OHCI: add auto-stop support
This patch (as790b) adds "autostop" support to ohci-hcd: the driver
will automatically stop the host controller when no devices have been
connected for at least one second. This feature is useful when the
USB autosuspend facility isn't available, such as when
CONFIG_USB_SUSPEND hasn't been set.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/host/ohci-hub.c b/drivers/usb/host/ohci-hub.c
index ef49654..f36cbd0 100644
--- a/drivers/usb/host/ohci-hub.c
+++ b/drivers/usb/host/ohci-hub.c
@@ -41,31 +41,20 @@
{
struct ohci_hcd *ohci = hcd_to_ohci (hcd);
- hcd->poll_rh = 0;
ohci_writel (ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
}
-#ifdef CONFIG_PM
-
#define OHCI_SCHED_ENABLES \
(OHCI_CTRL_CLE|OHCI_CTRL_BLE|OHCI_CTRL_PLE|OHCI_CTRL_IE)
static void dl_done_list (struct ohci_hcd *, struct pt_regs *);
static void finish_unlinks (struct ohci_hcd *, u16 , struct pt_regs *);
-static int ohci_restart (struct ohci_hcd *ohci);
-static int ohci_bus_suspend (struct usb_hcd *hcd)
+static int ohci_rh_suspend (struct ohci_hcd *ohci, int autostop)
+__releases(ohci->lock)
+__acquires(ohci->lock)
{
- struct ohci_hcd *ohci = hcd_to_ohci (hcd);
int status = 0;
- unsigned long flags;
-
- spin_lock_irqsave (&ohci->lock, flags);
-
- if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))) {
- spin_unlock_irqrestore (&ohci->lock, flags);
- return -ESHUTDOWN;
- }
ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
switch (ohci->hc_control & OHCI_CTRL_HCFS) {
@@ -81,15 +70,16 @@
ohci_dbg (ohci, "needs reinit!\n");
goto done;
case OHCI_USB_SUSPEND:
- ohci_dbg (ohci, "already suspended\n");
- goto done;
+ if (!ohci->autostop) {
+ ohci_dbg (ohci, "already suspended\n");
+ goto done;
+ }
}
- ohci_dbg (ohci, "suspend root hub\n");
+ ohci_dbg (ohci, "%s root hub\n",
+ autostop ? "auto-stop" : "suspend");
/* First stop any processing */
- if (ohci->hc_control & OHCI_SCHED_ENABLES) {
- int limit;
-
+ if (!autostop && (ohci->hc_control & OHCI_SCHED_ENABLES)) {
ohci->hc_control &= ~OHCI_SCHED_ENABLES;
ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
@@ -99,24 +89,17 @@
* then the last WDH could take 6+ msec
*/
ohci_dbg (ohci, "stopping schedules ...\n");
- limit = 2000;
- while (limit > 0) {
- udelay (250);
- limit =- 250;
- if (ohci_readl (ohci, &ohci->regs->intrstatus)
- & OHCI_INTR_SF)
- break;
- }
- dl_done_list (ohci, NULL);
- mdelay (7);
+ ohci->autostop = 0;
+ spin_unlock_irq (&ohci->lock);
+ msleep (8);
+ spin_lock_irq (&ohci->lock);
}
dl_done_list (ohci, NULL);
finish_unlinks (ohci, ohci_frame_no(ohci), NULL);
- ohci_writel (ohci, ohci_readl (ohci, &ohci->regs->intrstatus),
- &ohci->regs->intrstatus);
/* maybe resume can wake root hub */
- if (device_may_wakeup(&ohci_to_hcd(ohci)->self.root_hub->dev))
+ if (device_may_wakeup(&ohci_to_hcd(ohci)->self.root_hub->dev) ||
+ autostop)
ohci->hc_control |= OHCI_CTRL_RWE;
else {
ohci_writel (ohci, OHCI_INTR_RHSC, &ohci->regs->intrdisable);
@@ -132,13 +115,12 @@
(void) ohci_readl (ohci, &ohci->regs->control);
/* no resumes until devices finish suspending */
- ohci->next_statechange = jiffies + msecs_to_jiffies (5);
-
- /* no timer polling */
- hcd->poll_rh = 0;
+ if (!autostop) {
+ ohci->next_statechange = jiffies + msecs_to_jiffies (5);
+ ohci->autostop = 0;
+ }
done:
- spin_unlock_irqrestore (&ohci->lock, flags);
return status;
}
@@ -151,24 +133,16 @@
}
/* caller has locked the root hub */
-static int ohci_bus_resume (struct usb_hcd *hcd)
+static int ohci_rh_resume (struct ohci_hcd *ohci)
+__releases(ohci->lock)
+__acquires(ohci->lock)
{
- struct ohci_hcd *ohci = hcd_to_ohci (hcd);
+ struct usb_hcd *hcd = ohci_to_hcd (ohci);
u32 temp, enables;
int status = -EINPROGRESS;
- unsigned long flags;
+ int autostopped = ohci->autostop;
- if (time_before (jiffies, ohci->next_statechange))
