usb: hub: rename khubd to hub_wq in documentation and comments

USB hub has started to use a workqueue instead of kthread. Let's update
the documentation and comments here and there.

This patch mostly just replaces "khubd" with "hub_wq". There are only few
exceptions where the whole sentence was updated. These more complicated
changes can be found in the following files:

	   Documentation/usb/hotplug.txt
	   drivers/net/usb/usbnet.c
	   drivers/usb/core/hcd.c
	   drivers/usb/host/ohci-hcd.c
	   drivers/usb/host/xhci.c

Signed-off-by: Petr Mladek <pmladek@suse.cz>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/DocBook/usb.tmpl

@@ -593,7 +593,7 @@ for (;;) {
 	    Each device has one control endpoint (endpoint zero)
 	    which supports a limited RPC style RPC access.
 	    Devices are configured
-	    by khubd (in the kernel) setting a device-wide
+	    by hub_wq (in the kernel) setting a device-wide
 	    <emphasis>configuration</emphasis> that affects things
 	    like power consumption and basic functionality.
 	    The endpoints are part of USB <emphasis>interfaces</emphasis>,

Documentation/usb/WUSB-Design-overview.txt

@@ -308,7 +308,7 @@ HC picks the /DN_Connect/ out (nep module sends to notif.c for delivery
 into /devconnect/). This process starts the authentication process for
 the device. First we allocate a /fake port/ and assign an
 unauthenticated address (128 to 255--what we really do is
-0x80 | fake_port_idx). We fiddle with the fake port status and /khubd/
+0x80 | fake_port_idx). We fiddle with the fake port status and /hub_wq/
 sees a new connection, so he moves on to enable the fake port with a reset.
 
 So now we are in the reset path -- we know we have a non-yet enumerated
@@ -317,7 +317,7 @@ device with an unauthorized address; we ask user space to authenticate
 exchange (FIXME: not yet done) and issue a /set address 0/ to bring the
 device to the default state. Device is authenticated.
 
-From here, the USB stack takes control through the usb_hcd ops. khubd
+From here, the USB stack takes control through the usb_hcd ops. hub_wq
 has seen the port status changes, as we have been toggling them. It will
 start enumerating and doing transfers through usb_hcd->urb_enqueue() to
 read descriptors and move our data.
@@ -331,7 +331,7 @@ Keep Alive IE; it responds with a /DN_Alive/ pong during the DNTS (this
 arrives to us as a notification through
 devconnect.c:wusb_handle_dn_alive(). If a device times out, we
 disconnect it from the system (cleaning up internal information and
-toggling the bits in the fake hub port, which kicks khubd into removing
+toggling the bits in the fake hub port, which kicks hub_wq into removing
 the rest of the stuff).
 
 This is done through devconnect:__wusb_check_devs(), which will scan the

Documentation/usb/hotplug.txt

@@ -58,7 +58,7 @@ USB POLICY AGENT
 
 The USB subsystem currently invokes /sbin/hotplug when USB devices
 are added or removed from system.  The invocation is done by the kernel
-hub daemon thread [khubd], or else as part of root hub initialization
+hub workqueue [hub_wq], or else as part of root hub initialization
 (done by init, modprobe, kapmd, etc).  Its single command line parameter
 is the string "usb", and it passes these environment variables:
 

drivers/net/usb/usbnet.c

@@ -69,8 +69,9 @@
 // reawaken network queue this soon after stopping; else watchdog barks
 #define TX_TIMEOUT_JIFFIES	(5*HZ)
 
-// throttle rx/tx briefly after some faults, so khubd might disconnect()
-// us (it polls at HZ/4 usually) before we report too many false errors.
+/* throttle rx/tx briefly after some faults, so hub_wq might disconnect()
+ * us (it polls at HZ/4 usually) before we report too many false errors.
+ */
 #define THROTTLE_JIFFIES	(HZ/8)
 
 // between wakeups
@@ -595,9 +596,9 @@ static void rx_complete (struct urb *urb)
 			  "rx shutdown, code %d\n", urb_status);
 		goto block;
 
-	/* we get controller i/o faults during khubd disconnect() delays.
+	/* we get controller i/o faults during hub_wq disconnect() delays.
 	 * throttle down resubmits, to avoid log floods; just temporarily,
-	 * so we still recover when the fault isn't a khubd delay.
+	 * so we still recover when the fault isn't a hub_wq delay.
 	 */
 	case -EPROTO:
 	case -ETIME:
@@ -1185,8 +1186,9 @@ static void tx_complete (struct urb *urb)
 		case -ESHUTDOWN:		// hardware gone
 			break;
 
