[PATCH] root hub updates (greater half)
This patch associates hub suspend and resume logic (including for root hubs)
with CONFIG_PM -- instead of CONFIG_USB_SUSPEND as before -- thereby unifying
two troublesome versions of suspend logic into just one. It'll be easier to
keep things right from now on.
- Now usbcore _always_ calls hcd->hub_suspend as needed, instead of
only when USB_SUSPEND is enabled:
* Those root hub methods are now called from hub suspend/resume;
no more skipping between layers during device suspend/resume;
* It now handles cases allowed by sysfs or autosuspended root hubs,
by forcing the hub interface to resume too.
- All devices, including virtual root hubs, now get the same treatment
on their resume paths ... including re-activating all their interfaces.
Plus it gets rid of those stub copies of usb_{suspend,resume}_device(), and
updates the Kconfig to match the new definition of USB_SUSPEND: it provides
(a) selective suspend, downstream from hubs; and (b) remote wakeup, upstream
from any device configuration which supports it.
This calls for minor followup patches for most HCDs (and their PCI glue).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/usb/core/Kconfig | 11 ++-
drivers/usb/core/hub.c | 163 +++++++++++++++++++++++++----------------------
2 files changed, 97 insertions(+), 77 deletions(-)
diff --git a/drivers/usb/core/Kconfig b/drivers/usb/core/Kconfig
index 1a9ff61..ff03184 100644
--- a/drivers/usb/core/Kconfig
+++ b/drivers/usb/core/Kconfig
@@ -61,14 +61,17 @@
If you are unsure about this, say N here.
config USB_SUSPEND
- bool "USB suspend/resume (EXPERIMENTAL)"
+ bool "USB selective suspend/resume and wakeup (EXPERIMENTAL)"
depends on USB && PM && EXPERIMENTAL
help
If you say Y here, you can use driver calls or the sysfs
"power/state" file to suspend or resume individual USB
- peripherals. There are many related features, such as
- remote wakeup and driver-specific suspend processing, that
- may not yet work as expected.
+ peripherals.
+
+ Also, USB "remote wakeup" signaling is supported, whereby some
+ USB devices (like keyboards and network adapters) can wake up
+ their parent hub. That wakeup cascades up the USB tree, and
+ could wake the system from states like suspend-to-RAM.
If you are unsure about this, say N here.
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 3c8d8d1..6a601a4 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1612,7 +1612,7 @@
*/
static int __usb_suspend_device (struct usb_device *udev, int port1)
{
- int status;
+ int status = 0;
/* caller owns the udev device lock */
if (port1 < 0)
@@ -1638,21 +1638,10 @@
}
}
- /* "global suspend" of the HC-to-USB interface (root hub), or
- * "selective suspend" of just one hub-device link.
+ /* we only change a device's upstream USB link.
+ * root hubs have no upstream USB link.
*/
- if (!udev->parent) {
- struct usb_bus *bus = udev->bus;
- if (bus && bus->op->hub_suspend) {
- status = bus->op->hub_suspend (bus);
- if (status == 0) {
- dev_dbg(&udev->dev, "usb suspend\n");
- usb_set_device_state(udev,
- USB_STATE_SUSPENDED);
- }
- } else
- status = -EOPNOTSUPP;
- } else
+ if (udev->parent)
status = hub_port_suspend(hdev_to_hub(udev->parent), port1,
udev);
@@ -1661,6 +1650,8 @@
return status;
}
+#endif
+
/**
* usb_suspend_device - suspend a usb device
* @udev: device that's no longer in active use
@@ -1683,6 +1674,7 @@
*/
int usb_suspend_device(struct usb_device *udev)
{
+#ifdef CONFIG_USB_SUSPEND
int port1, status;
port1 = locktree(udev);
@@ -1692,8 +1684,14 @@
status = __usb_suspend_device(udev, port1);
usb_unlock_device(udev);
return status;
+#else
+ /* NOTE: udev->state unchanged, it's not lying ... */
+ udev->dev.power.power_state = PMSG_SUSPEND;
+ return 0;
+#endif
}
+
/*
* If the USB "suspend" state is in use (rather than "global suspend"),
* many devices will be individually taken out of suspend state using
@@ -1702,13 +1700,13 @@
* resume (by host) or remote wakeup (by device) ... now see what changed
* in the tree that's rooted at this device.
