USB: automatically enable RHSC interrupts
This patch (as1069c) changes the way OHCI root-hub status-change
interrupts are enabled. Currently a special HCD method,
hub_irq_enable(), is called when the hub driver is finished using a
root hub. This approach turns out to be subject to races, resulting
in unnecessary polling.
The patch does away with the method entirely. Instead, the driver
automatically enables the RHSC interrupt when no more status changes
are present. This scheme is safe with controllers using
level-triggered semantics for their interrupt flags.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index f7bfd72..8abd4e5 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -924,15 +924,6 @@
return retval;
}
-void usb_enable_root_hub_irq (struct usb_bus *bus)
-{
- struct usb_hcd *hcd;
-
- hcd = container_of (bus, struct usb_hcd, self);
- if (hcd->driver->hub_irq_enable && hcd->state != HC_STATE_HALT)
- hcd->driver->hub_irq_enable (hcd);
-}
-
/*-------------------------------------------------------------------------*/
diff --git a/drivers/usb/core/hcd.h b/drivers/usb/core/hcd.h
index 5b0b59b..e710ce0 100644
--- a/drivers/usb/core/hcd.h
+++ b/drivers/usb/core/hcd.h
@@ -212,8 +212,6 @@
int (*bus_suspend)(struct usb_hcd *);
int (*bus_resume)(struct usb_hcd *);
int (*start_port_reset)(struct usb_hcd *, unsigned port_num);
- void (*hub_irq_enable)(struct usb_hcd *);
- /* Needed only if port-change IRQs are level-triggered */
/* force handover of high-speed port to full-speed companion */
void (*relinquish_port)(struct usb_hcd *, int);
@@ -379,8 +377,6 @@
extern struct mutex usb_bus_list_lock;
extern wait_queue_head_t usb_kill_urb_queue;
-extern void usb_enable_root_hub_irq(struct usb_bus *bus);
-
extern int usb_find_interface_driver(struct usb_device *dev,
struct usb_interface *interface);
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 107e1d2..6a5cb01 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2102,8 +2102,6 @@
}
clear_bit(port1, hub->busy_bits);
- if (!hub->hdev->parent && !hub->busy_bits[0])
- usb_enable_root_hub_irq(hub->hdev->bus);
status = check_port_resume_type(udev,
hub, port1, status, portchange, portstatus);
@@ -3081,11 +3079,6 @@
}
}
- /* If this is a root hub, tell the HCD it's okay to
- * re-enable port-change interrupts now. */
- if (!hdev->parent && !hub->busy_bits[0])
- usb_enable_root_hub_irq(hdev->bus);
-
loop_autopm:
/* Allow autosuspend if we're not going to run again */
if (list_empty(&hub->event_list))
@@ -3311,8 +3304,6 @@
break;
}
clear_bit(port1, parent_hub->busy_bits);
- if (!parent_hdev->parent && !parent_hub->busy_bits[0])
- usb_enable_root_hub_irq(parent_hdev->bus);
if (ret < 0)
goto re_enumerate;
diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c
index 6db7a28..4ed228a 100644
--- a/drivers/usb/host/ohci-at91.c
+++ b/drivers/usb/host/ohci-at91.c
@@ -260,7 +260,6 @@
*/
.hub_status_data = ohci_hub_status_data,
.hub_control = ohci_hub_control,
- .hub_irq_enable = ohci_rhsc_enable,
#ifdef CONFIG_PM
.bus_suspend = ohci_bus_suspend,
.bus_resume = ohci_bus_resume,
diff --git a/drivers/usb/host/ohci-au1xxx.c b/drivers/usb/host/ohci-au1xxx.c
index c094800..2ac4e02 100644