-		// like rx, tx gets controller i/o faults during khubd delays
-		// and so it uses the same throttling mechanism.
+		/* like rx, tx gets controller i/o faults during hub_wq
+		 * delays and so it uses the same throttling mechanism.
+		 */
 		case -EPROTO:
 		case -ETIME:
 		case -EILSEQ:

drivers/usb/README

@@ -24,7 +24,7 @@ Here is a list of what each subdirectory here is, and what is contained in
 them.
 
 core/		- This is for the core USB host code, including the
-		  usbfs files and the hub class driver ("khubd").
+		  usbfs files and the hub class driver ("hub_wq").
 
 host/		- This is for USB host controller drivers.  This
 		  includes UHCI, OHCI, EHCI, and others that might

drivers/usb/core/hcd.c

@@ -2301,7 +2301,7 @@ EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub);
  * Context: in_interrupt()
  *
  * Starts enumeration, with an immediate reset followed later by
- * khubd identifying and possibly configuring the device.
+ * hub_wq identifying and possibly configuring the device.
  * This is needed by OTG controller drivers, where it helps meet
  * HNP protocol timing requirements for starting a port reset.
  *
@@ -2320,7 +2320,7 @@ int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num)
 	if (port_num && hcd->driver->start_port_reset)
 		status = hcd->driver->start_port_reset(hcd, port_num);
 
-	/* run khubd shortly after (first) root port reset finishes;
+	/* allocate hub_wq shortly after (first) root port reset finishes;
 	 * it may issue others, until at least 50 msecs have passed.
 	 */
 	if (status == 0)
@@ -2383,7 +2383,7 @@ void usb_hc_died (struct usb_hcd *hcd)
 	if (hcd->rh_registered) {
 		clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
 
-		/* make khubd clean up old urbs and devices */
+		/* make hub_wq clean up old urbs and devices */
 		usb_set_device_state (hcd->self.root_hub,
 				USB_STATE_NOTATTACHED);
 		usb_kick_hub_wq(hcd->self.root_hub);
@@ -2393,7 +2393,7 @@ void usb_hc_died (struct usb_hcd *hcd)
 		if (hcd->rh_registered) {
 			clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
 
-			/* make khubd clean up old urbs and devices */
+			/* make hub_wq clean up old urbs and devices */
 			usb_set_device_state(hcd->self.root_hub,
 					USB_STATE_NOTATTACHED);
 			usb_kick_hub_wq(hcd->self.root_hub);
@@ -2655,7 +2655,7 @@ int usb_add_hcd(struct usb_hcd *hcd,
 	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
 
 	/* HC is in reset state, but accessible.  Now do the one-time init,
-	 * bottom up so that hcds can customize the root hubs before khubd
+	 * bottom up so that hcds can customize the root hubs before hub_wq
 	 * starts talking to them.  (Note, bus id is assigned early too.)
 	 */
 	if ((retval = hcd_buffer_create(hcd)) != 0) {

drivers/usb/core/hub.c

@@ -652,7 +652,7 @@ static void hub_irq(struct urb *urb)
 		hub->error = status;
 		/* FALL THROUGH */
 
-	/* let khubd handle things */
+	/* let hub_wq handle things */
 	case 0:			/* we got data:  port status changed */
 		bits = 0;
 		for (i = 0; i < urb->actual_length; ++i)
@@ -664,7 +664,7 @@ static void hub_irq(struct urb *urb)
 
 	hub->nerrors = 0;
 
-	/* Something happened, let khubd figure it out */
+	/* Something happened, let hub_wq figure it out */
 	kick_hub_wq(hub);
 
 resubmit:
@@ -695,7 +695,7 @@ hub_clear_tt_buffer (struct usb_device *hdev, u16 devinfo, u16 tt)
 }
 
 /*
- * enumeration blocks khubd for a long time. we use keventd instead, since
+ * enumeration blocks hub_wq for a long time. we use keventd instead, since
  * long blocking there is the exception, not the rule.  accordingly, HCDs
  * talking to TTs must queue control transfers (not just bulk and iso), so
  * both can talk to the same hub concurrently.
@@ -961,7 +961,7 @@ static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
 
 /*
  * Disable a port and mark a logical connect-change event, so that some
- * time later khubd will disconnect() any existing usb_device on the port
+ * time later hub_wq will disconnect() any existing usb_device on the port
  * and will re-enumerate if there actually is a device attached.
  */
 static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
@@ -974,7 +974,7 @@ static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
 	 *  - SRP saves power that way
 	 *  - ... new call, TBD ...
 	 * That's easy if this hub can switch power per-port, and
-	 * khubd reactivates the port later (timer, SRP, etc).
+	 * hub_wq reactivates the port later (timer, SRP, etc).
 	 * Powerdown must be optional, because of reset/DFU.
 	 */
 