*/
-static int finish_port_resume(struct usb_device *udev)
+static int finish_device_resume(struct usb_device *udev)
{
int status;
u16 devstatus;
/* caller owns the udev device lock */
- dev_dbg(&udev->dev, "usb resume\n");
+ dev_dbg(&udev->dev, "finish resume\n");
/* usb ch9 identifies four variants of SUSPENDED, based on what
* state the device resumes to. Linux currently won't see the
@@ -1718,7 +1716,6 @@
usb_set_device_state(udev, udev->actconfig
? USB_STATE_CONFIGURED
: USB_STATE_ADDRESS);
- udev->dev.power.power_state = PMSG_ON;
/* 10.5.4.5 says be sure devices in the tree are still there.
* For now let's assume the device didn't go crazy on resume,
@@ -1734,7 +1731,8 @@
int (*resume)(struct device *);
le16_to_cpus(&devstatus);
- if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)) {
+ if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)
+ && udev->parent) {
status = usb_control_msg(udev,
usb_sndctrlpipe(udev, 0),
USB_REQ_CLEAR_FEATURE,
@@ -1764,6 +1762,8 @@
return status;
}
+#ifdef CONFIG_USB_SUSPEND
+
static int
hub_port_resume(struct usb_hub *hub, int port1, struct usb_device *udev)
{
@@ -1809,7 +1809,7 @@
/* TRSMRCY = 10 msec */
msleep(10);
if (udev)
- status = finish_port_resume(udev);
+ status = finish_device_resume(udev);
}
}
if (status < 0)
@@ -1818,7 +1818,7 @@
return status;
}
-static int hub_resume (struct usb_interface *intf);
+#endif
/**
* usb_resume_device - re-activate a suspended usb device
@@ -1841,35 +1841,22 @@
if (port1 < 0)
return port1;
- /* "global resume" of the HC-to-USB interface (root hub), or
- * selective resume of one hub-to-device port
- */
- if (!udev->parent) {
- struct usb_bus *bus = udev->bus;
- if (bus && bus->op->hub_resume) {
- status = bus->op->hub_resume (bus);
+#ifdef CONFIG_USB_SUSPEND
+ /* selective resume of one downstream hub-to-device port */
+ if (udev->parent) {
+ if (udev->state == USB_STATE_SUSPENDED) {
+ // NOTE swsusp may bork us, device state being wrong...
+ // NOTE this fails if parent is also suspended...
+ status = hub_port_resume(hdev_to_hub(udev->parent),
+ port1, udev);
} else
- status = -EOPNOTSUPP;
- if (status == 0) {
- dev_dbg(&udev->dev, "usb resume\n");
- /* TRSMRCY = 10 msec */
- msleep(10);
- usb_set_device_state (udev, USB_STATE_CONFIGURED);
- udev->dev.power.power_state = PMSG_ON;
- status = hub_resume (udev
- ->actconfig->interface[0]);
- }
- } else if (udev->state == USB_STATE_SUSPENDED) {
- // NOTE this fails if parent is also suspended...
