USB: simplify hub_restart() logic
This patch (as1081) straightens out the logic of the hub_restart()
routine. Each port of the hub is scanned and the driver makes sure
that ports which are supposed to be disabled really _are_ disabled.
Any ports with a significant change in status are flagged in
hub->change_bits, so that khubd can focus on them without the need to
scan all the ports a second time -- which means the hub->activating
flag is no longer needed.
Also, it is now recognized explicitly that the only reason for
resuming a port which was not suspended is to carry out a reset-resume
operation, which happens only in a non-CONFIG_USB_SUSPEND setting.
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 d0b37d7..bf1585b 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -805,8 +805,6 @@
if (udev->state == USB_STATE_NOTATTACHED)
goto done;
- if (udev->state != USB_STATE_SUSPENDED && !udev->reset_resume)
- goto done;
/* Can't resume it if it doesn't have a driver. */
if (udev->dev.driver == NULL) {
@@ -1173,11 +1171,8 @@
* then we're stuck. */
status = usb_resume_device(udev);
}
- } else {
-
- /* Needed for reset-resume */
+ } else if (udev->reset_resume)
status = usb_resume_device(udev);
- }
if (status == 0 && udev->actconfig) {
for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 976da1c..054a76d 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -72,7 +72,6 @@
unsigned limited_power:1;
unsigned quiescing:1;
- unsigned activating:1;
unsigned disconnected:1;
unsigned has_indicators:1;
@@ -539,7 +538,6 @@
{
/* (nonblocking) khubd and related activity won't re-trigger */
hub->quiescing = 1;
- hub->activating = 0;
/* (blocking) stop khubd and related activity */
usb_kill_urb(hub->urb);
@@ -554,7 +552,6 @@
int status;
hub->quiescing = 0;
- hub->activating = 1;
status = usb_submit_urb(hub->urb, GFP_NOIO);
if (status < 0)
@@ -638,81 +635,83 @@
hub_quiesce(hub);
}
-#define HUB_RESET 1
-#define HUB_RESUME 2
-#define HUB_RESET_RESUME 3
+enum hub_activation_type {
+ HUB_INIT, HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME
+};
-#ifdef CONFIG_PM
-
-static void hub_restart(struct usb_hub *hub, int type)
+static void hub_restart(struct usb_hub *hub, enum hub_activation_type type)
{
struct usb_device *hdev = hub->hdev;
int port1;
- /* Check each of the children to see if they require
- * USB-PERSIST handling or disconnection. Also check
- * each unoccupied port to make sure it is still disabled.
+ /* Check each port and set hub->change_bits to let khubd know
+ * which ports need attention.
*/
for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
struct usb_device *udev = hdev->children[port1-1];
- int status = 0;
+ int status;
u16 portstatus, portchange;
- if (!udev || udev->state == USB_STATE_NOTATTACHED) {
- if (type != HUB_RESET) {
- status = hub_port_status(hub, port1,
- &portstatus, &portchange);
- if (status == 0 && (portstatus &
- USB_PORT_STAT_ENABLE))
- clear_port_feature(hdev, port1,
- USB_PORT_FEAT_ENABLE);
- }
- continue;
- }
+ portstatus = portchange = 0;
+ status = hub_port_status(hub, port1, &portstatus, &portchange);
+ if (udev || (portstatus & USB_PORT_STAT_CONNECTION))
+ dev_dbg(hub->intfdev,
+ "port %d: status %04x change %04x\n",
+ port1, portstatus, portchange);
- /* Was the power session lost while we were suspended? */
- switch (type) {
- case HUB_RESET_RESUME:
- portstatus = 0;
- portchange = USB_PORT_STAT_C_CONNECTION;
- break;
-
- case HUB_RESET:
- case HUB_RESUME:
- status = hub_port_status(hub, port1,
- &portstatus, &portchange);
- break;
- }
-
- /* For "USB_PERSIST"-enabled children we must
- * mark the child device for reset-resume and
- * turn off the various status changes to prevent
- * khubd from disconnecting it later.
+ /* After anything other than HUB_RESUME (i.e., initialization
+ * or any sort of reset), every port should be disabled.
+ * Unconnected ports should likewise be disabled (paranoia),
+ * and so should ports for which we have no usb_device.
*/
- if (udev->persist_enabled && status == 0 &&
- !(portstatus & USB_PORT_STAT_ENABLE)) {
+ if ((portstatus & USB_PORT_STAT_ENABLE) && (
+ type != HUB_RESUME ||
+ !(portstatus & USB_PORT_STAT_CONNECTION) ||
+ !udev ||
+ udev->state == USB_STATE_NOTATTACHED)) {
+ clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE);
+ portstatus &= ~USB_PORT_STAT_ENABLE;
+ }
+
+ if (!udev || udev->state == USB_STATE_NOTATTACHED) {
+ /* Tell khubd to disconnect the device or
+ * check for a new connection
+ */
+ if (udev || (portstatus & USB_PORT_STAT_CONNECTION))
+ set_bit(port1, hub->change_bits);
+
+ } else if (portstatus & USB_PORT_STAT_ENABLE) {
+ /* The power session apparently survived the resume.
+ * If there was an overcurrent or suspend change
+ * (i.e., remote wakeup request), have khubd
+ * take care of it.
+ */
+ if (portchange)
+ set_bit(port1, hub->change_bits);
+
+ } else if (udev->persist_enabled) {
+ /* Turn off the status changes to prevent khubd
+ * from disconnecting the device.
+ */
if (portchange & USB_PORT_STAT_C_ENABLE)
clear_port_feature(hub->hdev, port1,
USB_PORT_FEAT_C_ENABLE);
if (portchange & USB_PORT_STAT_C_CONNECTION)
clear_port_feature(hub->hdev, port1,
USB_PORT_FEAT_C_CONNECTION);
+#ifdef CONFIG_PM
udev->reset_resume = 1;
+#endif
+ } else {
+ /* The power session is gone; tell khubd */
+ usb_set_device_state(udev, USB_STATE_NOTATTACHED);
+ set_bit(port1, hub->change_bits);
}
-
- /* Otherwise for a reset_resume we must disconnect the child,
- * but as we may not lock the child device here
- * we have to do a "logical" disconnect.
- */
- else if (type == HUB_RESET_RESUME)
- hub_port_logical_disconnect(hub, port1);
}
hub_activate(hub);
}
-#endif /* CONFIG_PM */
-
/* caller has locked the hub device */
static int hub_pre_reset(struct usb_interface *intf)
{
@@ -728,7 +727,7 @@
struct usb_hub *hub = usb_get_intfdata(intf);
hub_power_on(hub);
- hub_activate(hub);
+ hub_restart(hub, HUB_POST_RESET);
return 0;
}
@@ -2903,7 +2902,7 @@
continue;
connect_change = test_bit(i, hub->change_bits);
if (!test_and_clear_bit(i, hub->event_bits) &&
- !connect_change && !hub->activating)
+ !connect_change)
continue;
ret = hub_port_status(hub, i,
@@ -2911,11 +2910,6 @@
if (ret < 0)
continue;
- if (hub->activating && !hdev->children[i-1] &&
- (portstatus &
- USB_PORT_STAT_CONNECTION))
- connect_change = 1;
-
if (portchange & USB_PORT_STAT_C_CONNECTION) {
clear_port_feature(hdev, i,
USB_PORT_FEAT_C_CONNECTION);
@@ -3011,8 +3005,6 @@
}
}
- hub->activating = 0;
-
/* If this is a root hub, tell the HCD it's okay to
* re-enable port-change interrupts now. */
if (!hdev->parent && !hub->busy_bits[0])