in core/hub.c [5185:5418]
static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus,
u16 portchange)
{
int status = -ENODEV;
int i;
unsigned unit_load;
struct usb_device *hdev = hub->hdev;
struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
struct usb_port *port_dev = hub->ports[port1 - 1];
struct usb_device *udev = port_dev->child;
static int unreliable_port = -1;
bool retry_locked;
/* Disconnect any existing devices under this port */
if (udev) {
if (hcd->usb_phy && !hdev->parent)
usb_phy_notify_disconnect(hcd->usb_phy, udev->speed);
usb_disconnect(&port_dev->child);
}
/* We can forget about a "removed" device when there's a physical
* disconnect or the connect status changes.
*/
if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
(portchange & USB_PORT_STAT_C_CONNECTION))
clear_bit(port1, hub->removed_bits);
if (portchange & (USB_PORT_STAT_C_CONNECTION |
USB_PORT_STAT_C_ENABLE)) {
status = hub_port_debounce_be_stable(hub, port1);
if (status < 0) {
if (status != -ENODEV &&
port1 != unreliable_port &&
printk_ratelimit())
dev_err(&port_dev->dev, "connect-debounce failed\n");
portstatus &= ~USB_PORT_STAT_CONNECTION;
unreliable_port = port1;
} else {
portstatus = status;
}
}
/* Return now if debouncing failed or nothing is connected or
* the device was "removed".
*/
if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
test_bit(port1, hub->removed_bits)) {
/*
* maybe switch power back on (e.g. root hub was reset)
* but only if the port isn't owned by someone else.
*/
if (hub_is_port_power_switchable(hub)
&& !port_is_power_on(hub, portstatus)
&& !port_dev->port_owner)
set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
if (portstatus & USB_PORT_STAT_ENABLE)
goto done;
return;
}
if (hub_is_superspeed(hub->hdev))
unit_load = 150;
else
unit_load = 100;
status = 0;
for (i = 0; i < PORT_INIT_TRIES; i++) {
usb_lock_port(port_dev);
mutex_lock(hcd->address0_mutex);
retry_locked = true;
/* reallocate for each attempt, since references
* to the previous one can escape in various ways
*/
udev = usb_alloc_dev(hdev, hdev->bus, port1);
if (!udev) {
dev_err(&port_dev->dev,
"couldn't allocate usb_device\n");
mutex_unlock(hcd->address0_mutex);
usb_unlock_port(port_dev);
goto done;
}
usb_set_device_state(udev, USB_STATE_POWERED);
udev->bus_mA = hub->mA_per_port;
udev->level = hdev->level + 1;
udev->wusb = hub_is_wusb(hub);
/* Devices connected to SuperSpeed hubs are USB 3.0 or later */
if (hub_is_superspeed(hub->hdev))
udev->speed = USB_SPEED_SUPER;
else
udev->speed = USB_SPEED_UNKNOWN;
choose_devnum(udev);
if (udev->devnum <= 0) {
status = -ENOTCONN; /* Don't retry */
goto loop;
}
/* reset (non-USB 3.0 devices) and get descriptor */
status = hub_port_init(hub, udev, port1, i);
if (status < 0)
goto loop;
mutex_unlock(hcd->address0_mutex);
usb_unlock_port(port_dev);
retry_locked = false;
if (udev->quirks & USB_QUIRK_DELAY_INIT)
msleep(2000);
/* consecutive bus-powered hubs aren't reliable; they can
* violate the voltage drop budget. if the new child has
* a "powered" LED, users should notice we didn't enable it
* (without reading syslog), even without per-port LEDs
* on the parent.
*/
if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
&& udev->bus_mA <= unit_load) {
u16 devstat;
status = usb_get_std_status(udev, USB_RECIP_DEVICE, 0,
&devstat);
if (status) {
dev_dbg(&udev->dev, "get status %d ?\n", status);
goto loop_disable;
}
if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
dev_err(&udev->dev,
"can't connect bus-powered hub "
"to this port\n");
if (hub->has_indicators) {
hub->indicator[port1-1] =
INDICATOR_AMBER_BLINK;
queue_delayed_work(
system_power_efficient_wq,
&hub->leds, 0);
}
status = -ENOTCONN; /* Don't retry */
goto loop_disable;
}
}
/* check for devices running slower than they could */
if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
&& udev->speed == USB_SPEED_FULL
&& highspeed_hubs != 0)
check_highspeed(hub, udev, port1);
/* Store the parent's children[] pointer. At this point
* udev becomes globally accessible, although presumably
* no one will look at it until hdev is unlocked.
*/
status = 0;
mutex_lock(&usb_port_peer_mutex);
/* We mustn't add new devices if the parent hub has
* been disconnected; we would race with the
* recursively_mark_NOTATTACHED() routine.
*/
spin_lock_irq(&device_state_lock);
if (hdev->state == USB_STATE_NOTATTACHED)
status = -ENOTCONN;
else
port_dev->child = udev;
spin_unlock_irq(&device_state_lock);
mutex_unlock(&usb_port_peer_mutex);
/* Run it through the hoops (find a driver, etc) */
if (!status) {
status = usb_new_device(udev);
if (status) {
mutex_lock(&usb_port_peer_mutex);
spin_lock_irq(&device_state_lock);
port_dev->child = NULL;
spin_unlock_irq(&device_state_lock);
mutex_unlock(&usb_port_peer_mutex);
} else {
if (hcd->usb_phy && !hdev->parent)
usb_phy_notify_connect(hcd->usb_phy,
udev->speed);
}
}
if (status)
goto loop_disable;
status = hub_power_remaining(hub);
if (status)
dev_dbg(hub->intfdev, "%dmA power budget left\n", status);
return;
loop_disable:
hub_port_disable(hub, port1, 1);
loop:
usb_ep0_reinit(udev);
release_devnum(udev);
hub_free_dev(udev);
if (retry_locked) {
mutex_unlock(hcd->address0_mutex);
usb_unlock_port(port_dev);
}
usb_put_dev(udev);
if ((status == -ENOTCONN) || (status == -ENOTSUPP))
break;
/* When halfway through our retry count, power-cycle the port */
if (i == (PORT_INIT_TRIES - 1) / 2) {
dev_info(&port_dev->dev, "attempt power cycle\n");
usb_hub_set_port_power(hdev, hub, port1, false);
msleep(2 * hub_power_on_good_delay(hub));
usb_hub_set_port_power(hdev, hub, port1, true);
msleep(hub_power_on_good_delay(hub));
}
}
if (hub->hdev->parent ||
!hcd->driver->port_handed_over ||
!(hcd->driver->port_handed_over)(hcd, port1)) {
if (status != -ENOTCONN && status != -ENODEV)
dev_err(&port_dev->dev,
"unable to enumerate USB device\n");
}
done:
hub_port_disable(hub, port1, 1);
if (hcd->driver->relinquish_port && !hub->hdev->parent) {
if (status != -ENOTCONN && status != -ENODEV)
hcd->driver->relinquish_port(hcd, port1);
}
}