- status = hub_port_resume(hdev_to_hub(udev->parent),
- port1, udev);
- } else {
- status = 0;
- }
- if (status < 0) {
+ status = 0;
+ } else
+#endif
+ status = finish_device_resume(udev);
+ if (status < 0)
dev_dbg(&udev->dev, "can't resume, status %d\n",
status);
- }
usb_unlock_device(udev);
@@ -1886,6 +1873,8 @@
{
int status = 0;
+#ifdef CONFIG_USB_SUSPEND
+
/* don't repeat RESUME sequence if this device
* was already woken up by some other task
*/
@@ -1894,9 +1883,10 @@
dev_dbg(&udev->dev, "RESUME (wakeup)\n");
/* TRSMRCY = 10 msec */
msleep(10);
- status = finish_port_resume(udev);
+ status = finish_device_resume(udev);
}
up(&udev->serialize);
+#endif
return status;
}
@@ -1911,12 +1901,32 @@
struct usb_device *udev;
udev = hdev->children [port1-1];
- if (udev && udev->state != USB_STATE_SUSPENDED) {
+ if (udev && (udev->dev.power.power_state.event
+ == PM_EVENT_ON
+#ifdef CONFIG_USB_SUSPEND
+ || udev->state != USB_STATE_SUSPENDED
+#endif
+ )) {
dev_dbg(&intf->dev, "port %d nyet suspended\n", port1);
return -EBUSY;
}
}
+ /* "global suspend" of the downstream HC-to-USB interface */
+ if (!hdev->parent) {
+ struct usb_bus *bus = hdev->bus;
+ if (bus && bus->op->hub_suspend) {
+ int status = bus->op->hub_suspend (bus);
+
+ if (status != 0) {
+ dev_dbg(&hdev->dev, "'global' suspend %d\n",
+ status);
+ return status;
+ }
+ } else
+ return -EOPNOTSUPP;
+ }
+
/* stop khubd and related activity */
hub_quiesce(hub);
return 0;
@@ -1926,9 +1936,36 @@
{
struct usb_device *hdev = interface_to_usbdev(intf);
struct usb_hub *hub = usb_get_intfdata (intf);
- unsigned port1;
int status;
+ /* "global resume" of the downstream HC-to-USB interface */
+ if (!hdev->parent) {
+ struct usb_bus *bus = hdev->bus;
+ if (bus && bus->op->hub_resume) {
+ status = bus->op->hub_resume (bus);
+ if (status) {
+ dev_dbg(&intf->dev, "'global' resume %d\n",
+ status);
+ return status;
+ }
+ } else
+ return -EOPNOTSUPP;
+ if (status == 0) {
+ /* TRSMRCY = 10 msec */
+ msleep(10);
+ }
+ }
+
+ hub_activate(hub);
+
+ /* REVISIT: this recursion probably shouldn't exist. Remove
+ * this code sometime, after retesting with different root and
+ * external hubs.
+ */
+#ifdef CONFIG_USB_SUSPEND
+ {
+ unsigned port1;
+
for (port1 = 1; port1 <= hdev->maxchild; port1++) {
struct usb_device *udev;
u16 portstat, portchange;
@@ -1953,7 +1990,7 @@
if (portstat & USB_PORT_STAT_SUSPEND)
status = hub_port_resume(hub, port1, udev);
else {
- status = finish_port_resume(udev);
+ status = finish_device_resume(udev);
if (status < 0) {
dev_dbg(&intf->dev, "resume port %d --> %d\n",
port1, status);
@@ -1962,8 +1999,8 @@
}
up(&udev->serialize);
}
- hub->resume_root_hub = 0;
- hub_activate(hub);
+ }
+#endif
return 0;
}
@@ -1987,26 +2024,6 @@
kick_khubd(hub);
}
-#else /* !CONFIG_USB_SUSPEND */
-
-int usb_suspend_device(struct usb_device *udev)
-{
- /* state does NOT lie by saying it's USB_STATE_SUSPENDED! */
- return 0;
-}
-
-int usb_resume_device(struct usb_device *udev)
-{
- udev->dev.power.power_state.event = PM_EVENT_ON;
- return 0;
-}
-
-#define hub_suspend NULL
-#define hub_resume NULL
-#define remote_wakeup(x) 0
-
-#endif /* CONFIG_USB_SUSPEND */
-
EXPORT_SYMBOL(usb_suspend_device);
EXPORT_SYMBOL(usb_resume_device);