Per spec: Completion interrupts This transport supports polling or interrupt driven modes of communication. In interrupt mode, when the callee completes processing a message, it raises an interrupt to the caller. Hardware support for completion interrupts is optional. i.MX95 SCMI firmware is fully interrupt driven, so Platform expects completion interrupt for Platform to Agent(P2A) notifictions. Add another optional mailbox channel for Agent to notify Platform that notification message has been accepted After notification channel status become freed, Agent will use the new mailbox channel to send completion interrupt to Platform. Add shmem_channel_intr_enabled to check channel flags. Signed-off-by: Peng Fan <peng.fan@xxxxxxx> --- Peng Fan (2): dt-bindings: firmware: arm,scmi: Support notification completion channel firmware: arm_scmi: mailbox: support P2A channel completion .../devicetree/bindings/firmware/arm,scmi.yaml | 12 +++-- drivers/firmware/arm_scmi/common.h | 1 + drivers/firmware/arm_scmi/mailbox.c | 51 +++++++++++++++++++--- drivers/firmware/arm_scmi/shmem.c | 5 +++ 4 files changed, 59 insertions(+), 10 deletions(-) --- base-commit: 9221b2819b8a4196eecf5476d66201be60fbcf29 change-id: 20240507-scmi-notify-07e87a8b9a23 Best regards, -- Peng Fan <peng.fan@xxxxxxx>