5.1.12.txt
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+skiboot-5.1.12
+--------------
+
+skiboot-5.1.12 was released on Friday December 4th, 2015.
+
+skiboot-5.1.12 is the 13th stable release of 5.1, it follows skiboot-5.1.11
+(which was released November 13th, 2015).
+
+Skiboot 5.1.12 contains bug fixes and a performance improvement.
+
+opal-prd:
+- Display an explict and obvious message if running on a system that does
+  not support opal-prd, such as an IBM FSP based POWER system, where the
+  FSP takes on the role of opal-prd.
+
+pflash:
+- Fix a missing (C) header
+  - cherry-picked from master.
+
+General:
+- Don't link with libgcc
+  - On some toolchains, we don't have libgcc available.
+
+POWER8 PHB (PCIe) specific:
+- hw/phb3: Flush cache line after updating P/Q bits
+    When doing an MSI EOI, we update the P and Q bits in the IVE. That causes
+    the corresponding cache line to be dirty in the L3 which will cause a
+    subsequent update by the PHB (upon recieving the next MSI) to get a few
+    retries until it gets flushed.
+
+    We improve the situation (and thus performance) by doing a dcbf
+    instruction to force a flush of the update we do in SW.
+
+    This improves interrupt performance, reducing latency per interrupt.
+    The improvement will vary by workload.
+
+IBM FSP based machines:
+- FSP: Give up PSI link on shutdown
+  This clears up some erroneous SRCs (error logs) in some situations.
+- Correctly report back Real Time Clock errors to host
+    Under certain rare error conditions, we could return an error code
+    to the host OS that would cause current Linux kernels to get stuck
+    in an infinite loop during boot.
+    This was introduced in skiboot-5.0-rc1.