- msleep(5);
-
- spin_lock_irqsave (&ohci->lock, flags);
-
- if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))) {
- spin_unlock_irqrestore (&ohci->lock, flags);
- return -ESHUTDOWN;
- }
-
-
+ ohci->autostop = 0;
ohci->hc_control = ohci_readl (ohci, &ohci->regs->control);
if (ohci->hc_control & (OHCI_CTRL_IR | OHCI_SCHED_ENABLES)) {
@@ -188,7 +162,8 @@
ohci->hc_control |= OHCI_USB_RESUME;
ohci_writel (ohci, ohci->hc_control, &ohci->regs->control);
(void) ohci_readl (ohci, &ohci->regs->control);
- ohci_dbg (ohci, "resume root hub\n");
+ ohci_dbg (ohci, "%s root hub\n",
+ autostopped ? "auto-start" : "resume");
break;
case OHCI_USB_RESUME:
/* HCFS changes sometime after INTR_RD */
@@ -203,16 +178,26 @@
ohci_dbg (ohci, "lost power\n");
status = -EBUSY;
}
- spin_unlock_irqrestore (&ohci->lock, flags);
+#ifdef CONFIG_PM
if (status == -EBUSY) {
- (void) ohci_init (ohci);
- return ohci_restart (ohci);
+ if (!autostopped) {
+ static int ohci_restart (struct ohci_hcd *ohci);
+
+ spin_unlock_irq (&ohci->lock);
+ (void) ohci_init (ohci);
+ status = ohci_restart (ohci);
+ spin_lock_irq (&ohci->lock);
+ }
+ return status;
}
+#endif
if (status != -EINPROGRESS)
return status;
+ if (autostopped)
+ goto skip_resume;
+ spin_unlock_irq (&ohci->lock);
temp = ohci->num_ports;
- enables = 0;
while (temp--) {
u32 stat = ohci_readl (ohci,
&ohci->regs->roothub.portstatus [temp]);
@@ -245,17 +230,21 @@
/* Sometimes PCI D3 suspend trashes frame timings ... */
periodic_reinit (ohci);
+ /* the following code is executed with ohci->lock held and
+ * irqs disabled if and only if autostopped is true
+ */
+
+skip_resume:
/* interrupts might have been disabled */
ohci_writel (ohci, OHCI_INTR_INIT, &ohci->regs->intrenable);
if (ohci->ed_rm_list)
ohci_writel (ohci, OHCI_INTR_SF, &ohci->regs->intrenable);
- ohci_writel (ohci, ohci_readl (ohci, &ohci->regs->intrstatus),
- &ohci->regs->intrstatus);
/* Then re-enable operations */
ohci_writel (ohci, OHCI_USB_OPER, &ohci->regs->control);
(void) ohci_readl (ohci, &ohci->regs->control);
- msleep (3);
+ if (!autostopped)
+ msleep (3);
temp = ohci->hc_control;
temp &= OHCI_CTRL_RWC;
@@ -265,7 +254,11 @@
(void) ohci_readl (ohci, &ohci->regs->control);
/* TRSMRCY */
- msleep (10);
+ if (!autostopped) {
+ msleep (10);
+ spin_lock_irq (&ohci->lock);
+ }
+ /* now ohci->lock is always held and irqs are always disabled */
/* keep it alive for more than ~5x suspend + resume costs */
ohci->next_statechange = jiffies + STATECHANGE_DELAY;
@@ -302,6 +295,45 @@
return 0;
}
+#ifdef CONFIG_PM
+
+static int ohci_bus_suspend (struct usb_hcd *hcd)
+{
+ struct ohci_hcd *ohci = hcd_to_ohci (hcd);
+ int rc;
+
+ spin_lock_irq (&ohci->lock);
+
+ if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)))
+ rc = -ESHUTDOWN;
+ else
+ rc = ohci_rh_suspend (ohci, 0);
+ spin_unlock_irq (&ohci->lock);
+ return rc;
+}
+
+static int ohci_bus_resume (struct usb_hcd *hcd)
+{
+ struct ohci_hcd *ohci = hcd_to_ohci (hcd);
+ int rc;
+
+ if (time_before (jiffies, ohci->next_statechange))
+ msleep(5);
+
+ spin_lock_irq (&ohci->lock);
+
+ if (unlikely(!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)))
+ rc = -ESHUTDOWN;
+ else
+ rc = ohci_rh_resume (ohci);
+ spin_unlock_irq (&ohci->lock);
+
+ /* poll until we know a device is connected or we autostop */
+ if (rc == 0)
+ usb_hcd_poll_rh_status(hcd);
+ return rc;
+}
+
#endif /* CONFIG_PM */
/*-------------------------------------------------------------------------*/
@@ -313,17 +345,11 @@
{
struct ohci_hcd *ohci = hcd_to_ohci (hcd);
int i, changed = 0, length = 1;
+ int any_connected = 0, rhsc_enabled = 1;
unsigned long flags;
spin_lock_irqsave (&ohci->lock, flags);
- /* handle autosuspended root: finish resuming before
- * letting khubd or root hub timer see state changes.
