If a port is powered-off, or in the process of being powered-off, prevent
khubd from operating on it. Otherwise, the following sequence of events
leading to an unintended disconnect may occur:
Events:
(0) <set pm_qos_no_poweroff to '0' for port1>
(1) hub 2-2:1.0: hub_resume
(2) hub 2-2:1.0: port 1: status 0301 change 0000
(3) hub 2-2:1.0: state 7 ports 4 chg 0002 evt 0000
(4) hub 2-2:1.0: port 1, power off status 0000, change 0000, 12 Mb/s
(5) usb 2-2.1: USB disconnect, device number 5
Description:
(1) hub is resumed before sending a ClearPortFeature request
(2) hub_activate() notices the port is connected and sets
hub->change_bits for the port
(3) hub_events() starts, but at the same time the port suspends
(4) hub_connect_change() sees the disabled port and triggers disconnect
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/usb/core/hub.c | 55 ++++++++++++++++++++++++++++--------------------
1 files changed, 32 insertions(+), 23 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 8da2aa706005..0217299a2402 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -4728,32 +4728,41 @@ static void port_event(struct usb_hub *hub, int port1)
USB_PORT_FEAT_C_PORT_CONFIG_ERROR);
}
- if (hub_handle_remote_wakeup(hub, port1, portstatus, portchange))
- connect_change = 1;
-
- /* Warm reset a USB3 protocol port if it's in
- * SS.Inactive state.
- */
- if (hub_port_warm_reset_required(hub, portstatus)) {
- int status;
+ /* take port actions that require the port to be powered on */
+ pm_runtime_get_noresume(&port_dev->dev);
+ pm_runtime_barrier(&port_dev->dev);
+ if (pm_runtime_active(&port_dev->dev)) {
+ if (hub_handle_remote_wakeup(hub, port1,
+ portstatus, portchange))
+ connect_change = 1;
- dev_dbg(hub_dev, "port%d: do warm reset\n", port1);
- if (!udev || !(portstatus & USB_PORT_STAT_CONNECTION)
- || udev->state == USB_STATE_NOTATTACHED) {
- status = hub_port_reset(hub, port1, NULL,
- HUB_BH_RESET_TIME, true);
- if (status < 0)
- hub_port_disable(hub, port1, 1);
- } else {
- usb_lock_device(udev);
- status = usb_reset_device(udev);
- usb_unlock_device(udev);
- connect_change = 0;
+ /* Warm reset a USB3 protocol port if it's in
+ * SS.Inactive state.
+ */
+ if (hub_port_warm_reset_required(hub, portstatus)) {
+ int status;
+
+ dev_dbg(hub_dev, "port%d: do warm reset\n", port1);
+ if (!udev || !(portstatus & USB_PORT_STAT_CONNECTION)
+ || udev->state == USB_STATE_NOTATTACHED) {
+ status = hub_port_reset(hub, port1, NULL,
+ HUB_BH_RESET_TIME,
+ true);
+ if (status < 0)
+ hub_port_disable(hub, port1, 1);
+ } else {
+ usb_lock_device(udev);
+ status = usb_reset_device(udev);
+ usb_unlock_device(udev);
+ connect_change = 0;
+ }
}
- }
- if (connect_change)
- hub_port_connect_change(hub, port1, portstatus, portchange);
+ if (connect_change)
+ hub_port_connect_change(hub, port1,
+ portstatus, portchange);
+ }
+ pm_runtime_put_sync(&port_dev->dev);
}
--
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