--- a/drivers/usb/host/ohci-au1xxx.c
+++ b/drivers/usb/host/ohci-au1xxx.c
@@ -163,7 +163,6 @@
*/
.hub_status_data = ohci_hub_status_data,
.hub_control = ohci_hub_control,
- .hub_irq_enable = ohci_rhsc_enable,
#ifdef CONFIG_PM
.bus_suspend = ohci_bus_suspend,
.bus_resume = ohci_bus_resume,
diff --git a/drivers/usb/host/ohci-ep93xx.c b/drivers/usb/host/ohci-ep93xx.c
index cb0b506..fb3055f 100644
--- a/drivers/usb/host/ohci-ep93xx.c
+++ b/drivers/usb/host/ohci-ep93xx.c
@@ -134,7 +134,6 @@
.get_frame_number = ohci_get_frame,
.hub_status_data = ohci_hub_status_data,
.hub_control = ohci_hub_control,
- .hub_irq_enable = ohci_rhsc_enable,
#ifdef CONFIG_PM
.bus_suspend = ohci_bus_suspend,
.bus_resume = ohci_bus_resume,
diff --git a/drivers/usb/host/ohci-hub.c b/drivers/usb/host/ohci-hub.c
index 439beb7..7ea9a7b 100644
--- a/drivers/usb/host/ohci-hub.c
+++ b/drivers/usb/host/ohci-hub.c
@@ -36,18 +36,6 @@
/*-------------------------------------------------------------------------*/
-/* hcd->hub_irq_enable() */
-static void ohci_rhsc_enable (struct usb_hcd *hcd)
-{
- struct ohci_hcd *ohci = hcd_to_ohci (hcd);
-
- spin_lock_irq(&ohci->lock);
- if (!ohci->autostop)
- del_timer(&hcd->rh_timer); /* Prevent next poll */
- ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
- spin_unlock_irq(&ohci->lock);
-}
-
#define OHCI_SCHED_ENABLES \
(OHCI_CTRL_CLE|OHCI_CTRL_BLE|OHCI_CTRL_PLE|OHCI_CTRL_IE)
@@ -374,18 +362,28 @@
int any_connected)
{
int poll_rh = 1;
+ int rhsc;
+ rhsc = ohci_readl(ohci, &ohci->regs->intrenable) & OHCI_INTR_RHSC;
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 no status changes are pending, enable status-change
+ * interrupts.
+ */
+ if (!rhsc && !changed) {
+ rhsc = OHCI_INTR_RHSC;
+ ohci_writel(ohci, rhsc, &ohci->regs->intrenable);
+ }
+
+ /* Keep on polling until we know a device is connected
+ * and RHSC is enabled, or until we autostop.
+ */
if (!ohci->autostop) {
if (any_connected ||
!device_may_wakeup(&ohci_to_hcd(ohci)
->self.root_hub->dev)) {
- if (ohci_readl(ohci, &ohci->regs->intrenable) &
- OHCI_INTR_RHSC)
+ if (rhsc)
poll_rh = 0;
} else {
ohci->autostop = 1;
@@ -398,12 +396,13 @@
ohci->autostop = 0;
ohci->next_statechange = jiffies +
STATECHANGE_DELAY;
- } else if (time_after_eq(jiffies,
+ } else if (rhsc && time_after_eq(jiffies,
ohci->next_statechange)
&& !ohci->ed_rm_list
&& !(ohci->hc_control &
OHCI_SCHED_ENABLES)) {
ohci_rh_suspend(ohci, 1);
+ poll_rh = 0;
}
}
break;
@@ -417,6 +416,12 @@
else
usb_hcd_resume_root_hub(ohci_to_hcd(ohci));
} else {
+ if (!rhsc && (ohci->autostop ||
+ ohci_to_hcd(ohci)->self.root_hub->
+ do_remote_wakeup))
+ ohci_writel(ohci, OHCI_INTR_RHSC,
+ &ohci->regs->intrenable);
+
/* everything is idle, no need for polling */
poll_rh = 0;
}
@@ -438,12 +443,16 @@
static int ohci_root_hub_state_changes(struct ohci_hcd *ohci, int changed,
int any_connected)
{
- int poll_rh = 1;
-
- /* keep on polling until RHSC is enabled */
+ /* If RHSC is enabled, don't poll */
if (ohci_readl(ohci, &ohci->regs->intrenable) & OHCI_INTR_RHSC)
- poll_rh = 0;
- return poll_rh;
+ return 0;
+
+ /* If no status changes are pending, enable status-change interrupts */
+ if (!changed) {
+ ohci_writel(ohci, OHCI_INTR_RHSC, &ohci->regs->intrenable);
