USB: add new routine for checking port-resume type
This patch (as1070) creates a new subroutine to check whether a device
can be resumed. This code is needed even when CONFIG_USB_SUSPEND
isn't set, because devices do suspend themselves when the root hub
(and hence the entire bus) is suspended, and power sessions can get
lost during a system sleep even without individual port suspends.
The patch also fixes a loose end in USB-Persist reset-resume handling.
When a low- or full-speed device is attached to an EHCI's companion
controller, the port handoff during resume will cause the companion
port's connect-status-change feature to be set. If that flag isn't
cleared, the port-reset code will think it indicates that the device
has been unplugged and the reset-resume will fail.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 2a5c283..d14da21 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1821,6 +1821,45 @@
#ifdef CONFIG_PM
+#define MASK_BITS (USB_PORT_STAT_POWER | USB_PORT_STAT_CONNECTION | \
+ USB_PORT_STAT_SUSPEND)
+#define WANT_BITS (USB_PORT_STAT_POWER | USB_PORT_STAT_CONNECTION)
+
+/* Determine whether the device on a port is ready for a normal resume,
+ * is ready for a reset-resume, or should be disconnected.
+ */
+static int check_port_resume_type(struct usb_device *udev,
+ struct usb_hub *hub, int port1,
+ int status, unsigned portchange, unsigned portstatus)
+{
+ /* Is the device still present? */
+ if (status || (portstatus & MASK_BITS) != WANT_BITS) {
+ if (status >= 0)
+ status = -ENODEV;
+ }
+
+ /* Can't do a normal resume if the port isn't enabled */
+ else if (!(portstatus & USB_PORT_STAT_ENABLE) && !udev->reset_resume)
+ status = -ENODEV;
+
+ if (status) {
+ dev_dbg(hub->intfdev,
+ "port %d status %04x.%04x after resume, %d\n",
+ port1, portchange, portstatus, status);
+ } else if (udev->reset_resume) {
+
+ /* Late port handoff can set status-change bits */
+ if (portchange & USB_PORT_STAT_C_CONNECTION)
+ clear_port_feature(hub->hdev, port1,
+ USB_PORT_FEAT_C_CONNECTION);
+ if (portchange & USB_PORT_STAT_C_ENABLE)
+ clear_port_feature(hub->hdev, port1,
+ USB_PORT_FEAT_C_ENABLE);
+ }
+
+ return status;
+}
+
#ifdef CONFIG_USB_SUSPEND
/*
@@ -2025,7 +2064,6 @@
int port1 = udev->portnum;
int status;
u16 portchange, portstatus;
- unsigned mask_flags, want_flags;
/* Skip the initial Clear-Suspend step for a remote wakeup */
status = hub_port_status(hub, port1, &portstatus, &portchange);
@@ -2054,35 +2092,23 @@
*/
status = hub_port_status(hub, port1, &portstatus, &portchange);
- SuspendCleared:
- if (udev->reset_resume)
- want_flags = USB_PORT_STAT_POWER
- | USB_PORT_STAT_CONNECTION;
- else
- want_flags = USB_PORT_STAT_POWER
- | USB_PORT_STAT_CONNECTION
- | USB_PORT_STAT_ENABLE;
- mask_flags = want_flags | USB_PORT_STAT_SUSPEND;
+ /* TRSMRCY = 10 msec */
+ msleep(10);
+ }
- if (status < 0 || (portstatus & mask_flags) != want_flags) {
- dev_dbg(hub->intfdev,
- "port %d status %04x.%04x after resume, %d\n",
- port1, portchange, portstatus, status);
- if (status >= 0)
- status = -ENODEV;
- } else {
- if (portchange & USB_PORT_STAT_C_SUSPEND)
- clear_port_feature(hub->hdev, port1,
- USB_PORT_FEAT_C_SUSPEND);
- /* TRSMRCY = 10 msec */
- msleep(10);
- }
+ SuspendCleared:
+ if (status == 0) {
+ if (portchange & USB_PORT_STAT_C_SUSPEND)
+ clear_port_feature(hub->hdev, port1,
+ USB_PORT_FEAT_C_SUSPEND);
}
clear_bit(port1, hub->busy_bits);
if (!hub->hdev->parent && !hub->busy_bits[0])
usb_enable_root_hub_irq(hub->hdev->bus);
+ status = check_port_resume_type(udev,
+ hub, port1, status, portchange, portstatus);
if (status == 0)
status = finish_port_resume(udev);
if (status < 0) {
@@ -2115,12 +2141,23 @@
return 0;
}
+/* However we may need to do a reset-resume */
+
int usb_port_resume(struct usb_device *udev)
{
- int status = 0;
+ struct usb_hub *hub = hdev_to_hub(udev->parent);
+ int port1 = udev->portnum;
+ int status;
+ u16 portchange, portstatus;
- /* However we may need to do a reset-resume */
- if (udev->reset_resume) {
+ status = hub_port_status(hub, port1, &portstatus, &portchange);
+ status = check_port_resume_type(udev,
+ hub, port1, status, portchange, portstatus);
+
+ if (status) {
+ dev_dbg(&udev->dev, "can't resume, status %d\n", status);
+ hub_port_logical_disconnect(hub, port1);
+ } else if (udev->reset_resume) {
dev_dbg(&udev->dev, "reset-resume\n");
status = usb_reset_device(udev);
}