Messages in this thread | | | From | Cristian Marussi <> | Subject | [PATCH 0/9] Rework SCMI initialization and probing sequence | Date | Thu, 22 Dec 2022 18:50:40 +0000 |
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Hi,
under some configurations the SCMI core stack, which is now initialized as a whole at the subsys_initcall level, can be dependent on some other Kernel subsystems (like TEE) when some SCMI transport backend like optee is used.
This has been reported to lead to some awkward probe loop which, even though successful at the end, leaves a track of errors in the logs coming directly from the core Linux driver model facilities.
In order to solve this issue and cleaning up a bit the SCMI stack startup sequence, this small series reviews and reworks the SCMI core stack initialization and probe logic.
Basically the SCMI Bus is split into its own module (scmi-core.ko) which is initialized at subsys_initcall, while the SCMI core stack, including its various transport backends (like optee, mailbox, virtio, smc), is kept into a distinct module (scmi-module.ko) which get initialized at module_init.
The SCMI driver users initlevel, instead, remains unchanged at module_init.
No change is made to the Kconfig: the main ARM_SCMI_PROTOCOL option will now cause both modules to be built.
This allows the other possibly needed subsystems to be up and running well before the core SCMI stack and its dependent transport backends, so solving the reported issue.
Tested with SCMI transports mailbox/virtio and, in a previous draft, optee, in a number of different load/unload/bind/unbind combinations both as builtin and as LKMs.
Applies on v6.1.
Any feedback, testing welcome.
Thanks, Cristian
Cristian Marussi (9): firmware: arm_scmi: Simplify chan_available transport operation firmware: arm_scmi: Use dedicated devices to initialize channels firmware: arm_scmi: Move protocol registration helpers firmware: arm_scmi: Add common notifier helpers firmware: arm_scmi: Refactor protocol device creation firmware: arm_scmi: Move handle get/set helpers firmware: arm_scmi: Refactor device create/destroy helpers firmware: arm_scmi: Introduce a new lifecycle for protocol devices firmware: arm_scmi: Split bus and driver into distinct modules
drivers/firmware/arm_scmi/Makefile | 8 +- drivers/firmware/arm_scmi/bus.c | 388 ++++++++++++----- drivers/firmware/arm_scmi/common.h | 25 +- drivers/firmware/arm_scmi/driver.c | 623 ++++++++++++++-------------- drivers/firmware/arm_scmi/mailbox.c | 6 +- drivers/firmware/arm_scmi/optee.c | 6 +- drivers/firmware/arm_scmi/smc.c | 6 +- drivers/firmware/arm_scmi/virtio.c | 4 +- include/linux/scmi_protocol.h | 5 - 9 files changed, 622 insertions(+), 449 deletions(-)
-- 2.34.1
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