USB: EHCI: remove usages of hcd->state

This patch (as1483) improves the ehci-hcd driver family by getting rid
of the reliance on the hcd->state variable.  It has no clear owner and
it isn't protected by the usual HCD locks.  In its place, the patch
adds a new, private ehci->rh_state field to record the state of the
root hub.

Along the way, the patch removes a couple of lines containing
redundant assignments to the state variable.  Also, the QUIESCING
state simply gets changed to the RUNNING state, because the driver
doesn't make any distinction between them.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/host/ehci-au1xxx.c

@@ -293,7 +293,7 @@ static int ehci_hcd_au1xxx_drv_resume(struct device *dev)
 	/* here we "know" root ports should always stay powered */
 	ehci_port_power(ehci, 1);
 
-	hcd->state = HC_STATE_SUSPENDED;
+	ehci->rh_state = EHCI_RH_SUSPENDED;
 
 	return 0;
 }

drivers/usb/host/ehci-dbg.c

@@ -697,6 +697,19 @@ static ssize_t fill_periodic_buffer(struct debug_buffer *buf)
 }
 #undef DBG_SCHED_LIMIT
 
+static const char *rh_state_string(struct ehci_hcd *ehci)
+{
+	switch (ehci->rh_state) {
+	case EHCI_RH_HALTED:
+		return "halted";
+	case EHCI_RH_SUSPENDED:
+		return "suspended";
+	case EHCI_RH_RUNNING:
+		return "running";
+	}
+	return "?";
+}
+
 static ssize_t fill_registers_buffer(struct debug_buffer *buf)
 {
 	struct usb_hcd		*hcd;
@@ -730,11 +743,11 @@ static ssize_t fill_registers_buffer(struct debug_buffer *buf)
 	temp = scnprintf (next, size,
 		"bus %s, device %s\n"
 		"%s\n"
-		"EHCI %x.%02x, hcd state %d\n",
+		"EHCI %x.%02x, rh state %s\n",
 		hcd->self.controller->bus->name,
 		dev_name(hcd->self.controller),
 		hcd->product_desc,
-		i >> 8, i & 0x0ff, hcd->state);
+		i >> 8, i & 0x0ff, rh_state_string(ehci));
 	size -= temp;
 	next += temp;
 

drivers/usb/host/ehci-fsl.c

@@ -392,7 +392,7 @@ static int ehci_fsl_mpc512x_drv_suspend(struct device *dev)
 
 	dev_dbg(dev, "suspending...\n");
 
-	hcd->state = HC_STATE_SUSPENDED;
+	ehci->rh_state = EHCI_RH_SUSPENDED;
 	dev->power.power_state = PMSG_SUSPEND;
 
 	/* ignore non-host interrupts */
@@ -481,7 +481,7 @@ static int ehci_fsl_mpc512x_drv_resume(struct device *dev)
 	ehci_writel(ehci, pdata->pm_portsc, &ehci->regs->port_status[0]);
 
 	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
-	hcd->state = HC_STATE_RUNNING;
+	ehci->rh_state = EHCI_RH_RUNNING;
 	dev->power.power_state = PMSG_ON;
 
 	tmp = ehci_readl(ehci, &ehci->regs->command);

drivers/usb/host/ehci-hcd.c

@@ -238,7 +238,7 @@ static int handshake_on_error_set_halt(struct ehci_hcd *ehci, void __iomem *ptr,
 	error = handshake(ehci, ptr, mask, done, usec);
 	if (error) {
 		ehci_halt(ehci);
-		ehci_to_hcd(ehci)->state = HC_STATE_HALT;
+		ehci->rh_state = EHCI_RH_HALTED;
 		ehci_err(ehci, "force halt; handshake %p %08x %08x -> %d\n",
 			ptr, mask, done, error);
 	}
@@ -278,7 +278,7 @@ static int ehci_reset (struct ehci_hcd *ehci)
 	command |= CMD_RESET;
 	dbg_cmd (ehci, "reset", command);
 	ehci_writel(ehci, command, &ehci->regs->command);
-	ehci_to_hcd(ehci)->state = HC_STATE_HALT;
+	ehci->rh_state = EHCI_RH_HALTED;
 	ehci->next_statechange = jiffies;
 	retval = handshake (ehci, &ehci->regs->command,
 			    CMD_RESET, 0, 250 * 1000);
@@ -307,7 +307,7 @@ static void ehci_quiesce (struct ehci_hcd *ehci)
 	u32	temp;
 
 #ifdef DEBUG
-	if (!HC_IS_RUNNING (ehci_to_hcd(ehci)->state))
+	if (ehci->rh_state != EHCI_RH_RUNNING)
 		BUG ();
 #endif
 
