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 (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 revised patch (as715b) renames usb_suspend_device to
usb_port_suspend, usb_resume_device to usb_port_resume, and
finish_device_resume to finish_port_resume.  There was no objection to
the original version of the patch so this should be okay to apply.

The revision was needed only because I have re-arranged the order of the
earlier patches.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as731) makes a couple of small fixes to the hub_port_resume
routine:

	Don't return status >= 0 when an error occurs;

	Clear the port-change-suspend status indicator after
	resuming a device.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

finish_device_resume() in the hub driver isn't careful always to return
a negative code in all the error pathways.  It also doesn't return 0 in
all the success pathways.  This patch (as724) fixes the behavior.
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>

This patch (as700) modifies the hub driver to take advantage of the new
usb_reset_composite_device API.  The existing code had special-case
calls stuck into usb_reset_device, just before and after the reset.
With the new version there's no need for special-case stuff; it all
happens naturally in the form of pre_reset and post_reset notifications.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as699) adds usb_reset_composite_device(), a routine for
sending a USB port reset to a device with multiple interfaces owned by
different drivers.  Drivers are notified about impending and completed
resets through two new methods in the usb_driver structure.

The patch modifieds the usbfs ioctl code to make it use the new routine
instead of usb_reset_device().  Follow-up patches will modify the hub,
usb-storage, and usbhid drivers so they can utilize this new API.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

RNDIS devices don't get configured owing to a typo in
choose_configuration().  This patch from Giridhar Pemmasani fixes the
typo.

From: Giridhar Pemmasani <giri@lmc.cs.sunysb.edu>
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

2.6.16 introduces USB power budgeting in the Linux kernel, and since then, a
fair number of users have observed that some of their devices no longer work in
unpowered hubs (this is not a bug, the devices claim that they need more than
100mA).

The very least we can do is print an informational message to the kernel log
when this happens, otherwise it is not at all clear why the device was not
accepted.
Signed-off-by: NDaniel Drake <dsd@gentoo.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Some hubs claim not to support port-power switching, and right now the
hub driver believes them and does not enable power to their ports.
However it turns out that even though they don't actually switch power,
they do ignore all events on a port until told to turn on the power!
This problem has been reported by several users.

This revised patch (as672b) makes the hub driver always try to turn on
port power to all hubs, regardless of what the hub descriptor says.  It
also adds a comment explaining the need for this.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The choose_configuration() routine contains code the determine the
device's power source, so that configurations requiring external power
can be ruled out if the device is running on bus power.  Unfortunately
it turns out that some devices have errors in their config descriptors
and other devices don't like the GET_DEVICE_STATUS request.

Since that information wasn't used for anything else, this patch (as673)
removes the code, leaving only a comment.  It fixes bugzilla entry
#6448.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

USB OTG devices are not required to support external hubs.  This adds a
configuration option to disable that support.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch removes the following unused EXPORT_SYMBOL's:
- hub.c: usb_set_device_state
- usb.c: usb_alloc_dev
- usb.c: usb_disconnect
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

In a couple of places, usbcore assumes that a USB device configuration
will have a nonzero number of interfaces.  Having no interfaces may or
may not be allowed by the USB spec; in any event we shouldn't die if we
encounter such a thing.  This patch (as662) removes the assumptions.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as647) fixes a small error introduced by a recent change to
the USB core suspend/resume code.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This makes usbcore use the driver model wakeup flags for host controllers
and for their root hubs.  Since previous patches have removed all users of
the HCD flags they replace, this converts the last users of those flags.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

the patch below converts a bunch of semaphores-used-as-mutex in the USB
code to mutexes
Signed-off-by: NArjan van de Ven <arjan@infradead.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as614) makes a small change to the part of the hub driver
responsible for remote wakeup of root hubs.  When these wakeups occur
the driver is suspended, and in case the resume fails the driver should
remain suspended -- it shouldn't try to proceed with its normal
processing.

This will hardly ever matter in normal use, but it did crop up while I
was debugging a different problem.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as610) adds a field to struct usb_device to store the device's
port number.  This allows us to remove several loops in the hub driver
(searching for a particular device among all the entries in the parent's
array of children).
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as609) changes the way we keep track of power budgeting for
USB hubs and devices, and it updates the choose_configuration routine to
take this information into account.  (This is something we should have
been doing all along.)  A new field in struct usb_device holds the amount
of bus current available from the upstream port, and the usb_hub structure
keeps track of the current available for each downstream port.

Two new rules for configuration selection are added:

	Don't select a self-powered configuration when only bus power
	is available.

	Don't select a configuration requiring more bus power than is
	available.

However the first rule is #if-ed out, because I found that the internal
hub in my HP USB keyboard claims that its only configuration is
self-powered.  The rule would prevent the configuration from being chosen,
leaving the hub & keyboard unconfigured.  Since similar descriptor errors
may turn out to be fairly common, it seemed wise not to include a rule
that would break automatic configuration unnecessarily for such devices.

