This patch (as1046) makes USB-PERSIST work more in accordance with
the documentation.  Currently it takes effect only in cases where the
root hub has lost power or been reset, but it is supposed to operate
whenever a power session was dropped during a system sleep.

A new hub_restart() routine carries out the duties required during a
reset or a reset-resume.  It checks to see whether occupied ports are
still enabled, and if they aren't then it clears the enable-change and
connect-change features (to prevent interference by khubd) and sets
the child device's reset_resume flag.  It also checks ports that are
supposed to be unoccupied to verify that the firmware hasn't left the
port in an enabled state.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as1045) reorganizes some code in the hub driver.
hub_port_status() is moved earlier in the file, and a new hub_stop()
routine is created to do the work currently in hub_preset() (i.e.,
disconnect all child devices and quiesce the hub).

There are no functional changes.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as1044) causes EHCI port handover for non-high-speed
devices to occur during every root-hub resume, not just in cases where
the controller lost power or was reset.  This is necessary because:

	When some machines go into suspend, they remove power from
	on-board USB devices while retaining suspend current for USB
	controllers.

	The user might well unplug a USB device while the system is
	suspended and then plug it back in before resuming.

A corresponding change is made to the core resume routine; now
high-speed root hubs will always be resumed when the system wakes up,
even if they were suspended before the system went to sleep.  If this
weren't done then EHCI port handover wouldn't work, since it is called
when the EHCI root hub is resumed.

Finally, a comment is added to the hub driver explaining the khubd has
to be freezable; if it weren't frozen then it could interfere with
port handover.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

None of these files use any of the functionality promised by
asm/semaphore.h.  It's possible that they rely on it dragging in some
unrelated header file, but I can't build all these files, so we'll have
fix any build failures as they come up.
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>

Over two years ago, the Linux USB developers stated that they believed
there was no way to create a USB kernel driver that was not under the
GPL.  This patch moves the USB apis to enforce that decision.

There are no known closed source USB drivers in the wild, so this patch
should cause no problems.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch exports two statistics to userspace:
/sys/bus/usb/device/.../power/connected_duration
/sys/bus/usb/device/.../power/active_duration

connected_duration is the total time (in msec) that the device has
been connected.  active_duration is the total time the device has not
been suspended.  With these two statistics, tools like PowerTOP can
calculate the percentage time that a device is active, i.e. not
suspended or auto-suspended.

Users can also use the active_duration to check if a device is actually
autosuspended.  Currently, they can set power/level to auto and
power/autosuspend to a positive timeout, but there's no way to know from
userspace if a device was actually autosuspended without looking at the
dmesg output.  These statistics will be useful in creating an automated
userspace script to test autosuspend for USB devices.
Signed-off-by: NSarah Sharp <sarah.a.sharp@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as1023) updates the code in usb_reset_composite_device():

	Some local variable declarations are moved to inner loops.

	The interface locks are not acquired.  This isn't necessary
	any more; its only reason was to prevent an interface from
	being suspended or resumed during the reset.  But now
	interface power management is controlled by the USB device
	lock, not by the interface lock.

	The check for whether the interface is registered is removed.
	There doesn't seem to be any reason for checking; a driver
	for a non-registered interface deserves to be informed of
	device resets just as much as any other.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Distros (like SuSE) want to know this information, to make it easier
to handle support issues.  Might as well let everyone benefit from this.
This is also enabled whenever CONFIG_USB_DEBUG is enabled, to help with
debugging.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch hands over the port to the companion when the
hub_port_connect_change fails.
Signed-off-by: NBalaji Rao <balajirrao@gmail.com>
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

this function will run in the context of the scsi error handler thread.
It must use GFP_NOIO instead of GFP_KERNEL to avoid a possible
deadlock.

Cc: stable <stable@kernel.org>
Signed-off-by: NOliver Neukum <oneukum@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as1027) replaces a call to flush_scheduled_work() -- a
dangerous routine to invoke, especially while holding any sort of lock
-- with calls to cancel_work_sync() and cancel_delayed_work_sync().