@@ -356,7 +356,7 @@ static void ehci_iaa_watchdog(unsigned long param)
 	 */
 	if (ehci->reclaim
 			&& !timer_pending(&ehci->iaa_watchdog)
-			&& HC_IS_RUNNING(ehci_to_hcd(ehci)->state)) {
+			&& ehci->rh_state == EHCI_RH_RUNNING) {
 		u32 cmd, status;
 
 		/* If we get here, IAA is *REALLY* late.  It's barely
@@ -496,7 +496,7 @@ static void ehci_work (struct ehci_hcd *ehci)
 	 * misplace IRQs, and should let us run completely without IRQs.
 	 * such lossage has been observed on both VT6202 and VT8235.
 	 */
-	if (HC_IS_RUNNING (ehci_to_hcd(ehci)->state) &&
+	if (ehci->rh_state == EHCI_RH_RUNNING &&
 			(ehci->async->qh_next.ptr != NULL ||
 			 ehci->periodic_sched != 0))
 		timer_action (ehci, TIMER_IO_WATCHDOG);
@@ -516,7 +516,7 @@ static void ehci_stop (struct usb_hcd *hcd)
 	del_timer_sync(&ehci->iaa_watchdog);
 
 	spin_lock_irq(&ehci->lock);
-	if (HC_IS_RUNNING (hcd->state))
+	if (ehci->rh_state == EHCI_RH_RUNNING)
 		ehci_quiesce (ehci);
 
 	ehci_silence_controller(ehci);
@@ -741,7 +741,7 @@ static int ehci_run (struct usb_hcd *hcd)
 	 * be started before the port switching actions could complete.
 	 */
 	down_write(&ehci_cf_port_reset_rwsem);
-	hcd->state = HC_STATE_RUNNING;
+	ehci->rh_state = EHCI_RH_RUNNING;
 	ehci_writel(ehci, FLAG_CF, &ehci->regs->configured_flag);
 	ehci_readl(ehci, &ehci->regs->command);	/* unblock posted writes */
 	msleep(5);
@@ -788,7 +788,7 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
 
 	/* Shared IRQ? */
 	masked_status = status & INTR_MASK;
-	if (!masked_status || unlikely(hcd->state == HC_STATE_HALT)) {
+	if (!masked_status || unlikely(ehci->rh_state == EHCI_RH_HALTED)) {
 		spin_unlock(&ehci->lock);
 		return IRQ_NONE;
 	}
@@ -952,7 +952,7 @@ static int ehci_urb_enqueue (
 static void unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
 {
 	/* failfast */
-	if (!HC_IS_RUNNING(ehci_to_hcd(ehci)->state) && ehci->reclaim)
+	if (ehci->rh_state != EHCI_RH_RUNNING && ehci->reclaim)
 		end_unlink_async(ehci);
 
 	/* If the QH isn't linked then there's nothing we can do
@@ -1079,7 +1079,7 @@ rescan:
 		goto idle_timeout;
 	}
 
-	if (!HC_IS_RUNNING (hcd->state))
+	if (ehci->rh_state != EHCI_RH_RUNNING)
 		qh->qh_state = QH_STATE_IDLE;
 	switch (qh->qh_state) {
 	case QH_STATE_LINKED:

drivers/usb/host/ehci-hub.c

@@ -236,10 +236,8 @@ static int ehci_bus_suspend (struct usb_hcd *hcd)
 	}
 
 	/* stop schedules, clean any completed work */
-	if (HC_IS_RUNNING(hcd->state)) {
+	if (ehci->rh_state == EHCI_RH_RUNNING)
 		ehci_quiesce (ehci);
-		hcd->state = HC_STATE_QUIESCING;
-	}
 	ehci->command = ehci_readl(ehci, &ehci->regs->command);
 	ehci_work(ehci);
 
@@ -313,7 +311,7 @@ static int ehci_bus_suspend (struct usb_hcd *hcd)
 
 	/* turn off now-idle HC */
 	ehci_halt (ehci);
-	hcd->state = HC_STATE_SUSPENDED;
+	ehci->rh_state = EHCI_RH_SUSPENDED;
 
 	if (ehci->reclaim)
 		end_unlink_async(ehci);
@@ -382,6 +380,7 @@ static int ehci_bus_resume (struct usb_hcd *hcd)
 
 	/* restore CMD_RUN, framelist size, and irq threshold */
 	ehci_writel(ehci, ehci->command, &ehci->regs->command);
+	ehci->rh_state = EHCI_RH_RUNNING;
 
 	/* Some controller/firmware combinations need a delay during which
 	 * they set up the port statuses.  See Bugzilla #8190. */
@@ -452,7 +451,6 @@ static int ehci_bus_resume (struct usb_hcd *hcd)
 	}
 
 	ehci->next_statechange = jiffies + msecs_to_jiffies(5);
-	hcd->state = HC_STATE_RUNNING;
 
