[PATCH] usb_interface power state
This updates the handling of power state for USB interfaces.
- Formalizes an existing invariant: interface "power state" is a boolean:
ON when I/O is allowed, and FREEZE otherwise. It does so by defining
some inlined helpers, then using them.
- Adds a useful invariant: the only interfaces marked active are those
bound to non-suspended drivers. Later patches build on this invariant.
- Simplifies the interface driver API (and removes some error paths) by
removing the requirement that they record power state changes during
suspend and resume callbacks. Now usbcore does that.
A few drivers were simplified to address that last change.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/usb/core/hub.c | 33 +++++++++------------
drivers/usb/core/message.c | 1
drivers/usb/core/usb.c | 65 +++++++++++++++++++++++++++++++++----------
drivers/usb/core/usb.h | 18 +++++++++++
drivers/usb/input/hid-core.c | 2 -
drivers/usb/misc/usbtest.c | 10 ------
drivers/usb/net/pegasus.c | 2 -
drivers/usb/net/usbnet.c | 2 -
8 files changed, 85 insertions(+), 48 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index c3e2024..61341d2 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -1624,7 +1624,7 @@
struct usb_driver *driver;
intf = udev->actconfig->interface[i];
- if (state.event <= intf->dev.power.power_state.event)
+ if (!is_active(intf))
continue;
if (!intf->dev.driver)
continue;
@@ -1632,11 +1632,12 @@
if (driver->suspend) {
status = driver->suspend(intf, state);
- if (intf->dev.power.power_state.event != state.event
- || status)
+ if (status == 0)
+ mark_quiesced(intf);
+ else
dev_err(&intf->dev,
- "suspend %d fail, code %d\n",
- state.event, status);
+ "suspend error %d\n",
+ status);
}
/* only drivers with suspend() can ever resume();
@@ -1787,7 +1788,7 @@
struct usb_driver *driver;
intf = udev->actconfig->interface[i];
- if (intf->dev.power.power_state.event == PM_EVENT_ON)
+ if (is_active(intf))
continue;
if (!intf->dev.driver) {
/* FIXME maybe force to alt 0 */
@@ -1800,12 +1801,14 @@
continue;
/* can we do better than just logging errors? */
+ mark_active(intf);
status = driver->resume(intf);
- if (intf->dev.power.power_state.event != PM_EVENT_ON
- || status)
+ if (status < 0) {
+ mark_quiesced(intf);
dev_dbg(&intf->dev,
- "resume fail, state %d code %d\n",
- intf->dev.power.power_state.event, status);
+ "resume error %d\n",
+ status);
+ }
}
status = 0;
@@ -1952,7 +1955,7 @@
return status;
}
-static int hub_suspend(struct usb_interface *intf, pm_message_t state)
+static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
{
struct usb_hub *hub = usb_get_intfdata (intf);
struct usb_device *hdev = hub->hdev;
@@ -1970,14 +1973,13 @@
if (!udev)
continue;
down(&udev->serialize);
- status = __usb_suspend_device(udev, port1, state);
+ status = __usb_suspend_device(udev, port1, msg);
up(&udev->serialize);
if (status < 0)
dev_dbg(&intf->dev, "suspend port %d --> %d\n",
port1, status);
}
- intf->dev.power.power_state = state;
return 0;
}
@@ -1988,9 +1990,6 @@
unsigned port1;
int status;
- if (intf->dev.power.power_state.event == PM_EVENT_ON)
- return 0;
-
for (port1 = 1; port1 <= hdev->maxchild; port1++) {
struct usb_device *udev;
u16 portstat, portchange;
@@ -2024,8 +2023,6 @@
}
up(&udev->serialize);
}
- intf->dev.power.power_state = PMSG_ON;
-
hub->resume_root_hub = 0;
hub_activate(hub);
return 0;
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index f9a81e8..ebf59ea 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1393,6 +1393,7 @@
intf->dev.dma_mask = dev->dev.dma_mask;
intf->dev.release = release_interface;
device_initialize (&intf->dev);
+ mark_quiesced(intf);
sprintf (&intf->dev.bus_id[0], "%d-%s:%d.%d",
dev->bus->busnum, dev->devpath,
configuration,
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 4c57f3f..6ecfdce 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -107,10 +107,19 @@
id = usb_match_id (intf, driver->id_table);
if (id) {
dev_dbg (dev, "%s - got id\n", __FUNCTION__);
+
+ /* Interface "power state" doesn't correspond to any hardware
+ * state whatsoever. We use it to record when it's bound to
+ * a driver that may start I/0: it's not frozen/quiesced.