- */
- if (unlikely((ohci->hc_control & OHCI_CTRL_HCFS) != OHCI_USB_OPER
- || !HC_IS_RUNNING(hcd->state)))
- goto done;
-
/* undocumented erratum seen on at least rev D */
if ((ohci->flags & OHCI_QUIRK_AMD756)
&& (roothub_a (ohci) & RH_A_NDP) > MAX_ROOT_PORTS) {
@@ -347,6 +373,9 @@
for (i = 0; i < ohci->num_ports; i++) {
u32 status = roothub_portstatus (ohci, i);
+ /* can't autostop if ports are connected */
+ any_connected |= (status & RH_PS_CCS);
+
if (status & (RH_PS_CSC | RH_PS_PESC | RH_PS_PSSC
| RH_PS_OCIC | RH_PS_PRSC)) {
changed = 1;
@@ -354,15 +383,69 @@
buf [0] |= 1 << (i + 1);
else
buf [1] |= 1 << (i - 7);
- continue;
}
}
- /* after root hub changes, stop polling after debouncing
- * for a while and maybe kicking in autosuspend
+ /* NOTE: vendors didn't always make the same implementation
+ * choices for RHSC. Sometimes it triggers on an edge (like
+ * setting and maybe clearing a port status change bit); and
+ * it's level-triggered on other silicon, active until khubd
+ * clears all active port status change bits. If it's still
+ * set (level-triggered) we must disable it and rely on
+ * polling until khubd re-enables it.
*/
- if (changed)
- ohci->next_statechange = jiffies + STATECHANGE_DELAY;
+ if (ohci_readl (ohci, &ohci->regs->intrstatus) & OHCI_INTR_RHSC) {
+ ohci_writel (ohci, OHCI_INTR_RHSC, &ohci->regs->intrdisable);
+ (void) ohci_readl (ohci, &ohci->regs->intrdisable);
+ rhsc_enabled = 0;
+ }
+ hcd->poll_rh = 1;
+
+ /* carry out appropriate state changes */
+ switch (ohci->hc_control & OHCI_CTRL_HCFS) {
+
+ case OHCI_USB_OPER:
+ /* keep on polling until we know a device is connected
+ * and RHSC is enabled */
+ if (!ohci->autostop) {
+ if (any_connected) {
+ if (rhsc_enabled)
+ hcd->poll_rh = 0;
+ } else {
+ ohci->autostop = 1;
+ ohci->next_statechange = jiffies + HZ;
+ }
+
+ /* if no devices have been attached for one second, autostop */
+ } else {
+ if (changed || any_connected) {
+ ohci->autostop = 0;
+ ohci->next_statechange = jiffies +
+ STATECHANGE_DELAY;
+ } else if (time_after_eq (jiffies,
+ ohci->next_statechange)
+ && !ohci->ed_rm_list
+ && !(ohci->hc_control &
+ OHCI_SCHED_ENABLES)) {
+ ohci_rh_suspend (ohci, 1);
+ }
+ }
+ break;
+
+ /* if there is a port change, autostart or ask to be resumed */
+ case OHCI_USB_SUSPEND:
+ case OHCI_USB_RESUME:
+ if (changed) {
+ if (ohci->autostop)
+ ohci_rh_resume (ohci);
+ else
+ usb_hcd_resume_root_hub (hcd);
+ } else {
+ /* everything is idle, no need for polling */
+ hcd->poll_rh = 0;
+ }
+ break;
+ }
done:
spin_unlock_irqrestore (&ohci->lock, flags);