usb: typec: ucsi: acpi: Check the _DEP dependencies

commit 1f3546ff3f0a1000971daef58406954bad3f7061 upstream.

Failing probe with -EPROBE_DEFER until all dependencies
listed in the _DEP (Operation Region Dependencies) object
have been met.

This will fix an issue where on some platforms UCSI ACPI
driver fails to probe because the address space handler for
the operation region that the UCSI ACPI interface uses has
not been loaded yet.

Fixes: 8243edf44152 ("usb: typec: ucsi: Add ACPI driver")
Cc: stable@vger.kernel.org
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20200904110918.51546-1-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/typec/ucsi/ucsi_acpi.c b/drivers/usb/typec/ucsi/ucsi_acpi.c
index 494d2a49203a9528847ebebdcd4c09d171f7abfc..d5e17dd6773a26a2d6acdf0e08214fffe69f44a0 100644 (file)
--- a/drivers/usb/typec/ucsi/ucsi_acpi.c
+++ b/drivers/usb/typec/ucsi/ucsi_acpi.c
@@ -67,11 +67,15 @@ static void ucsi_acpi_notify(acpi_handle handle, u32 event, void *data)
 
 static int ucsi_acpi_probe(struct platform_device *pdev)
 {
+       struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
        struct ucsi_acpi *ua;
        struct resource *res;
        acpi_status status;
        int ret;
 
+       if (adev->dep_unmet)
+               return -EPROBE_DEFER;
+
        ua = devm_kzalloc(&pdev->dev, sizeof(*ua), GFP_KERNEL);
        if (!ua)
                return -ENOMEM;