+ return 0;
+ }
+ return 1;
}
#endif /* CONFIG_PM */
diff --git a/drivers/usb/host/ohci-lh7a404.c b/drivers/usb/host/ohci-lh7a404.c
index 9e31d44..de42283 100644
--- a/drivers/usb/host/ohci-lh7a404.c
+++ b/drivers/usb/host/ohci-lh7a404.c
@@ -193,7 +193,6 @@
*/
.hub_status_data = ohci_hub_status_data,
.hub_control = ohci_hub_control,
- .hub_irq_enable = ohci_rhsc_enable,
#ifdef CONFIG_PM
.bus_suspend = ohci_bus_suspend,
.bus_resume = ohci_bus_resume,
diff --git a/drivers/usb/host/ohci-omap.c b/drivers/usb/host/ohci-omap.c
index 3d532b7..1eb64d0 100644
--- a/drivers/usb/host/ohci-omap.c
+++ b/drivers/usb/host/ohci-omap.c
@@ -470,7 +470,6 @@
*/
.hub_status_data = ohci_hub_status_data,
.hub_control = ohci_hub_control,
- .hub_irq_enable = ohci_rhsc_enable,
#ifdef CONFIG_PM
.bus_suspend = ohci_bus_suspend,
.bus_resume = ohci_bus_resume,
diff --git a/drivers/usb/host/ohci-pci.c b/drivers/usb/host/ohci-pci.c
index 083e8df..a9c2ae3 100644
--- a/drivers/usb/host/ohci-pci.c
+++ b/drivers/usb/host/ohci-pci.c
@@ -459,7 +459,6 @@
*/
.hub_status_data = ohci_hub_status_data,
.hub_control = ohci_hub_control,
- .hub_irq_enable = ohci_rhsc_enable,
#ifdef CONFIG_PM
.bus_suspend = ohci_bus_suspend,
.bus_resume = ohci_bus_resume,
diff --git a/drivers/usb/host/ohci-pnx4008.c b/drivers/usb/host/ohci-pnx4008.c
index b02cd07..658a2a9 100644
--- a/drivers/usb/host/ohci-pnx4008.c
+++ b/drivers/usb/host/ohci-pnx4008.c
@@ -277,7 +277,6 @@
*/
.hub_status_data = ohci_hub_status_data,
.hub_control = ohci_hub_control,
- .hub_irq_enable = ohci_rhsc_enable,
#ifdef CONFIG_PM
.bus_suspend = ohci_bus_suspend,
.bus_resume = ohci_bus_resume,
diff --git a/drivers/usb/host/ohci-pnx8550.c b/drivers/usb/host/ohci-pnx8550.c
index 605d59c..28467e2 100644
--- a/drivers/usb/host/ohci-pnx8550.c
+++ b/drivers/usb/host/ohci-pnx8550.c
@@ -201,7 +201,6 @@
*/
.hub_status_data = ohci_hub_status_data,
.hub_control = ohci_hub_control,
- .hub_irq_enable = ohci_rhsc_enable,
#ifdef CONFIG_PM
.bus_suspend = ohci_bus_suspend,
.bus_resume = ohci_bus_resume,
diff --git a/drivers/usb/host/ohci-ppc-of.c b/drivers/usb/host/ohci-ppc-of.c
index 91e6e10..7ac5326 100644
--- a/drivers/usb/host/ohci-ppc-of.c
+++ b/drivers/usb/host/ohci-ppc-of.c
@@ -72,7 +72,6 @@
*/
.hub_status_data = ohci_hub_status_data,
.hub_control = ohci_hub_control,
- .hub_irq_enable = ohci_rhsc_enable,
#ifdef CONFIG_PM
.bus_suspend = ohci_bus_suspend,
.bus_resume = ohci_bus_resume,
diff --git a/drivers/usb/host/ohci-ppc-soc.c b/drivers/usb/host/ohci-ppc-soc.c
index 523c301..cd3398b 100644
--- a/drivers/usb/host/ohci-ppc-soc.c
+++ b/drivers/usb/host/ohci-ppc-soc.c
@@ -172,7 +172,6 @@
*/
.hub_status_data = ohci_hub_status_data,
.hub_control = ohci_hub_control,
- .hub_irq_enable = ohci_rhsc_enable,
#ifdef CONFIG_PM
.bus_suspend = ohci_bus_suspend,
.bus_resume = ohci_bus_resume,
diff --git a/drivers/usb/host/ohci-ps3.c b/drivers/usb/host/ohci-ps3.c
index 55c9564..2089d8a 100644
--- a/drivers/usb/host/ohci-ps3.c
+++ b/drivers/usb/host/ohci-ps3.c
@@ -68,7 +68,6 @@
.get_frame_number = ohci_get_frame,
.hub_status_data = ohci_hub_status_data,
.hub_control = ohci_hub_control,
- .hub_irq_enable = ohci_rhsc_enable,
