[PATCH 6.6 224/396] usb: port: Dont try to peer unused USB ports based on location

Greg Kroah-Hartman
2024-04-01T16:47:04Z

From: Mathias Nyman <mathias.nyman@linux.intel.com>

commit 69c63350e573367f9c8594162288cffa8a26d0d1 upstream.

Unused USB ports may have bogus location data in ACPI PLD tables.
This causes port peering failures as these unused USB2 and USB3 ports
location may match.

Due to these failures the driver prints a
"usb: port power management may be unreliable" warning, and
unnecessarily blocks port power off during runtime suspend.

This was debugged on a couple DELL systems where the unused ports
all returned zeroes in their location data.
Similar bugreports exist for other systems.

Don't try to peer or match ports that have connect type set to
USB_PORT_NOT_USED.

Fixes: 3bfd659baec8 ("usb: find internal hub tier mismatch via acpi")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218465
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218486
Tested-by: Paul Menzel <pmenzel@molgen.mpg.de>
Link: https://lore.kernel.org/linux-usb/5406d361-f5b7-4309-b0e6-8c94408f7d75@molgen.mpg.de
Cc: stable@vger.kernel.org # v3.16+
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218490
Link: https://lore.kernel.org/r/20240222233343.71856-1-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/core/port.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

--- a/drivers/usb/core/port.c
+++ b/drivers/usb/core/port.c
@@ -573,7 +573,7 @@ static int match_location(struct usb_dev
struct usb_hub *peer_hub = usb_hub_to_struct_hub(peer_hdev);
struct usb_device *hdev = to_usb_device(port_dev->dev.parent->parent);

- if (!peer_hub)
+ if (!peer_hub || port_dev->connect_type == USB_PORT_NOT_USED)
return 0;

hcd = bus_to_hcd(hdev->bus);
@@ -584,7 +584,8 @@ static int match_location(struct usb_dev

for (port1 = 1; port1 <= peer_hdev->maxchild; port1++) {
peer = peer_hub->ports[port1 - 1];
- if (peer && peer->location == port_dev->location) {
+ if (peer && peer->connect_type != USB_PORT_NOT_USED &&
+ peer->location == port_dev->location) {
link_peers_report(port_dev, peer);
return 1; /* done */
}