Re: [PATCH 0/6] fsl-mc: Move fsl_over to device MSI

On Wed, 2026-02-18 at 13:51 +0000, Marc Zyngier wrote:

Over the past few years, I have become increasingly annoyed by this
sort of messages in my boot log:

[    0.067861] fsl-mc MSI: ITS@0x100100040000 domain created
[    0.073352] fsl-mc MSI: ITS@0x100100060000 domain created
[    0.078841] fsl-mc MSI: ITS@0x100100080000 domain created
[    0.084328] fsl-mc MSI: ITS@0x1001000a0000 domain created
[    0.089815] fsl-mc MSI: ITS@0x1001000c0000 domain created
[    0.095303] fsl-mc MSI: ITS@0x1001000e0000 domain created
[    0.100792] fsl-mc MSI: ITS@0x100100100000 domain created
[    0.106281] fsl-mc MSI: ITS@0x100100120000 domain created

While this is useful on fsl-mc systems, this is completely irrelevant
on 99.99999% of the arm64 machines, which know nothing about the
Freescale stuff. Including all of my machine -- bar *one*.

Global MSI domains such as the above have been obsoleted for the past
two years, but nobody at NXP seems to have got the message.

The obvious solution is to delete some code! While my first port of
call would be to just 'git rm -r drivers/bus/fsl-mc' (only kidding!),
a less invasive solution is to drag that code into the present times.
Which is what this series is doing by converting the whole thing to
device MSI, reusing the platform MSI infrastructure instead of
duplicating it.

This results in the expected cleanup, and kills the last user of the
non-device-MSI stuff on arm64. You're welcome.

Marc Zyngier (6):
  fsl-mc: Remove MSI domain propagation to sub-devices
  fsl_mc: Add minimal infrastructure to use platform MSI
  irqchip/gic-v3-its: Add fsl_mc device plumbing to the msi-parent
    handling
  fsl_mc: Switch over to per-device platform MSI
  fsl_mc: Remove legacy MSI implementation
  platform-msi: Remove stale comment

 drivers/base/platform-msi.c                 |   4 -
 drivers/bus/fsl-mc/dprc-driver.c            |  14 +-
 drivers/bus/fsl-mc/fsl-mc-bus.c             |   4 +-
 drivers/bus/fsl-mc/fsl-mc-msi.c             | 142 +++--------------
 drivers/bus/fsl-mc/fsl-mc-private.h         |   2 +-
 drivers/irqchip/Kconfig                     |   6 -
 drivers/irqchip/Makefile                    |   1 -
 drivers/irqchip/irq-gic-its-msi-parent.c    |   7 +-
 drivers/irqchip/irq-gic-v3-its-fsl-mc-msi.c | 168 ------------------
--
 include/linux/fsl/mc.h                      |   6 +-
 10 files changed, 33 insertions(+), 321 deletions(-)
 delete mode 100644 drivers/irqchip/irq-gic-v3-its-fsl-mc-msi.c

I have tested this series (applied to 6.19) with a SolidRun ClearFog CX
LX2 (LX2160A-based), and can confirm that the MSIs are working as I'd
expect them to. Therefore:

Tested-by: Sascha Bischoff <redacted>

Thanks,
Sascha