.start_port_reset = ohci_start_port_reset,
#if defined(CONFIG_PM)
.bus_suspend = ohci_bus_suspend,
diff --git a/drivers/usb/host/ohci-pxa27x.c b/drivers/usb/host/ohci-pxa27x.c
index 8c9c484..7f0f35c 100644
--- a/drivers/usb/host/ohci-pxa27x.c
+++ b/drivers/usb/host/ohci-pxa27x.c
@@ -298,7 +298,6 @@
*/
.hub_status_data = ohci_hub_status_data,
.hub_control = ohci_hub_control,
- .hub_irq_enable = ohci_rhsc_enable,
#ifdef CONFIG_PM
.bus_suspend = ohci_bus_suspend,
.bus_resume = ohci_bus_resume,
diff --git a/drivers/usb/host/ohci-s3c2410.c b/drivers/usb/host/ohci-s3c2410.c
index 9e3dc40..f46af7a 100644
--- a/drivers/usb/host/ohci-s3c2410.c
+++ b/drivers/usb/host/ohci-s3c2410.c
@@ -466,7 +466,6 @@
*/
.hub_status_data = ohci_s3c2410_hub_status_data,
.hub_control = ohci_s3c2410_hub_control,
- .hub_irq_enable = ohci_rhsc_enable,
#ifdef CONFIG_PM
.bus_suspend = ohci_bus_suspend,
.bus_resume = ohci_bus_resume,
diff --git a/drivers/usb/host/ohci-sa1111.c b/drivers/usb/host/ohci-sa1111.c
index 4626b00..e4bbe8e 100644
--- a/drivers/usb/host/ohci-sa1111.c
+++ b/drivers/usb/host/ohci-sa1111.c
@@ -231,7 +231,6 @@
*/
.hub_status_data = ohci_hub_status_data,
.hub_control = ohci_hub_control,
- .hub_irq_enable = ohci_rhsc_enable,
#ifdef CONFIG_PM
.bus_suspend = ohci_bus_suspend,
.bus_resume = ohci_bus_resume,
diff --git a/drivers/usb/host/ohci-sh.c b/drivers/usb/host/ohci-sh.c
index e7ee607..60f03cc 100644
--- a/drivers/usb/host/ohci-sh.c
+++ b/drivers/usb/host/ohci-sh.c
@@ -68,7 +68,6 @@
*/
.hub_status_data = ohci_hub_status_data,
.hub_control = ohci_hub_control,
- .hub_irq_enable = ohci_rhsc_enable,
#ifdef CONFIG_PM
.bus_suspend = ohci_bus_suspend,
.bus_resume = ohci_bus_resume,
diff --git a/drivers/usb/host/ohci-sm501.c b/drivers/usb/host/ohci-sm501.c
index 21b164e..cff2363 100644
--- a/drivers/usb/host/ohci-sm501.c
+++ b/drivers/usb/host/ohci-sm501.c
@@ -75,7 +75,6 @@
*/
.hub_status_data = ohci_hub_status_data,
.hub_control = ohci_hub_control,
- .hub_irq_enable = ohci_rhsc_enable,
#ifdef CONFIG_PM
.bus_suspend = ohci_bus_suspend,
.bus_resume = ohci_bus_resume,
diff --git a/drivers/usb/host/ohci-ssb.c b/drivers/usb/host/ohci-ssb.c
index 3660c83..23fd6a8 100644
--- a/drivers/usb/host/ohci-ssb.c
+++ b/drivers/usb/host/ohci-ssb.c
@@ -81,7 +81,6 @@
.hub_status_data = ohci_hub_status_data,
.hub_control = ohci_hub_control,
- .hub_irq_enable = ohci_rhsc_enable,
#ifdef CONFIG_PM
.bus_suspend = ohci_bus_suspend,
.bus_resume = ohci_bus_resume,
diff --git a/drivers/usb/host/u132-hcd.c b/drivers/usb/host/u132-hcd.c
index 20ad3c4..228f2b0 100644
--- a/drivers/usb/host/u132-hcd.c
+++ b/drivers/usb/host/u132-hcd.c
@@ -2934,16 +2934,6 @@
return 0;
}
-static void u132_hub_irq_enable(struct usb_hcd *hcd)
-{
- struct u132 *u132 = hcd_to_u132(hcd);
- if (u132->going > 1) {
- dev_err(&u132->platform_dev->dev, "device has been removed %d\n"
- , u132->going);
- } else if (u132->going > 0)
- dev_err(&u132->platform_dev->dev, "device is being removed\n");
-}
-
#ifdef CONFIG_PM
static int u132_bus_suspend(struct usb_hcd *hcd)
@@ -2995,7 +2985,6 @@
.bus_suspend = u132_bus_suspend,
.bus_resume = u132_bus_resume,
.start_port_reset = u132_start_port_reset,
- .hub_irq_enable = u132_hub_irq_enable,
};
/*