Public bug reported:

ARM systems that use a GICv3 controller require ITS support to route Message 
Signal Interrupts (MSI) to CPUs. This currently does not work on systems in 
ACPI mode. Most (all?) upcoming server SoCs will be using ACPI-enabled firmware 
as dictated by the ARM Server Base System Architecture specification.

[Test Case]
Boot such a system and look for ITS boot messages and ITS-MSI entries in 

[Regression Risk]
The required patches are currently in linux-next, so we should have upstream 
support for issues. There are a couple 1-liner changes to arch-generic code 
(drivers/acpi/bus.c, drivers/pci/msi.c) to enable this probing, but it is - IMO 
- straightforward and obviously correct.

The bulk of the changes are to ARM-specific code (irq-gic-v3* drivers).
I have regression tested on X-Gene (no GICv3 ITS) and Cavium Thunder-X
(w/ GICv3 ITS) in the currently certified DTB modes.

** Affects: linux (Ubuntu)
     Importance: High
     Assignee: dann frazier (dannf)
         Status: In Progress

You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.

  Support ARM GIC ITS in ACPI mode

To manage notifications about this bug go to:

ubuntu-bugs mailing list

Reply via email to