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authorAlan Stern <stern@rowland.harvard.edu>2008-03-03 15:15:51 -0500
committerGreg Kroah-Hartman <gregkh@suse.de>2008-04-24 21:16:32 -0700
commit5e6effaed6da94e727cd45f945ad2489af8570b3 (patch)
tree2995db2a93c931f3e4a7e4e3203870d5d7f93eb6 /drivers/usb/core
parent3eb14915a300f539f271e3716f2421bb0697ed48 (diff)
USB: make USB-PERSIST work after every system sleep
This patch (as1046) makes USB-PERSIST work more in accordance with the documentation. Currently it takes effect only in cases where the root hub has lost power or been reset, but it is supposed to operate whenever a power session was dropped during a system sleep. A new hub_restart() routine carries out the duties required during a reset or a reset-resume. It checks to see whether occupied ports are still enabled, and if they aren't then it clears the enable-change and connect-change features (to prevent interference by khubd) and sets the child device's reset_resume flag. It also checks ports that are supposed to be unoccupied to verify that the firmware hasn't left the port in an enabled state. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/core')
-rw-r--r--drivers/usb/core/hub.c114
1 files changed, 80 insertions, 34 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 087e3bb70e0..df68e256258 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -644,6 +644,81 @@ static void hub_stop(struct usb_hub *hub)
hub_quiesce(hub);
}
+#define HUB_RESET 1
+#define HUB_RESUME 2
+#define HUB_RESET_RESUME 3
+
+#ifdef CONFIG_PM
+
+static void hub_restart(struct usb_hub *hub, int 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.
+ */
+ for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
+ struct usb_device *udev = hdev->children[port1-1];
+ int status = 0;
+ 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;
+ }
+
+ /* 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.
+ */
+ if (USB_PERSIST && udev->persist_enabled && status == 0 &&
+ !(portstatus & USB_PORT_STAT_ENABLE)) {
+ 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);
+ udev->reset_resume = 1;
+ }
+
+ /* 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)
{
@@ -2015,49 +2090,20 @@ static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
static int hub_resume(struct usb_interface *intf)
{
- struct usb_hub *hub = usb_get_intfdata (intf);
-
- dev_dbg(&intf->dev, "%s\n", __FUNCTION__);
+ struct usb_hub *hub = usb_get_intfdata(intf);
- /* tell khubd to look for changes on this hub */
- hub_activate(hub);
+ dev_dbg(&intf->dev, "%s\n", __func__);
+ hub_restart(hub, HUB_RESUME);
return 0;
}
static int hub_reset_resume(struct usb_interface *intf)
{
struct usb_hub *hub = usb_get_intfdata(intf);
- struct usb_device *hdev = hub->hdev;
- int port1;
+ dev_dbg(&intf->dev, "%s\n", __func__);
hub_power_on(hub);
-
- for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
- struct usb_device *child = hdev->children[port1-1];
-
- if (child) {
-
- /* For "USB_PERSIST"-enabled children we must
- * mark the child device for reset-resume and
- * turn off the connect-change status to prevent
- * khubd from disconnecting it later.
- */
- if (USB_PERSIST && child->persist_enabled) {
- child->reset_resume = 1;
- clear_port_feature(hdev, port1,
- USB_PORT_FEAT_C_CONNECTION);
-
- /* Otherwise we must disconnect the child,
- * but as we may not lock the child device here
- * we have to do a "logical" disconnect.
- */
- } else {
- hub_port_logical_disconnect(hub, port1);
- }
- }
- }
-
- hub_activate(hub);
+ hub_restart(hub, HUB_RESET_RESUME);
return 0;
}