Re: [PATCH v45 0/7] MCTP over PCC

From: Adam Young

Date: Mon Jul 27 2026 - 12:36:47 EST



On 7/21/26 13:52, Adam Young wrote:
From: Linux Bot <linuxbot@xxxxxxxxxxxxxxxxxxx>

THis patch sereis is long lived, and the main
changelog will saty with the MCTP over PCC patch.
Recent changes in AI code review haved shown required
fixes in the PC mailbox layer. The main changes to this
patch series are the addition of those patches.

Adam Young (7):
mailbox/pcc.c: shmem map/unmap startup/teardown
mailbox/pcc.c: ignore errors on type 4 channels.
mailbox/pcc.c: report errors for PCC clients
mailbox/pcc.c: add query channel function
mctp pcc: Implement MCTP over PCC Transport
synchronize IRQ before releasing shared memory
wrap pchan->chan_in_use in READ/WRITE_ONCE

MAINTAINERS | 5 +
drivers/mailbox/pcc.c | 112 ++++++---
drivers/net/mctp/Kconfig | 15 ++
drivers/net/mctp/Makefile | 1 +
drivers/net/mctp/mctp-pcc.c | 466 ++++++++++++++++++++++++++++++++++++
include/acpi/pcc.h | 9 +
6 files changed, 576 insertions(+), 32 deletions(-)
create mode 100644 drivers/net/mctp/mctp-pcc.c


I am seeking feedback from both the PCC and the Networking teams on how to make progress here.  The MCTP Driver can be made functional with no changes to the PCC layer,  but it will have potential race conditions.  Those will not be triggerable on the known hardware.  Can this driver go in as is, and we pursue the PCC fixes afterwards?

If not, the PCC fixes are blocking a driver that has been through a couple years worth of  code review, and should be prioritized. I put them all into this one patch series to simplify my own organization, and to provide a unified narrative for the networking reviewers.  However, the PCC code tends to be reviewed in linux-arm, and this organization is making it harder for people on that team.  I have been missing messages between reviewers.

At this point, I know that at least one of the patches in the PCC portion of this series needs to be rebased upon work by Sudeep Holla and Huisong Li.  I am reluctant to resubmit them right now for feat of generating unnecessary churn.  There code also obviates another patch in this series, which shows that we are addressing similar issues.