+ */
+ mark_active(intf);
intf->condition = USB_INTERFACE_BINDING;
error = driver->probe (intf, id);
- intf->condition = error ? USB_INTERFACE_UNBOUND :
- USB_INTERFACE_BOUND;
+ if (error) {
+ mark_quiesced(intf);
+ intf->condition = USB_INTERFACE_UNBOUND;
+ } else
+ intf->condition = USB_INTERFACE_BOUND;
}
return error;
@@ -136,6 +145,7 @@
0);
usb_set_intfdata(intf, NULL);
intf->condition = USB_INTERFACE_UNBOUND;
+ mark_quiesced(intf);
return 0;
}
@@ -299,6 +309,7 @@
dev->driver = &driver->driver;
usb_set_intfdata(iface, priv);
iface->condition = USB_INTERFACE_BOUND;
+ mark_active(iface);
/* if interface was already added, bind now; else let
* the future device_add() bind it, bypassing probe()
@@ -345,6 +356,7 @@
dev->driver = NULL;
usb_set_intfdata(iface, NULL);
iface->condition = USB_INTERFACE_UNBOUND;
+ mark_quiesced(iface);
}
/**
@@ -1404,8 +1416,9 @@
static int usb_generic_suspend(struct device *dev, pm_message_t message)
{
- struct usb_interface *intf;
- struct usb_driver *driver;
+ struct usb_interface *intf;
+ struct usb_driver *driver;
+ int status;
if (dev->driver == &usb_generic_driver)
return usb_suspend_device (to_usb_device(dev), message);
@@ -1417,21 +1430,34 @@
intf = to_usb_interface(dev);
driver = to_usb_driver(dev->driver);
- /* there's only one USB suspend state */
- if (intf->dev.power.power_state.event)
+ /* with no hardware, USB interfaces only use FREEZE and ON states */
+ if (!is_active(intf))
return 0;
- if (driver->suspend)
- return driver->suspend(intf, message);
- return 0;
+ if (driver->suspend && driver->resume) {
+ status = driver->suspend(intf, message);
+ if (status)
+ dev_err(dev, "%s error %d\n", "suspend", status);
+ else
+ mark_quiesced(intf);
+ } else {
+ // FIXME else if there's no suspend method, disconnect...
+ dev_warn(dev, "no %s?\n", "suspend");
+ status = 0;
+ }
+ return status;
}
static int usb_generic_resume(struct device *dev)
{
- struct usb_interface *intf;
- struct usb_driver *driver;
+ struct usb_interface *intf;
+ struct usb_driver *driver;
+ int status;
- /* devices resume through their hub */
+ if (dev->power.power_state.event == PM_EVENT_ON)
+ return 0;
+
+ /* devices resume through their hubs */
if (dev->driver == &usb_generic_driver)
return usb_resume_device (to_usb_device(dev));
@@ -1442,8 +1468,19 @@
intf = to_usb_interface(dev);
driver = to_usb_driver(dev->driver);
- if (driver->resume)
- return driver->resume(intf);
+ /* if driver was suspended, it has a resume method;
+ * however, sysfs can wrongly mark things as suspended
+ * (on the "no suspend method" FIXME path above)
+ */
+ mark_active(intf);
+ if (driver->resume) {
+ status = driver->resume(intf);
+ if (status) {
+ dev_err(dev, "%s error %d\n", "resume", status);
+ mark_quiesced(intf);
+ }
+ } else
+ dev_warn(dev, "no %s?\n", "resume");
return 0;
}
diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h
index e6504f3..3741a99 100644
