Hi, It seems there never were and there never will be actual devices that expose the UCSI ACPI mailbox interface. There are now PD controllers that support the UCSI interface, but they do not use the ACPI mailbox. So there is no point in mapping the mailbox with ioremap(), we can just use memremap(). That should make it possible to also remove the function acpi_release_memory(). That function was only there to make it possible to use ioremap() in the UCSI ACPI driver. thanks, Heikki Krogerus (2): usb: typec: ucsi: acpi: Map the mailbox with memremap() acpi: Remove the helper for deactivating memory region drivers/acpi/osl.c | 86 ------------------------------ drivers/usb/typec/ucsi/ucsi_acpi.c | 19 ++----- include/linux/acpi.h | 3 -- 3 files changed, 4 insertions(+), 104 deletions(-) -- 2.35.1