This fixes Bugzilla #9532.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Fixes priority mistakes similar to '!x & y'
Signed-off-by: NRoel Kluin <12o3l@tiscali.nl>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Introduce freezer-friendly wrappers around wait_event_interruptible() and
wait_event_interruptible_timeout(), originally defined in <linux/wait.h>, to
be used in freezable kernel threads.  Make some of the freezable kernel
threads use them.

This is necessary for the freezer to stop sending signals to kernel threads,
which is implemented in the next patch.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NPavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix USB docbook warnings.

Warning(linux-2.6.23-git8//include/linux/usb/gadget.h:487): No description found for parameter 'g'
Warning(linux-2.6.23-git8//include/linux/usb/gadget.h:506): No description found for parameter 'g'

Warning(linux-2.6.23-git8//drivers/usb/core/hub.c:1416): No description found for parameter 'usb_dev'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch (as999) fixes a problem that sometimes shows up when host
controller driver modules are loaded in the wrong order.  If ehci-hcd
happens to initialize an EHCI controller while the companion OHCI or
UHCI controller is in the middle of a port reset, the reset can fail
and the companion may get very confused.  The patch adds an
rw-semaphore and uses it to keep EHCI initialization and port resets
mutually exclusive.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Acked-by: NDavid Brownell <david-b@pacbell.net>
Cc: David Miller <davem@davemloft.net>
Cc: Dely L Sy <dely.l.sy@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (jx001) fixes a variable assignment mistake in hub driver.
limited_power should be set to 0 if the hub is self-powered,and 1 if
the hub is bus-powered.

However, the effect of the code was exactly opposite to the spec's
statement for the Local Power Source field. The spec says, this field
is 1 meaning Local power supply lost while this field is 0 indicating
Local power supply good.(This statement is very confusing.)

So this patch switchs the 0 and 1.
Signed-off-by: NJason Xiao <jidong.xiao@gmail.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as989) makes usbcore flush all outstanding URBs for each
device as the device is suspended.  This will be true even when
CONFIG_USB_SUSPEND is not enabled.

In addition, an extra can_submit flag is added to the usb_device
structure.  That flag will be turned off whenever a suspend request
has been received for the device, even if the device isn't actually
suspended because CONFIG_USB_SUSPEND isn't set.

It's no longer necessary to check for the device state being equal to
USB_STATE_SUSPENDED during URB submission; that check can be replaced
by a check of the can_submit flag.  This also permits us to remove
some questionable references to the deprecated power.power_state field.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as981) removes the remaining nontrivial usages of
urb->status from usbcore.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

As it is global, give it a usb specific name in the global namespace.

Cc: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

These USB API functions will do the full authorization/deauthorization
to be used for a device. When authorized we effectively allow a
configuration to be set. Reverse that when deauthorized.

Effectively this means that we have to clean all the configuration
descriptors on deauthorize and reload them when we authorized. We could
do without throwing them out for wired devices, but for wireless, we can
read them only after authenticating, and thus, when authorizing an
authenticated device we would need to read them. So to simplify, always
release them on deauthorize(), re-read them on authorize().

Also fix leak reported by Ragner Magalhaes; in usb_deauthorize_device(),
bNumConfigurations was being set to zero before the for loop, and thus
the different raw descriptors where never being freed.
Signed-off-by: NInaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch takes hub.c:usb_new_device() and splits it in three parts:

- The actual actions of adding a new device (quirk detection,
  announcement and autoresume tracking)

- Actual discovery and probing of the configuration and interfaces
  (split into __usb_configure_device())

- Configuration of the On-the-go parameters (split into
  __usb_configure_device_otg()).

The fundamental reasons for doing this split are clarity (smaller
functions are easier to maintain) and to allow part of the code to be
reused when authorizing devices to connect.

When a device is authorized connection, we need to run through the
hoops we didn't run when it was connected but not authorized, which is
basically parsing the configurations and probing
them. usb_configure_device() will do that for us.
Signed-off-by: NInaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as947) changes the device initialization and enumeration
code in hub.c; now udev->devnum will be set to 0 while the device is
being accessed at address 0.  Until now this wasn't needed because the
address value was passed as part of urb->pipe; without that field the
device address must be stored elsewhere.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as944) adds an explicit "enabled" field to the
usb_host_endpoint structure and uses it in place of the current
mechanism.  This is merely a time-space tradeoff; it makes checking
whether URBs may be submitted to an endpoint simpler.  The existing
mechanism is efficient when converting urb->pipe to an endpoint
pointer, but it's not so efficient when urb->ep is used instead.