@@ -987,7 +987,7 @@ static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
  * @udev: device to be disabled and removed
  * Context: @udev locked, must be able to sleep.
  *
- * After @udev's port has been disabled, khubd is notified and it will
+ * After @udev's port has been disabled, hub_wq is notified and it will
  * see that the device has been disconnected.  When the device is
  * physically unplugged and something is plugged in, the events will
  * be received and processed normally.
@@ -1107,7 +1107,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
  init2:
 
 	/*
-	 * Check each port and set hub->change_bits to let khubd know
+	 * Check each port and set hub->change_bits to let hub_wq know
 	 * which ports need attention.
 	 */
 	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
@@ -1174,7 +1174,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 			clear_bit(port1, hub->removed_bits);
 
 		if (!udev || udev->state == USB_STATE_NOTATTACHED) {
-			/* Tell khubd to disconnect the device or
+			/* Tell hub_wq to disconnect the device or
 			 * check for a new connection
 			 */
 			if (udev || (portstatus & USB_PORT_STAT_CONNECTION) ||
@@ -1187,7 +1187,7 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 				USB_SS_PORT_LS_U0;
 			/* The power session apparently survived the resume.
 			 * If there was an overcurrent or suspend change
-			 * (i.e., remote wakeup request), have khubd
+			 * (i.e., remote wakeup request), have hub_wq
 			 * take care of it.  Look at the port link state
 			 * for USB 3.0 hubs, since they don't have a suspend
 			 * change bit, and they don't set the port link change
@@ -1208,18 +1208,18 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 				set_bit(port1, hub->change_bits);
 
 		} else {
-			/* The power session is gone; tell khubd */
+			/* The power session is gone; tell hub_wq */
 			usb_set_device_state(udev, USB_STATE_NOTATTACHED);
 			set_bit(port1, hub->change_bits);
 		}
 	}
 
 	/* If no port-status-change flags were set, we don't need any
 	 * debouncing.  If flags were set we can try to debounce the
-	 * ports all at once right now, instead of letting khubd do them
+	 * ports all at once right now, instead of letting hub_wq do them
 	 * one at a time later on.
 	 *
-	 * If any port-status changes do occur during this delay, khubd
+	 * If any port-status changes do occur during this delay, hub_wq
 	 * will see them later and handle them normally.
 	 */
 	if (need_debounce_delay) {
@@ -1280,7 +1280,7 @@ static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type)
 
 	cancel_delayed_work_sync(&hub->init_work);
 
-	/* khubd and related activity won't re-trigger */
+	/* hub_wq and related activity won't re-trigger */
 	hub->quiescing = 1;
 
 	if (type != HUB_SUSPEND) {
@@ -1291,7 +1291,7 @@ static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type)
 		}
 	}
 
-	/* Stop khubd and related activity */
+	/* Stop hub_wq and related activity */
 	usb_kill_urb(hub->urb);
 	if (hub->has_indicators)
 		cancel_delayed_work_sync(&hub->leds);
@@ -1613,7 +1613,7 @@ static int hub_configure(struct usb_hub *hub,
 	if (ret < 0)
 		goto fail;
 
-	/* Update the HCD's internal representation of this hub before khubd
+	/* Update the HCD's internal representation of this hub before hub_wq
 	 * starts getting port status changes for devices under the hub.
 	 */
 	if (hcd->driver->update_hub_device) {
@@ -2045,7 +2045,7 @@ static void choose_devnum(struct usb_device *udev)
 	int		devnum;
 	struct usb_bus	*bus = udev->bus;
 
-	/* If khubd ever becomes multithreaded, this will need a lock */
+	/* If hub_wq ever becomes multithreaded, this will need a lock */
 	if (udev->wusb) {
 		devnum = udev->portnum + 1;
 		BUG_ON(test_bit(devnum, bus->devmap.devicemap));
@@ -3074,7 +3074,7 @@ static unsigned wakeup_enabled_descendants(struct usb_device *udev)
  * Once VBUS drop breaks the circuit, the port it's using has to go through
  * normal re-enumeration procedures, starting with enabling VBUS power.
  * Other than re-initializing the hub (plug/unplug, except for root hubs),
- * Linux (2.6) currently has NO mechanisms to initiate that:  no khubd
+ * Linux (2.6) currently has NO mechanisms to initiate that:  no hub_wq
  * timer, no SRP, no requests through sysfs.
  *
  * If Runtime PM isn't enabled or used, non-SuperSpeed devices may not get
@@ -3216,7 +3216,7 @@ static int finish_port_resume(struct usb_device *udev)
 	/* usb ch9 identifies four variants of SUSPENDED, based on what
 	 * state the device resumes to.  Linux currently won't see the
 	 * first two on the host side; they'd be inside hub_port_init()
-	 * during many timeouts, but khubd can't suspend until later.
+	 * during many timeouts, but hub_wq can't suspend until later.
 	 */
 	usb_set_device_state(udev, udev->actconfig
 			? USB_STATE_CONFIGURED
@@ -3581,7 +3581,7 @@ static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
 
 	dev_dbg(&intf->dev, "%s\n", __func__);
 