The second rule may also trigger unnecessarily, although this should be
less common.  More likely it will annoy people by sometimes failing to
accept configurations that should never have been chosen in the first
place.

The patch also changes usbcore's reaction when no configuration is
suitable.  Instead of raising an error and rejecting the device, now
the core will simply leave the device unconfigured.  People can always
work around such problems by installing configurations manually through
sysfs.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The earlier USB locking updates didn't touch the suspend/resume
routines.  They need updating as well, since now the caller holds the
device semaphore.  This patch (as608) makes the necessary changes.  It
also adds a line to store the correct power state when a device is
resumed, something which was unaccountably missing.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as606b) is an updated version of my earlier patch to
disconnect children from a hub device when the hub driver is unbound.
Thanks to the changes in the driver core locking, we now know that the
entire hub device (and not just the interface) is locked whenever the
hub driver's disconnect method runs.  Hence it is safe to disconnect the
child device structures immediately instead of deferring the job.

The earlier version of the patch neglected to disable the hub's ports.
We don't want to forget that; otherwise we'd end up with live devices
using addresses that have been recycled.  This update adds the necessary
code.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

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>

It is no longer needed, so let's remove it, saving a bit of memory.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as515b) adds a routine to usbcore to simplify handling of
host controllers that lost power or were reset during suspend/resume.
The new core routine marks all the child devices of the root hub as
NOTATTACHED and tells khubd to disconnect the device structures as soon
as possible.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This fixes some bugs in EHCI suspend/resume that joined us over the past
few releases (as usbcore, PCI, pmcore, and other components evolved):

  - Removes suspend and resume recursion from the EHCI driver, getting
    rid of the USB_SUSPEND special casing.

  - Updates the wakeup mechanism to work again; there's a newish usbcore
    call it needs to use.

  - Provide simpler tests for "do we need to restart from scratch", to
    address another case where PCI Vaux was lost.  (In this case it was
    restoring a swsusp snapshot, but there could be others.)

Un-exports a symbol that was temporarily exported.

A notable change from previous version is that this doesn't move
the spinlock init, so there's still a resume/reinit path bug.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This lets us remove a lot of code in the drivers that were all checking
the same thing.  It also found some bugs in a few of the drivers, which
has been fixed up.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Thanks to Andrew for doing the hard work on this.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

With CONFIG_PM=n:

drivers/built-in.o(.text+0x1098c): In function `hub_thread':
drivers/usb/core/hub.c:2673: undefined reference to `.dpm_runtime_resume'
drivers/built-in.o(.text+0x10998):drivers/usb/core/hub.c:2674: undefined reference to `.dpm_runtime_resume'

Please, never ever ever put extern decls into .c files.  Use the darn header
files :(

Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as592) makes a few small improvements to the way device
strings are handled, and it fixes some bugs in a couple of other sysfs
attribute routines.  (Look at show_configuration_string() to see what I
mean.)
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as590) fixes up all the remaining places where usbcore can
use kzalloc rather than kmalloc/memset.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

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

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

This should let us get rid of all of the different hooks in the USB core for
when something has changed.

Also, some other parts of the kernel have wanted to know this kind of
information at times.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as580) is perhaps the only result from the long discussion I
had with David about his changes to the root-hub suspend/resume code.  It
renames the hub_suspend and hub_resume methods in struct usb_hcd to
bus_suspend and bus_resume.  These are more descriptive names, since the
methods really do suspend or resume an entire USB bus, and less likely to
be confused with the hub_suspend and hub_resume routines in hub.c.

It also takes David's advice about removing the layer of bus glue, where
those methods are called.  And it implements a related change that David
made to the other HCDs but forgot to put into dummy_hcd.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Also has the nice benefit of making sparc alignment issues go away.

Thanks to David Miller for pointing out the problems here.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

 drivers/usb/core/hub.c |   22 ++++++++++++----------
 drivers/usb/core/hub.h |    2 +-
 2 files changed, 13 insertions(+), 11 deletions(-)

The way we're looking at USB suspend lately doesn't expect drivers to
call usb_suspend_device() or usb_resume_device() directly; that'll
be implicit when no interfaces are in use.

This patch removes those APIs from visibility outside usbcore.
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>

 drivers/usb/core/hub.c |   12 ++++--------
 drivers/usb/core/usb.h |    4 ++++
 include/linux/usb.h    |    5 -----
 3 files changed, 8 insertions(+), 13 deletions(-)

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: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

 drivers/usb/core/Kconfig |   11 ++-
 drivers/usb/core/hub.c   |  163 +++++++++++++++++++++++++----------------------
 2 files changed, 97 insertions(+), 77 deletions(-)