As a side effect, the procedure for enabling an endpoint is now a
little more complicated.  The ad-hoc inline code in usb.c and hub.c
for enabling ep0 is now replaced with calls to usb_enable_endpoint,
which is no longer static.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Some devices have a bug which causes them to send a 1-byte reply to
Get-Device-Status requests instead of 2 bytes as required by the
spec.  This doesn't play well with autosuspend, since we look for a
valid status reply to make sure the device is still present when it
resumes.  Without both bytes, we assume the device has been
disconnected.

Lack of the second byte shouldn't matter much, since the spec requires
it always to be equal to 0.  Hence this patch (as959) causes
finish_port_resume() to accept a 1-byte reply as valid.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Acked-by: NDavid Brownell <david-b@pacbell.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as937) fixes a minor bug in the autosuspend usage-counting
code.  Each hub's usage counter keeps track of the number of
unsuspended children.  However the current driver increments the
counter after registering a new child, by which time the child may
already have been suspended and caused the counter to go negative.
The obvious solution is to increment the counter before registering
the child.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Currently, the freezer treats all tasks as freezable, except for the kernel
threads that explicitly set the PF_NOFREEZE flag for themselves.  This
approach is problematic, since it requires every kernel thread to either
set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't
care for the freezing of tasks at all.

It seems better to only require the kernel threads that want to or need to
be frozen to use some freezer-related code and to remove any
freezer-related code from the other (nonfreezable) kernel threads, which is
done in this patch.

The patch causes all kernel threads to be nonfreezable by default (ie.  to
have PF_NOFREEZE set by default) and introduces the set_freezable()
function that should be called by the freezable kernel threads in order to
unset PF_NOFREEZE.  It also makes all of the currently freezable kernel
threads call set_freezable(), so it shouldn't cause any (intentional)
change of behaviour to appear.  Additionally, it updates documentation to
describe the freezing of tasks more accurately.

[akpm@linux-foundation.org: build fixes]
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NNigel Cunningham <nigel@nigel.suspend2.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch (as920) adds an extra level of protection to the
USB-Persist facility.  Now it will apply by default only to hubs; for
all other devices the user must enable it explicitly by setting the
power/persist device attribute.

The disconnect_all_children() routine in hub.c has been removed and
its code placed inline.  This is the way it was originally as part of
hub_pre_reset(); the revised usage in hub_reset_resume() is
sufficiently different that the code can no longer be shared.
Likewise, mark_children_for_reset() is now inline as part of
hub_reset_resume().  The end result looks much cleaner than before.

The sysfs interface is updated to add the new attribute file, and
there are corresponding documentation updates.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as919) unifies the code paths used for normal resume and
for reset-resume.  Earlier I had failed to note a section in the USB
spec which requires the host to resume a suspended port before
resetting it if the attached device is enabled for remote wakeup.
Since the port has to be resumed anyway, we might as well reuse the
existing code.

The main changes are:

	usb_reset_suspended_device() is eliminated.

	usb_root_hub_lost_power() is moved down next to the
	hub_reset_resume() routine, to which it is logically
	related.

	finish_port_resume() does a port reset() if the device's
	reset_resume flag is set.

	usb_port_resume() doesn't check whether the port is initially
	enabled if this is a USB-Persist sort of resume.

	Code to perform the port reset is added to the resume pathway
	for the non-CONFIG_USB_SUSPEND case.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as918) introduces a new USB driver method: reset_resume.
It is called when a device needs to be reset as part of a resume
procedure (whether because of a device quirk or because of the
USB-Persist facility), thereby taking over a role formerly assigned to
the post_reset method.  As a consequence, post_reset no longer needs
an argument indicating whether it is being called as part of a
reset-resume.  This separation of functions makes the code clearer.