 	/* Now we can safely re-enable irqs */
 	ehci_writel(ehci, INTR_MASK, &ehci->regs->intr_enable);
@@ -564,7 +562,7 @@ ehci_hub_status_data (struct usb_hcd *hcd, char *buf)
 	u32		ppcd = 0;
 
 	/* if !USB_SUSPEND, root hub timers won't get shut down ... */
-	if (!HC_IS_RUNNING(hcd->state))
+	if (ehci->rh_state != EHCI_RH_RUNNING)
 		return 0;
 
 	/* init status to no-changes */

drivers/usb/host/ehci-pci.c

@@ -439,7 +439,7 @@ static int ehci_pci_resume(struct usb_hcd *hcd, bool hibernated)
 	/* here we "know" root ports should always stay powered */
 	ehci_port_power(ehci, 1);
 
-	hcd->state = HC_STATE_SUSPENDED;
+	ehci->rh_state = EHCI_RH_SUSPENDED;
 	return 0;
 }
 #endif

drivers/usb/host/ehci-q.c

@@ -153,7 +153,7 @@ static void ehci_clear_tt_buffer_complete(struct usb_hcd *hcd,
 	spin_lock_irqsave(&ehci->lock, flags);
 	qh->clearing_tt = 0;
 	if (qh->qh_state == QH_STATE_IDLE && !list_empty(&qh->qtd_list)
-			&& HC_IS_RUNNING(hcd->state))
+			&& ehci->rh_state == EHCI_RH_RUNNING)
 		qh_link_async(ehci, qh);
 	spin_unlock_irqrestore(&ehci->lock, flags);
 }
@@ -425,7 +425,7 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
 
 		/* stop scanning when we reach qtds the hc is using */
 		} else if (likely (!stopped
-				&& HC_IS_RUNNING (ehci_to_hcd(ehci)->state))) {
+				&& ehci->rh_state == EHCI_RH_RUNNING)) {
 			break;
 
 		/* scan the whole queue for unlinks whenever it stops */
@@ -433,7 +433,7 @@ qh_completions (struct ehci_hcd *ehci, struct ehci_qh *qh)
 			stopped = 1;
 
 			/* cancel everything if we halt, suspend, etc */
-			if (!HC_IS_RUNNING(ehci_to_hcd(ehci)->state))
+			if (ehci->rh_state != EHCI_RH_RUNNING)
 				last_status = -ESHUTDOWN;
 
 			/* this qtd is active; skip it unless a previous qtd
@@ -977,9 +977,8 @@ static void qh_link_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
 			/* in case a clear of CMD_ASE didn't take yet */
 			(void)handshake(ehci, &ehci->regs->status,
 					STS_ASS, 0, 150);
-			cmd |= CMD_ASE | CMD_RUN;
+			cmd |= CMD_ASE;
 			ehci_writel(ehci, cmd, &ehci->regs->command);
-			ehci_to_hcd(ehci)->state = HC_STATE_RUNNING;
 			/* posted write need not be known to HC yet ... */
 		}
 	}
@@ -1168,14 +1167,13 @@ static void end_unlink_async (struct ehci_hcd *ehci)
 
 	qh_completions (ehci, qh);
 
-	if (!list_empty (&qh->qtd_list)
-			&& HC_IS_RUNNING (ehci_to_hcd(ehci)->state))
+	if (!list_empty(&qh->qtd_list) && ehci->rh_state == EHCI_RH_RUNNING) {
 		qh_link_async (ehci, qh);
-	else {
+	} else {
 		/* it's not free to turn the async schedule on/off; leave it
 		 * active but idle for a while once it empties.
 		 */
-		if (HC_IS_RUNNING (ehci_to_hcd(ehci)->state)
+		if (ehci->rh_state == EHCI_RH_RUNNING
 				&& ehci->async->qh_next.qh == NULL)
 			timer_action (ehci, TIMER_ASYNC_OFF);
 	}
@@ -1211,7 +1209,7 @@ static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
 	/* stop async schedule right now? */
 	if (unlikely (qh == ehci->async)) {
 		/* can't get here without STS_ASS set */
-		if (ehci_to_hcd(ehci)->state != HC_STATE_HALT
+		if (ehci->rh_state != EHCI_RH_HALTED
 				&& !ehci->reclaim) {
 			/* ... and CMD_IAAD clear */
 			ehci_writel(ehci, cmd & ~CMD_ASE,
@@ -1237,7 +1235,7 @@ static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
 	wmb ();
 
