diff options
| -rw-r--r-- | drivers/usb/core/hub.c | 91 |
1 files changed, 81 insertions, 10 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index d99963873e37..b97110ca352d 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); } } |