usbcore: fix up device and power state tests
This patch (as734) rationalizes the various tests of device state and
power states. There are duplications and mistaken tests in several
places.
Perhaps the most interesting challenge is where the hub driver tests to
see that all the child devices are suspended before allowing itself to
be suspended. When CONFIG_USB_SUSPEND is set the test is
straightforward, since we expect that the children _will_ be suspended.
But when CONFIG_USB_SUSPEND isn't set, it's not so clear what should be
done. The code compromises by checking the child's
power.power_state.event field.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 92ecc4e..affbfb5 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -757,11 +757,13 @@
struct usb_device_driver *udriver;
int status = 0;
+ if (udev->state == USB_STATE_NOTATTACHED ||
+ udev->state == USB_STATE_SUSPENDED)
+ goto done;
+
if (udev->dev.driver == NULL)
goto done;
udriver = to_usb_device_driver(udev->dev.driver);
- if (udev->dev.power.power_state.event == msg.event)
- goto done;
status = udriver->suspend(udev, msg);
done:
@@ -776,14 +778,13 @@
struct usb_device_driver *udriver;
int status = 0;
- if (udev->dev.power.power_state.event == PM_EVENT_ON)
+ if (udev->state == USB_STATE_NOTATTACHED ||
+ udev->state != USB_STATE_SUSPENDED)
goto done;
if (udev->dev.driver == NULL)
goto done;
udriver = to_usb_device_driver(udev->dev.driver);
- if (udev->state == USB_STATE_NOTATTACHED)
- goto done;
status = udriver->resume(udev);
done:
@@ -798,15 +799,15 @@
struct usb_driver *driver;
int status = 0;
+ /* with no hardware, USB interfaces only use FREEZE and ON states */
+ if (interface_to_usbdev(intf)->state == USB_STATE_NOTATTACHED ||
+ !is_active(intf))
+ goto done;
+
if (intf->dev.driver == NULL)
goto done;
-
driver = to_usb_driver(intf->dev.driver);
- /* with no hardware, USB interfaces only use FREEZE and ON states */
- if (!is_active(intf))
- goto done;
-
if (driver->suspend && driver->resume) {
status = driver->suspend(intf, msg);
if (status)
@@ -831,25 +832,16 @@
static int resume_interface(struct usb_interface *intf)
{
struct usb_driver *driver;
- struct usb_device *udev;
int status = 0;
- if (intf->dev.power.power_state.event == PM_EVENT_ON)
+ if (interface_to_usbdev(intf)->state == USB_STATE_NOTATTACHED ||
+ is_active(intf))
goto done;
if (intf->dev.driver == NULL)
goto done;
-
driver = to_usb_driver(intf->dev.driver);
- udev = interface_to_usbdev(intf);
- if (udev->state == USB_STATE_NOTATTACHED)
- goto done;
-
- /* if driver was suspended, it has a resume method;
- * however, sysfs can wrongly mark things as suspended
- * (on the "no suspend method" FIXME path above)
- */
if (driver->resume) {
status = driver->resume(intf);
if (status)
@@ -904,6 +896,12 @@
int i;
struct usb_interface *intf;
+ /* Can't resume if the parent is suspended */
+ if (udev->parent && udev->parent->state == USB_STATE_SUSPENDED) {
+ dev_warn(&udev->dev, "can't resume; parent is suspended\n");
+ return -EHOSTUNREACH;
+ }
+
status = resume_device(udev);
if (status == 0 && udev->actconfig) {
for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c
index b6dacd7..5358e65 100644
--- a/drivers/usb/core/generic.c
+++ b/drivers/usb/core/generic.c
@@ -195,9 +195,6 @@
static int generic_resume(struct usb_device *udev)
{
- if (udev->state == USB_STATE_NOTATTACHED)
- return 0;
-
return usb_port_resume(udev);
}
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 7af53db..a310c7c 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1556,26 +1556,6 @@
if (port1 < 0)
return port1;
- if (udev->state == USB_STATE_SUSPENDED
- || udev->state == USB_STATE_NOTATTACHED) {
- return 0;
- }
-
- /* all interfaces must already be suspended */
- if (udev->actconfig) {
- int i;
-
- for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
- struct usb_interface *intf;
-
- intf = udev->actconfig->interface[i];
- if (is_active(intf)) {
- dev_dbg(&intf->dev, "nyet suspended\n");
- return -EBUSY;
- }
- }
- }
-
/* we change the device's upstream USB link,
* but root hubs have no upstream USB link.
*/
@@ -1614,8 +1594,6 @@
int usb_port_suspend(struct usb_device *udev)
{
#ifdef CONFIG_USB_SUSPEND
- if (udev->state == USB_STATE_NOTATTACHED)
- return -ENODEV;
return __usb_port_suspend(udev, udev->portnum);
#else
return 0;
@@ -1761,24 +1739,17 @@
*/
int usb_port_resume(struct usb_device *udev)
{
- int status;
-
- if (udev->state == USB_STATE_NOTATTACHED)
- return -ENODEV;
+ int status = 0;
/* we change the device's upstream USB link,
* but root hubs have no upstream USB link.
*/
if (udev->parent) {
#ifdef CONFIG_USB_SUSPEND
- if (udev->state == USB_STATE_SUSPENDED) {
- // NOTE swsusp may bork us, device state being wrong...
- // NOTE this fails if parent is also suspended...
- status = hub_port_resume(hdev_to_hub(udev->parent),
- udev->portnum, udev);
- } else
+ // NOTE this fails if parent is also suspended...
+ status = hub_port_resume(hdev_to_hub(udev->parent),
+ udev->portnum, udev);
#endif
- status = 0;
} else
status = finish_port_resume(udev);
if (status < 0)
@@ -1821,12 +1792,14 @@
struct usb_device *udev;
udev = hdev->children [port1-1];
- if (udev && (udev->dev.power.power_state.event
- == PM_EVENT_ON
+ if (udev && msg.event == PM_EVENT_SUSPEND &&
#ifdef CONFIG_USB_SUSPEND
- || udev->state != USB_STATE_SUSPENDED
+ udev->state != USB_STATE_SUSPENDED
+#else
+ udev->dev.power.power_state.event
+ == PM_EVENT_ON
#endif
- )) {
+ ) {
dev_dbg(&intf->dev, "port %d nyet suspended\n", port1);
return -EBUSY;
}