--- a/drivers/usb/core/usb.h
+++ b/drivers/usb/core/usb.h
@@ -28,6 +28,24 @@
extern int usb_host_init(void);
extern void usb_host_cleanup(void);
+/* Interfaces and their "power state" are owned by usbcore */
+
+static inline void mark_active(struct usb_interface *f)
+{
+ f->dev.power.power_state.event = PM_EVENT_ON;
+}
+
+static inline void mark_quiesced(struct usb_interface *f)
+{
+ f->dev.power.power_state.event = PM_EVENT_FREEZE;
+}
+
+static inline int is_active(struct usb_interface *f)
+{
+ return f->dev.power.power_state.event == PM_EVENT_ON;
+}
+
+
/* for labeling diagnostics */
extern const char *usbcore_name;
diff --git a/drivers/usb/input/hid-core.c b/drivers/usb/input/hid-core.c
index 411a064..f7fcce7 100644
--- a/drivers/usb/input/hid-core.c
+++ b/drivers/usb/input/hid-core.c
@@ -1887,7 +1887,6 @@
struct hid_device *hid = usb_get_intfdata (intf);
usb_kill_urb(hid->urbin);
- intf->dev.power.power_state = PMSG_SUSPEND;
dev_dbg(&intf->dev, "suspend\n");
return 0;
}
@@ -1897,7 +1896,6 @@
struct hid_device *hid = usb_get_intfdata (intf);
int status;
- intf->dev.power.power_state = PMSG_ON;
if (hid->open)
status = usb_submit_urb(hid->urbin, GFP_NOIO);
else
diff --git a/drivers/usb/misc/usbtest.c b/drivers/usb/misc/usbtest.c
index 54799eb..d055196 100644
--- a/drivers/usb/misc/usbtest.c
+++ b/drivers/usb/misc/usbtest.c
@@ -1948,21 +1948,11 @@
static int usbtest_suspend (struct usb_interface *intf, pm_message_t message)
{
- struct usbtest_dev *dev = usb_get_intfdata (intf);
-
- down (&dev->sem);
- intf->dev.power.power_state = PMSG_SUSPEND;
- up (&dev->sem);
return 0;
}
static int usbtest_resume (struct usb_interface *intf)
{
- struct usbtest_dev *dev = usb_get_intfdata (intf);
-
- down (&dev->sem);
- intf->dev.power.power_state = PMSG_ON;
- up (&dev->sem);
return 0;
}
diff --git a/drivers/usb/net/pegasus.c b/drivers/usb/net/pegasus.c
index 6a4ffe6..537eb18 100644
--- a/drivers/usb/net/pegasus.c
+++ b/drivers/usb/net/pegasus.c
@@ -1384,7 +1384,6 @@
usb_kill_urb(pegasus->rx_urb);
usb_kill_urb(pegasus->intr_urb);
}
- intf->dev.power.power_state = PMSG_SUSPEND;
return 0;
}
@@ -1392,7 +1391,6 @@
{
struct pegasus *pegasus = usb_get_intfdata(intf);
- intf->dev.power.power_state = PMSG_ON;
netif_device_attach (pegasus->net);
if (netif_running(pegasus->net)) {
pegasus->rx_urb->status = 0;
diff --git a/drivers/usb/net/usbnet.c b/drivers/usb/net/usbnet.c
index fce81d7..74f05c9 100644
--- a/drivers/usb/net/usbnet.c
+++ b/drivers/usb/net/usbnet.c
@@ -1185,7 +1185,6 @@
netif_device_detach (dev->net);
(void) unlink_urbs (dev, &dev->rxq);
(void) unlink_urbs (dev, &dev->txq);
- intf->dev.power.power_state = PMSG_SUSPEND;
return 0;
}
EXPORT_SYMBOL_GPL(usbnet_suspend);
@@ -1194,7 +1193,6 @@
{
struct usbnet *dev = usb_get_intfdata(intf);
- intf->dev.power.power_state = PMSG_ON;
netif_device_attach (dev->net);
tasklet_schedule (&dev->bh);
return 0;