This patch (as1083) combines hub_quiesce() and hub_stop() into a
single routine. There's no point keeping them separate since they are
usually called together.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1071) combines hub_activate() and hub_restart() into a
single routine. There's no point keeping them separate, since they
are always called together.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1082) makes a small optimization to the way the hub
driver carries out port debouncing immediately after a hub is
activated (i.e., initialized, reset, or resumed). If any port-change
statuses are observed, the code will delay for a minimal debounce
period -- thereby making a good start at debouncing all the ports at
once.
If this wasn't sufficient then khubd will debounce any port that still
requires attention. But in most cases it should suffice; it's rare
for a device to need more than a minimal debounce delay. (In the
cases of hub initialization or reset even that is most likely not
needed, since any devices plugged in at such times have probably been
attached for a while.)
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1073) adds to khubd a way to recover from power-session
interruption caused by transient connect-change or enable-change
events. After the debouncing period, khubd attempts to do a
USB-Persist-style reset or reset-resume. If it works, the connection
will remain unscathed.
The upshot is that we will be more immune to noise caused by EMI. The
grace period is on the order of 100 ms, so this won't permit recovery
from the "accidentally knocked the USB cable out of its socket" type
of event, but it's a start.
As an added bonus, if a device was suspended when the system goes to
sleep then we no longer need to check for power-session interruptions
when the system wakes up. Khubd will naturally see the status change
while processing the device's parent hub and will do the right thing.
The remote_wakeup() routine is changed; now it expects the caller to
acquire the device lock rather than acquiring the lock itself.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1081) straightens out the logic of the hub_restart()
routine. Each port of the hub is scanned and the driver makes sure
that ports which are supposed to be disabled really _are_ disabled.
Any ports with a significant change in status are flagged in
hub->change_bits, so that khubd can focus on them without the need to
scan all the ports a second time -- which means the hub->activating
flag is no longer needed.
Also, it is now recognized explicitly that the only reason for
resuming a port which was not suspended is to carry out a reset-resume
operation, which happens only in a non-CONFIG_USB_SUSPEND setting.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts Linus's previous patch that is in mainline to make it
easier for the USB hub.c patches that follow this to apply cleanly. The
functionality will be added back in a followon patch in this series.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1080) makes a significant change to the way khubd
handles port connect-change and enable-change events. Both types of
event are now debounced, and the debouncing is carried out _before_ an
existing usb_device is unregistered, instead of afterward.
This means that drivers will have to deal with longer runs of errors
when a device is unplugged, but they are supposed to be prepared for
that in any case.
The advantage is that when an enable-change occurs (caused for example
by electromagnetic interference), the debouncing period will provide
time for the cause of the problem to die away. A simple port reset
(added in a forthcoming patch) will then allow us to recover from the
fault.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1070) creates a new subroutine to check whether a device
can be resumed. This code is needed even when CONFIG_USB_SUSPEND
isn't set, because devices do suspend themselves when the root hub
(and hence the entire bus) is suspended, and power sessions can get
lost during a system sleep even without individual port suspends.
The patch also fixes a loose end in USB-Persist reset-resume handling.
When a low- or full-speed device is attached to an EHCI's companion
controller, the port handoff during resume will cause the companion
port's connect-status-change feature to be set. If that flag isn't
cleared, the port-reset code will think it indicates that the device
has been unplugged and the reset-resume will fail.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts Alan's previous patch so that the recent Hub changes will
apply cleanly. The above mentioned patch was needed for 2.6.26 to work
properly.
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Lukas Hejtmanek <xhejtman@ics.muni.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts commit e872154921.
Andrey Borzenkov reports that it resulted in a totally hung machine for
him when loading the OHCI driver. Extensive netconsole capture with
SysRq output shows that modprobe gets stuck in ohci_hub_status_data()
when probing and enabling the OHCI controller, see for example
http://lkml.org/lkml/2008/7/5/236
for an analysis.
The problem appears to be an interrupt flood triggered by the commit
that gets reverted, and Andrey confirmed that the revert makes things
work for him again.
Reported-and-tested-by: Andrey Borzenkov <arvidjaar@mail.ru>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Brownell <david-b@pacbell.net>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch (as1111) fixes a bug in the hub driver. When a hub
resumes, disconnections that occurred while the hub was suspended are
lost.
