This fixes an issue where the driver fails with an error:
ioremap error for 0x3f799000-0x3f79a000, requested 0x2, got 0x0
On some platforms the UCSI ACPI mailbox SystemMemory Operation Region may be setup before the driver has been loaded. That will lead into the driver failing to map the mailbox region, as it has been already marked as write-back memory. acpi_os_ioremap() for x86 uses ioremap_cache() unconditionally.
When the issue happens, the embedded controller has a pending query event for the UCSI notification right after boot-up which causes the operation region to be setup before UCSI driver has been loaded.
The fix is to notify acpi core that the driver is about to access memory region which potentially overlaps with an operation region right before mapping it. acpi_release_memory() will check if the memory has already been setup (mapped) by acpi core, and deactivate it (unmap) if it has. The driver is then able to map the memory with ioremap_nocache() and set the memtype to uncached for the region.
Reported-by: Paul Menzel pmenzel@molgen.mpg.de Fixes: 8243edf44152 ("usb: typec: ucsi: Add ACPI driver") Cc: stable@vger.kernel.org Signed-off-by: Heikki Krogerus heikki.krogerus@linux.intel.com --- drivers/usb/typec/ucsi/ucsi_acpi.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/usb/typec/ucsi/ucsi_acpi.c b/drivers/usb/typec/ucsi/ucsi_acpi.c index 44eb4e1ea817..a18112a83fae 100644 --- a/drivers/usb/typec/ucsi/ucsi_acpi.c +++ b/drivers/usb/typec/ucsi/ucsi_acpi.c @@ -79,6 +79,11 @@ static int ucsi_acpi_probe(struct platform_device *pdev) return -ENODEV; }
+ /* This will make sure we can use ioremap_nocache() */ + status = acpi_release_memory(ACPI_HANDLE(&pdev->dev), res, 1); + if (ACPI_FAILURE(status)) + return -ENOMEM; + /* * NOTE: The memory region for the data structures is used also in an * operation region, which means ACPI has already reserved it. Therefore