 	/* If the controller isn't running, we don't have to wait for it */
-	if (unlikely(!HC_IS_RUNNING(ehci_to_hcd(ehci)->state))) {
+	if (unlikely(ehci->rh_state != EHCI_RH_RUNNING)) {
 		/* if (unlikely (qh->reclaim != 0))
 		 *	this will recurse, probably not much
 		 */
@@ -1260,7 +1258,7 @@ static void scan_async (struct ehci_hcd *ehci)
 	enum ehci_timer_action	action = TIMER_IO_WATCHDOG;
 
 	timer_action_done (ehci, TIMER_ASYNC_SHRINK);
-	stopped = !HC_IS_RUNNING(ehci_to_hcd(ehci)->state);
+	stopped = (ehci->rh_state != EHCI_RH_RUNNING);
 
 	ehci->qh_scan_next = ehci->async->qh_next.qh;
 	while (ehci->qh_scan_next) {

drivers/usb/host/ehci-s5p.c

@@ -269,7 +269,7 @@ static int s5p_ehci_resume(struct device *dev)
 	/* here we "know" root ports should always stay powered */
 	ehci_port_power(ehci, 1);
 
-	hcd->state = HC_STATE_SUSPENDED;
+	ehci->rh_state = EHCI_RH_SUSPENDED;
 
 	return 0;
 }

drivers/usb/host/ehci-sched.c

@@ -479,7 +479,6 @@ static int enable_periodic (struct ehci_hcd *ehci)
 	cmd = ehci_readl(ehci, &ehci->regs->command) | CMD_PSE;
 	ehci_writel(ehci, cmd, &ehci->regs->command);
 	/* posted write ... PSS happens later */
-	ehci_to_hcd(ehci)->state = HC_STATE_RUNNING;
 
 	/* make sure ehci_work scans these */
 	ehci->next_uframe = ehci_readl(ehci, &ehci->regs->frame_index)
@@ -677,7 +676,7 @@ static void intr_deschedule (struct ehci_hcd *ehci, struct ehci_qh *qh)
 
 	/* reschedule QH iff another request is queued */
 	if (!list_empty(&qh->qtd_list) &&
-			HC_IS_RUNNING(ehci_to_hcd(ehci)->state)) {
+			ehci->rh_state == EHCI_RH_RUNNING) {
 		rc = qh_schedule(ehci, qh);
 
 		/* An error here likely indicates handshake failure
@@ -2275,7 +2274,7 @@ scan_periodic (struct ehci_hcd *ehci)
 	 * Touches as few pages as possible:  cache-friendly.
 	 */
 	now_uframe = ehci->next_uframe;
-	if (HC_IS_RUNNING(ehci_to_hcd(ehci)->state)) {
+	if (ehci->rh_state == EHCI_RH_RUNNING) {
 		clock = ehci_readl(ehci, &ehci->regs->frame_index);
 		clock_frame = (clock >> 3) & (ehci->periodic_size - 1);
 	} else  {
@@ -2310,7 +2309,7 @@ restart:
 			union ehci_shadow	temp;
 			int			live;
 
-			live = HC_IS_RUNNING (ehci_to_hcd(ehci)->state);
+			live = (ehci->rh_state == EHCI_RH_RUNNING);
 			switch (hc32_to_cpu(ehci, type)) {
 			case Q_TYPE_QH:
 				/* handle any completions */
@@ -2435,7 +2434,7 @@ restart:
 		 * We can't advance our scan without collecting the ISO
 		 * transfers that are still pending in this frame.
 		 */
-		if (incomplete && HC_IS_RUNNING(ehci_to_hcd(ehci)->state)) {
+		if (incomplete && ehci->rh_state == EHCI_RH_RUNNING) {
 			ehci->next_uframe = now_uframe;
 			break;
 		}
@@ -2451,7 +2450,7 @@ restart:
 		if (now_uframe == clock) {
 			unsigned	now;
 
-			if (!HC_IS_RUNNING (ehci_to_hcd(ehci)->state)
+			if (ehci->rh_state != EHCI_RH_RUNNING
 					|| ehci->periodic_sched == 0)
 				break;
 			ehci->next_uframe = now_uframe;

drivers/usb/host/ehci.h

@@ -62,6 +62,12 @@ struct ehci_stats {
 
 #define	EHCI_MAX_ROOT_PORTS	15		/* see HCS_N_PORTS */
 
+enum ehci_rh_state {
+	EHCI_RH_HALTED,
+	EHCI_RH_SUSPENDED,
+	EHCI_RH_RUNNING
+};
+
 struct ehci_hcd {			/* one per controller */
 	/* glue to PCI and HCD framework */
 	struct ehci_caps __iomem *caps;
@@ -70,6 +76,7 @@ struct ehci_hcd {			/* one per controller */
 
 	__u32			hcs_params;	/* cached register copy */
 	spinlock_t		lock;
+	enum ehci_rh_state	rh_state;
 
 	/* async schedule support */
 	struct ehci_qh		*async;