A completely different fix for this problem has already been accepted
for 2.6.27; however the problem still needs to be handled in 2.6.26.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Lukas Hejtmanek <xhejtman@ics.muni.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch tries to identify which devices are able to accept
reset-resume handling, by checking that there is at least one
interface driver bound and that all of the drivers have a reset_resume
method defined. If these conditions don't hold then during resume
processing, the device is logicall disconnected.
This is only a temporary fix. Later on we will explicitly unbind
drivers that can't handle reset-resumes.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Oliver Neukum <oliver@neukum.org>
Cc: Pavel Machek <pavel@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1096) fixes an annoying problem: When a full-speed or
low-speed device is plugged into an EHCI controller, it fails to
enumerate at high speed and then is handed over to the companion
controller. But usbcore logs a misleading and unwanted error message
when the high-speed enumeration fails.
The patch adds a new HCD method, port_handed_over, which asks whether
a port has been handed over to a companion controller. If it has, the
error message is suppressed.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
There is a potential deadlock when the usb_generic driver is unbound
from a device. The problem is that generic_disconnect() is called
with the device lock held, and it removes a bunch of device attributes
from sysfs. If a user task happens to be running an attribute method
at the time, the removal will block until the method returns. But at
least one of the attribute methods (the store routine for power/level)
needs to acquire the device lock!
This patch (as1093) eliminates the deadlock by moving the calls to
create and remove the sysfs attributes from the usb_generic driver
into usb_new_device() and usb_disconnect(), where they can be invoked
without holding the device lock.
Besides, the other sysfs attributes are created when the device is
registered and removed when the device is unregistered. So it seems
only fitting for the extra attributes to be created and removed at the
same time.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
For WUSB devices, usb_dev.devnum is a device index and not the real
device address (which is managed by wusbcore). Therefore, only set
devnum once (in choose_address()) and never change it.
Signed-off-by: David Vrabel <david.vrabel@csr.com>
Cc: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We need to be able to call ep0_reinit() [renamed to usb_ep0_reinit()]
from the WUSB security code. The reason is that when we authenticate
the device, it's address changes (from having bit 7 set to having it
cleared). Thus, we need to signal the USB stack to reinitialize EP0,
so the status with the previous address kept at the HCD layer is
cleared and properly reinitialized.
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
A WUSB device gets his address during the connection phase; later on,
during the authenthication phase (driven from user space) we assign
the final address. So we need to skip in hub_port_init() the actual
setting of the address for WUSB devices.
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Modify choose_address() so it knows about our special scheme of
addressing WUSB devices (1:1 w/ port number).
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1069b) changes the way OHCI root-hub status-change
interrupts are enabled. Currently a special HCD method,
hub_irq_enable(), is called when the hub driver is finished using a
root hub. This approach turns out to be subject to races, resulting
in unnecessary polling.
The patch does away with the method entirely. Instead, the driver
automatically enables the RHSC interrupt when no more status changes
are present. This scheme is safe with controllers using
level-triggered semantics for their interrupt flags.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1077) logs an error message whenever the kernel is
unable to enumerate a new USB device.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1048) extends the descriptor checking after a device is
reset. Now the SerialNumber string descriptor is compared to its old
value, in addition to the device and configuration descriptors.
As a consequence, the kmalloc() call in usb_string() is now on the
error-handling pathway for usb-storage. Hence its allocation type is
changed to GFO_NOIO.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1047) removes the USB_PERSIST Kconfig option, enabling
it permanently. It also prevents the power/persist attribute from
being created for hub devices; there's no point in having it since
USB-PERSIST is always turned on for hubs.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg 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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg 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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg 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: Matthew 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: Greg 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: Sarah Sharp <sarah.a.sharp@intel.com>
Signed-off-by: Greg 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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg 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: Greg Kroah-Hartman <gregkh@suse.de>
This patch hands over the port to the companion when the
hub_port_connect_change fails.
Signed-off-by: Balaji Rao <balajirrao@gmail.com>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg 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: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg 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: Alan Stern <stern@rowland.harvard.edu>
CC: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg 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: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus 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: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Brownell <david-b@pacbell.net>
Cc: David Miller <davem@davemloft.net>
Cc: Dely L Sy <dely.l.sy@intel.com>
Signed-off-by: Greg 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: Jason Xiao <jidong.xiao@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg 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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as981) removes the remaining nontrivial usages of
urb->status from usbcore.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg 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: Greg 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: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg 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: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg 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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg 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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg 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: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg 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: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg 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: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Nigel 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus 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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
