On 10/22/2024 07:37, Mathias Nyman wrote:
Fix a boot hang issue triggered when a USB3 device is incorrectly assumed
to be tunneled over USB4, thus attempting to create a device link between
the USB3 "consumer" device and the USB4 "supplier" Host Interface before
the USB4 side is properly bound to a driver.
This could happen if xhci isn't capable of detecting tunneled devices,
but ACPI tables contain all info needed to assume device is tunneled.
i.e. udev->tunnel_mode == USB_LINK_UNKNOWN.
If the USB4 host interface hasn't probed yet, then we know the USB3
device is not in a tunnel created by the USB4 Host Interface driver, so
don't try to create a device link in this case.
cc: Mario Limonciello <mario.limonciello@xxxxxxx>
Fixes: f1bfb4a6fed6 ("usb: acpi: add device link between tunneled USB3 device and USB4 Host Interface")
Tested-by: Harry Wentland <harry.wentland@xxxxxxx>
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
Reviewed-by: Mario Limonciello <mario.limonciello@xxxxxxx>
---
drivers/usb/core/usb-acpi.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/drivers/usb/core/usb-acpi.c b/drivers/usb/core/usb-acpi.c
index 21585ed89ef8..9e1ec71881db 100644
--- a/drivers/usb/core/usb-acpi.c
+++ b/drivers/usb/core/usb-acpi.c
@@ -173,6 +173,17 @@ static int usb_acpi_add_usb4_devlink(struct usb_device *udev)
if (IS_ERR(nhi_fwnode))
return 0;
+ /*
+ * If USB4 Host interface driver isn't set up yet we can't be in a USB3
+ * tunnel created by it.
+ */
+ if (!nhi_fwnode->dev || !device_is_bound(nhi_fwnode->dev)) {
+ dev_info(&port_dev->dev, "%s probed before USB4 host interface\n",
+ dev_name(&port_dev->child->dev));
+ udev->tunnel_mode = USB_LINK_NATIVE;
+ return 0;
+ }
+
link = device_link_add(&port_dev->child->dev, nhi_fwnode->dev,
DL_FLAG_AUTOREMOVE_CONSUMER |
DL_FLAG_RPM_ACTIVE |