-	/* stop khubd and related activity */
+	/* stop hub_wq and related activity */
 	hub_quiesce(hub, HUB_SUSPEND);
 	return 0;
 }
@@ -4977,10 +4977,10 @@ static void port_event(struct usb_hub *hub, int port1)
 	 * On disconnect USB3 protocol ports transit from U0 to
 	 * SS.Inactive to Rx.Detect. If this happens a warm-
 	 * reset is not needed, but a (re)connect may happen
-	 * before khubd runs and sees the disconnect, and the
+	 * before hub_wq runs and sees the disconnect, and the
 	 * device may be an unknown state.
 	 *
-	 * If the port went through SS.Inactive without khubd
+	 * If the port went through SS.Inactive without hub_wq
 	 * seeing it the C_LINK_STATE change flag will be set,
 	 * and we reset the dev to put it in a known state.
 	 */
@@ -5290,7 +5290,7 @@ static int descriptors_changed(struct usb_device *udev,
  * former operating configuration.  If the reset fails, or the device's
  * descriptors change from their values before the reset, or the original
  * configuration and altsettings cannot be restored, a flag will be set
- * telling khubd to pretend the device has been disconnected and then
+ * telling hub_wq to pretend the device has been disconnected and then
  * re-connected.  All drivers will be unbound, and the device will be
  * re-enumerated and probed all over again.
  *

drivers/usb/host/ehci-fsl.c

@@ -627,7 +627,7 @@ static int ehci_start_port_reset(struct usb_hcd *hcd, unsigned port)
 	if (!(status & PORT_CONNECT))
 		return -ENODEV;
 
-	/* khubd will finish the reset later */
+	/* hub_wq will finish the reset later */
 	if (ehci_is_TDI(ehci)) {
 		writel(PORT_RESET |
 		       (status & ~(PORT_CSC | PORT_PEC | PORT_OCC)),

drivers/usb/host/ehci-hcd.c

@@ -788,7 +788,7 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
 				continue;
 
 			/* start 20 msec resume signaling from this port,
-			 * and make khubd collect PORT_STAT_C_SUSPEND to
+			 * and make hub_wq collect PORT_STAT_C_SUSPEND to
 			 * stop that signaling.  Use 5 ms extra for safety,
 			 * like usb_port_resume() does.
 			 */

drivers/usb/host/ehci-hub.c

@@ -656,7 +656,7 @@ ehci_hub_status_data (struct usb_hcd *hcd, char *buf)
 
 		/*
 		 * Return status information even for ports with OWNER set.
-		 * Otherwise khubd wouldn't see the disconnect event when a
+		 * Otherwise hub_wq wouldn't see the disconnect event when a
 		 * high-speed device is switched over to the companion
 		 * controller by the user.
 		 */
@@ -902,7 +902,7 @@ int ehci_hub_control(
 
 		/*
 		 * Even if OWNER is set, so the port is owned by the
-		 * companion controller, khubd needs to be able to clear
+		 * companion controller, hub_wq needs to be able to clear
 		 * the port-change status bits (especially
 		 * USB_PORT_STAT_C_CONNECTION).
 		 */
@@ -1000,7 +1000,7 @@ int ehci_hub_control(
 			 * However, not all EHCI implementations do this
 			 * automatically, even if they _do_ support per-port
 			 * power switching; they're allowed to just limit the
-			 * current.  khubd will turn the power back on.
+			 * current.  hub_wq will turn the power back on.
 			 */
 			if (((temp & PORT_OC) || (ehci->need_oc_pp_cycle))
 					&& HCS_PPC(ehci->hcs_params)) {
@@ -1085,7 +1085,7 @@ int ehci_hub_control(
 		}
 
 		/*
-		 * Even if OWNER is set, there's no harm letting khubd
+		 * Even if OWNER is set, there's no harm letting hub_wq
 		 * see the wPortStatus values (they should all be 0 except
 		 * for PORT_POWER anyway).
 		 */

drivers/usb/host/fhci-hcd.c

@@ -360,12 +360,12 @@ static int fhci_start(struct usb_hcd *hcd)
 	hcd->state = HC_STATE_RUNNING;
 
 	/*
-	 * From here on, khubd concurrently accesses the root
+	 * From here on, hub_wq concurrently accesses the root
 	 * hub; drivers will be talking to enumerated devices.
-	 * (On restart paths, khubd already knows about the root
+	 * (On restart paths, hub_wq already knows about the root
 	 * hub and could find work as soon as we wrote FLAG_CF.)
 	 *
-	 * Before this point the HC was idle/ready.  After, khubd
+	 * Before this point the HC was idle/ready.  After, hub_wq
 	 * and device drivers may start it running.
 	 */
 	fhci_usb_enable(fhci);