skiboot-5.1.16 was released on Friday April 29th, 2016.

skiboot-5.1.16 is the 17th stable release of 5.1, it follows skiboot-5.1.15 (which was released March 16th, 2016).

This release contains a few bug fixes and is a recommended upgrade.


PHB3 (all POWER8 platforms)

  • hw/phb3: Ensure PQ bits are cleared in the IVC when masking IRQ When we mask an interrupt, we may race with another interrupt coming in from the hardware. If this occurs, the P and/or Q bit may end up being set but we never EOI/clear them. This could result in a lost interrupt or the next interrupt that comes in after re-enabling never being presented.

    This fixes a bug seen with some CAPI workloads which have lots of interrupt masking at the same time as high interrupt load. The fix is not specific to CAPI though.

  • hw/phb3: Fix potential race in EOI

    When we EOI we need to clear the present (P) bit in the Interrupt Vector Cache (IVC). We must clear P ensuring that any additional interrupts that come in aren’t lost while also maintaining coherency with the Interrupt Vector Table (IVT).

    To do this, the hardware provides a conditional update bit in the IVC. This bit ensures that generation counts between the IVT and the IVC updates are synchronised.

    Unfortunately we never set this the bit to conditionally update the P bit in the IVC based on the generation count. Also, we didn’t set what we wanted the new generation count to be if the update was successful.

FSP platforms

  • OPAL:Handle mbox response with bad status:0x24 during FSP termination OPAL committed a predictive log with SRC BB822411 in some situations.


  • hmi: Fix a bug where partial hmi event was reported to host. This bug fix ensures the CPU PIR is reported correctly:

      [  305.628283] Fatal Hypervisor Maintenance interrupt [Not recovered]
      [  305.628341]  Error detail: Malfunction Alert
      [  305.628388]     HMER: 8040000000000000
    - [  305.628423]      CPU PIR: 00000000
    + [  200.123021]    CPU PIR: 000008e8
      [  305.628458]  [Unit: VSU] Logic core check stop