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path: root/drivers/usb/core
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Diffstat (limited to 'drivers/usb/core')
-rw-r--r--drivers/usb/core/hub.c91
1 files changed, 81 insertions, 10 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index d99963873e3..b97110ca352 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -77,6 +77,7 @@ struct usb_hub {
unsigned has_indicators:1;
u8 indicator[USB_MAXCHILDREN];
struct delayed_work leds;
+ struct delayed_work init_work;
};
@@ -515,10 +516,14 @@ void usb_hub_tt_clear_buffer (struct usb_device *udev, int pipe)
}
EXPORT_SYMBOL_GPL(usb_hub_tt_clear_buffer);
-static void hub_power_on(struct usb_hub *hub)
+/* If do_delay is false, return the number of milliseconds the caller
+ * needs to delay.
+ */
+static unsigned hub_power_on(struct usb_hub *hub, bool do_delay)
{
int port1;
unsigned pgood_delay = hub->descriptor->bPwrOn2PwrGood * 2;
+ unsigned delay;
u16 wHubCharacteristics =
le16_to_cpu(hub->descriptor->wHubCharacteristics);
@@ -537,7 +542,10 @@ static void hub_power_on(struct usb_hub *hub)
set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
/* Wait at least 100 msec for power to become stable */
- msleep(max(pgood_delay, (unsigned) 100));
+ delay = max(pgood_delay, (unsigned) 100);
+ if (do_delay)
+ msleep(delay);
+ return delay;
}
static int hub_hub_status(struct usb_hub *hub,
@@ -599,21 +607,55 @@ static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
}
enum hub_activation_type {
- HUB_INIT, HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME
+ HUB_INIT, HUB_INIT2, HUB_INIT3,
+ HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME,
};
+static void hub_init_func2(struct work_struct *ws);
+static void hub_init_func3(struct work_struct *ws);
+
static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
{
struct usb_device *hdev = hub->hdev;
int port1;
int status;
bool need_debounce_delay = false;
+ unsigned delay;
+
+ /* Continue a partial initialization */
+ if (type == HUB_INIT2)
+ goto init2;
+ if (type == HUB_INIT3)
+ goto init3;
/* After a resume, port power should still be on.
* For any other type of activation, turn it on.
*/
- if (type != HUB_RESUME)
- hub_power_on(hub);
+ if (type != HUB_RESUME) {
+
+ /* Speed up system boot by using a delayed_work for the
+ * hub's initial power-up delays. This is pretty awkward
+ * and the implementation looks like a home-brewed sort of
+ * setjmp/longjmp, but it saves at least 100 ms for each
+ * root hub (assuming usbcore is compiled into the kernel
+ * rather than as a module). It adds up.
+ *
+ * This can't be done for HUB_RESUME or HUB_RESET_RESUME
+ * because for those activation types the ports have to be
+ * operational when we return. In theory this could be done
+ * for HUB_POST_RESET, but it's easier not to.
+ */
+ if (type == HUB_INIT) {
+ delay = hub_power_on(hub, false);
+ PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func2);
+ schedule_delayed_work(&hub->init_work,
+ msecs_to_jiffies(delay));
+ return; /* Continues at init2: below */
+ } else {
+ hub_power_on(hub, true);
+ }
+ }
+ init2:
/* Check each port and set hub->change_bits to let khubd know
* which ports need attention.
@@ -692,9 +734,20 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
* If any port-status changes do occur during this delay, khubd
* will see them later and handle them normally.
*/
- if (need_debounce_delay)
- msleep(HUB_DEBOUNCE_STABLE);
-
+ if (need_debounce_delay) {
+ delay = HUB_DEBOUNCE_STABLE;
+
+ /* Don't do a long sleep inside a workqueue routine */
+ if (type == HUB_INIT2) {
+ PREPARE_DELAYED_WORK(&hub->init_work, hub_init_func3);
+ schedule_delayed_work(&hub->init_work,
+ msecs_to_jiffies(delay));
+ return; /* Continues at init3: below */
+ } else {
+ msleep(delay);
+ }
+ }
+ init3:
hub->quiescing = 0;
status = usb_submit_urb(hub->urb, GFP_NOIO);
@@ -707,6 +760,21 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
kick_khubd(hub);
}
+/* Implement the continuations for the delays above */
+static void hub_init_func2(struct work_struct *ws)
+{
+ struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);
+
+ hub_activate(hub, HUB_INIT2);
+}
+
+static void hub_init_func3(struct work_struct *ws)
+{
+ struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);
+
+ hub_activate(hub, HUB_INIT3);
+}
+
enum hub_quiescing_type {
HUB_DISCONNECT, HUB_PRE_RESET, HUB_SUSPEND
};
@@ -716,6 +784,8 @@ static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type)
struct usb_device *hdev = hub->hdev;
int i;
+ cancel_delayed_work_sync(&hub->init_work);
+
/* khubd and related activity won't re-trigger */
hub->quiescing = 1;
@@ -1099,6 +1169,7 @@ descriptor_error:
hub->intfdev = &intf->dev;
hub->hdev = hdev;
INIT_DELAYED_WORK(&hub->leds, led_work);
+ INIT_DELAYED_WORK(&hub->init_work, NULL);
usb_get_intf(intf);
usb_set_intfdata (intf, hub);
@@ -3035,7 +3106,7 @@ static void hub_events(void)
i);
clear_port_feature(hdev, i,
USB_PORT_FEAT_C_OVER_CURRENT);
- hub_power_on(hub);
+ hub_power_on(hub, true);
}
if (portchange & USB_PORT_STAT_C_RESET) {
@@ -3070,7 +3141,7 @@ static void hub_events(void)
dev_dbg (hub_dev, "overcurrent change\n");
msleep(500); /* Cool down */
clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
- hub_power_on(hub);
+ hub_power_on(hub, true);
}
}