In addition, the pre_reset and post_reset method return types are
changed; they now must return an error code.  The return value is
unused at present, but at some later time we may unbind drivers and
re-probe if they encounter an error during reset handling.

The existing pre_reset and post_reset methods in the usbhid,
usb-storage, and hub drivers are updated to match the new
requirements.  For usbhid the post_reset routine is also used for
reset_resume (duplicate method pointers); for the other drivers a new
reset_resume routine is added.  The change to hub.c looks bigger than
it really is, because mark_children_for_reset_resume() gets moved down
next to the new hub_reset_resume() routine.

A minor change to usb-storage makes the usb_stor_report_bus_reset()
routine acquire the host lock instead of requiring the caller to hold
it already.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>
CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as917) removes a now-unnecessary level of subroutine
nesting from hub.c.  Since usb_port_suspend() does nothing but call
hub_port_suspend(), and usb_port_resume() does nothing but call
hub_port_resume(), there's no reason to keep the routines separate.

Also included in the patch are a few cosmetic changes involving
whitespace and use of braces.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as916) completes the separation of code paths for suspend
and resume of root hubs as opposed to non-root devices.  Root hubs
will be power-managed through their bus_suspend and bus_resume
methods, whereas normal devices will use usb_port_suspend() and
usb_port_resume().

Changes to the hcd_bus_{suspend,resume} routines mostly represent
motion of code that was already present elsewhere.  They include:

	Adding debugging log messages,

	Setting the device state appropriately, and

	Adding a resume recovery time delay.

Changes to the port-suspend and port-resume routines in hub.c include:

	Removal of checks for root devices (since they will never
	be triggered), and

	Removal of checks for NULL or invalid device pointers (these
	were left over from earlier kernel versions and aren't needed
	at all).
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as915b) combines the public routine usb_port_suspend() and
the private routine __usb_port_suspend() into a single function.

By removing the explicit mention of otg_port in the call to
__usb_port_suspend(), we prevent a possible error in which the system
tries to perform HNP on the wrong port when a non-targeted device is
plugged into a non-OTG port.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Patch is to prevent the OTG host of doing 3 times enumeration of
device when the Host suspends for HNP.  The error code used in
this case is ENOTSUPP.
Signed-off-by: NVikram Pandita <vikram.pandita@ti.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Acked-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Okay, found it.  The root cause here was a missing CONFIG_USB_SUSPEND=y,
which means the hci_usb device never got marked as USB_STATE_SUSPENDED,
which then caused the loop to go on forever.

The system works fine now with CONFIG_USB_SUSPEND=y in the .config.

Here's the patch to prevent future lockups for this or other causes.
I no longer need it, but it does still seem a good idea.
Signed-off-by: NMark Lord <mlord@pobox.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as898) changes the port reset code in the hub driver.  If
a connect change occurs, it is reported the same way as a disconnect
(which of course is what it really is).

It also changes usb_reset_device(), to prevent the routine from futilely
retrying the reset after a disconnect has occurred.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as888) adds a new USB device quirk for devices which are
unable to resume correctly.  By using the new code added for the
USB-persist facility, it is a simple matter to reset these devices
instead of resuming them.  To get things kicked off, a quirk entry is
added for the Philips PSC805.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as886) adds the controversial USB-persist facility,
allowing USB devices to persist across a power loss during system
suspend.

The facility is controlled by a new Kconfig option (with appropriate
warnings about the potential dangers); when the option is off the
behavior will remain the same as it is now.  But when the option is
on, people will be able to use suspend-to-disk and keep their USB
filesystems intact -- something particularly valuable for small
machines where the root filesystem is on a USB device!
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This revised patch (as893c) improves the method used by the hub driver
to release its private data structure.  The current code is non-robust,
relying on a memory region not getting reused by another driver after
it has been freed.  The patch adds a reference count to the structure,
resolving the question of when to release it.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as892) removes the "locktree" routine from the hub driver.
It currently is used in only one place, by a single kernel thread;
hence it isn't doing any good.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This patch (as889) prevents the hub driver from trying to resume a
port when there is a new connection.  For one thing, the resume is not
needed -- the upcoming port reset will clear the suspend feature
automatically.  For another, on some systems the resume fails and
causes problems.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>