This patch (as787) creates a new workqueue thread to handle delayed
USB autosuspend requests.  Previously the code used keventd.  However
it turns out that the hub driver's suspend routine calls
flush_scheduled_work(), making it a poor candidate for running in
keventd (the call immediately deadlocks).  The solution is to use a
new thread instead of keventd.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Fixes kerneldoc errors on usb/core/driver.c, which occured in 2.6.18-rc6-mm2
gregkh-usb-usbcore-add-autosuspend-autoresume-infrastructure.patch
Signed-off-by: NHenrik Kretzschmar <henne@nachtwindheim.de>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as786) removes a redundant test and fixes a problem
involving repeated system sleeps when CONFIG_USB_SUSPEND is not set.
During the first wakeup, the root hub's dev.power.power_state.event
field doesn't get updated, causing it not to be suspended during the
second sleep transition.

This takes care of the issue raised by Rafael J. Wysocki and Mattia
Dongili.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as739) adds the basic infrastructure for USB autosuspend
and autoresume.  The main features are:

	PM usage counters added to struct usb_device and struct
	usb_interface, indicating whether it's okay to autosuspend
	them or they are currently in use.

	Flag added to usb_device indicating whether the current
	suspend/resume operation originated from outside or as an
	autosuspend/autoresume.

	Flag added to usb_driver indicating whether the driver
	supports autosuspend.  If not, no device bound to the driver
	will be autosuspended.

	Mutex added to usb_device for protecting PM operations.
	Unlike the device semaphore, the locking rule for the pm_mutex
	is that you must acquire the locks going _up_ the device tree.

	New routines handling autosuspend/autoresume requests for
	interfaces and devices.

	Suspend and resume requests are propagated up the device tree
	(but not outside the USB subsystem).

	work_struct added to usb_device, for carrying out delayed
	autosuspend requests.

	Autoresume added (and autosuspend prevented) during probe and
	disconnect.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Since usb_generic can be unbound from a USB device, we need to be able
to handle the possibility that a suspend or resume request arrives for a
device with no driver.  This patch (as735) arranges things so that
resume requests will fail and suspend requests will use the standard USB
port-suspend code.  Attempts to suspend or resume an unbound interface
are handled similarly (although the error caused by trying to resume an
unbound interface is dropped by the calling routine).
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as734) rationalizes the various tests of device state and
power states.  There are duplications and mistaken tests in several
places.

Perhaps the most interesting challenge is where the hub driver tests to
see that all the child devices are suspended before allowing itself to
be suspended.  When CONFIG_USB_SUSPEND is set the test is
straightforward, since we expect that the children _will_ be suspended.
But when CONFIG_USB_SUSPEND isn't set, it's not so clear what should be
done.  The code compromises by checking the child's
power.power_state.event field.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as733) fixes up the places where device states and power
states are set in usbcore.  Right now things are duplicated or missing;
this should straighten things out.

The idea is that udev->state is USB_STATE_SUSPENDED exactly when the
device's upstream port has been suspended, whereas
udev->dev.power.power_state.event reflects the result of the last call
to the suspend/resume routines (which might not actually change the
device state, especially if CONFIG_USB_SUSPEND isn't set).
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as717b) removes the existing recursion in hub resume code:
Resuming a hub will no longer automatically resume the devices attached
to the hub.

At the same time, it adds one level of recursion: Suspending a USB
device will automatically suspend all the device's interfaces.  Failure
at an intermediate stage will cause all the already-suspended interfaces
to be resumed. Attempts to suspend or resume an interface by itself will
do nothing, although they won't return an error.  Thus the regular
system-suspend and system-resume procedures should continue to work as
before; only runtime PM will be affected.

The patch also removes the code that tests state of the interfaces
before suspending a device.  It's no longer needed, since everything
gets suspended together.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as716b) splits up the core suspend and resume routines into
two parts each: one for handling devices and one for handling
interfaces.  The behavior of the parts should be the same as in the old
unified code.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as714b) makes usb_generic into a usb_device_driver capable
of being probed and unbound, just like other drivers.  A fair amount of
the work that used to get done during discovery or removal of a USB
device have been moved to the probe and disconnect methods of
usb_generic: creating the sysfs attributes and selecting an initial
configuration.  However the normal behavior should continue to be the
same as before.

We will now have the possibility of creating other USB device drivers,
They will assist with exporting devices to remote systems
(USB-over-TCPIP) or to paravirtual guest operating systems.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as732) adds a usb_device_driver structure, for representing
drivers that manage an entire USB device as opposed to just an
interface.  Support routines like usb_register_device_driver,
usb_deregister_device_driver, usb_probe_device, and usb_unbind_device
are also added.

Unlike an earlier version of this patch, the new code is type-safe.  To
accomplish this, the existing struct driver embedded in struct
usb_driver had to be wrapped in an intermediate wrapper.  This enables
the core to tell at runtime whether a particular struct driver belongs
to a device driver or to an interface driver.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This revised patch (as713b) moves a few routines among source files in
usbcore.  Some driver-related code in usb.c (claiming interfaces and
matching IDs) is moved to driver.c, where it belongs.  Also the
usb_generic stuff in driver.c is moved to a new source file: generic.c.
(That's the reason for revising the patch.)  Although not very big now,
it will get bigger in a later patch.

None of the code has been changed; it has only been re-arranged.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

The USB core symbols will be converted to GPL-only in a few years.  Mark
this as such and update the documentation explaining why, and provide a
pointer for developers to receive help if they need it.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

I thought we had fixed up all non-gpl USB drivers, and was wrong to do
this.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch (as605) removes the private udev->serialize semaphore,
relying instead on the locking provided by the embedded struct device's
semaphore.  The changes are confined to the core, except that the
usb_trylock_device routine now uses the return convention of
down_trylock rather than down_read_trylock (they return opposite values
for no good reason).

A couple of other associated changes are included as well:

	Now that we aren't concerned about HCDs that avoid using the
	hcd glue layer, usb_disconnect no longer needs to acquire the
	usb_bus_lock -- that can be done by usb_remove_hcd where it
	belongs.

	Devices aren't locked over the same scope of code in
	usb_new_device and hub_port_connect_change as they used to be.
	This shouldn't cause any trouble.

Along with the preceding driver core patch, this needs a lot of testing.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This fixes the driver that forgot to set the module owner up.  Now we
can remove the unneeded pointer from the usb driver structure.  The idea
for how to do this was from Al Viro, who did this for the PCI drivers.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This lets drivers, like the usb-serial ones, disable the ability to add
ids from sysfs.

The usb-serial drivers are "odd" in that they are really usb-serial bus
drivers, not usb bus drivers, so the dynamic id logic will have to go
into the usb-serial bus core for those drivers to get that ability.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Echo the usb vendor and product id to the "new_id" file in the driver's
sysfs directory, and then that driver will be able to bind to a device
with those ids if it is present.

Example:
	echo 0557 2008 > /sys/bus/usb/drivers/foo_driver/new_id
adds the hex values 0557 and 2008 to the device id table for the foo_driver.

Note, usb-serial drivers do not currently work with this capability yet.
usb-storage also might have some oddities.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This will make the dynamic-id stuff easier to do, as it will be
self-contained.

No logic was changed at all.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>