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>
This patch (as987) changes the way FREEZE and PRETHAW suspend events
are handled in usbcore. The decision about whether or not to ignore
them for non-root devices is pushed down into the USB-device driver,
instead of being made in the core code.
This is appropriate, since devices exported to a virtualized guest or
over a network may indeed need to handle these types of suspend, even
though normal devices don't.
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>
If called and the device is not authorized to be used, then we won't
choose a configuration (as they are not a concept that exists for an
unauthorized device). However, the device is added to the system.
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg 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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg 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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg 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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as885) moves the root-hub bus_suspend() and bus_resume()
method calls from the hub driver's suspend and resume methods into the
usb_generic driver methods, where they make just as much sense.
Their old locations were not fully correct. For example, in a kernel
compiled without CONFIG_USB_SUSPEND, if one were to do:
echo -n 1-0:1.0 >/sys/bus/usb/drivers/hub/unbind
to unbind the hub driver from a root hub, there would then be no way
to suspend that root hub. Attempts to put the system to sleep would
fail; the USB controller driver would refuse to suspend because the
root hub was still active.
The patch also makes a very slight change in the way devices with no
driver are handled during suspend. Rather than doing a standard USB
port-suspend directly, now the suspend routine in usb_generic is
called. In practice this should never affect anyone.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as884) finally implements the time-saving semantics
possible with the Power Management FREEZE and PRETHAW events. Their
proper handling requires only that devices be quiesced, with
interrupts and DMA turned off; non-root USB devices don't actually
need to be put in a suspended state. The patch checks and avoids
doing the suspend call when possible.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Some USB devices do have a configuration 0, in contravention of the
USB spec. Normally 0 is supposed to indicate that a device is
unconfigured.
While we can't change what the device is doing, we can change usbcore.
This patch (as852) allows usb_set_configuration() to accept a config
value of -1 as indicating that the device should be unconfigured. The
request actually sent to the device will still contain 0 as the value.
But even if the device does have a configuration 0, dev->actconfig
will be set to NULL and dev->state will be set to USB_STATE_ADDRESS.
Without some sort of special-case handling like this, there is no way
to unconfigure these non-compliant devices.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Windows Mobile 5 based devices described as supporting "ActiveSync":
- Speak RNDIS but lack the CDC and union descriptors. This patch
updates the cdc ethernet code to fake ACM descriptors we need.
- Require RNDIS_MSG_QUERY messages to include a buffer of the size the
response should generate. This patch updates the rndis host code to
pass this will-be-ignored data.
The resulting RNDIS host code has been reported to work with several
WM5 based devices.
(Note that a fancier patch is available at synce.sf.net.)
Some bugfixes, affecting not just ActiveSync:
(a) when cleaning up after RNDS init fails, scrub the second interface
just like cdc_ether does, so disconnect won't oops.
(b) handle peripherals that use the pad-to-end-of-packet option; some
devices can't talk to us if that option doesn't work.
(c) when choosing configurations, don't forget about an RNDIS config
just because the RNDIS driver is dynamically linked.
Cleanup, streamlining, bugfixes, Kconfig, and matching hub driver update.
Also for paranoia's sake, refuse to talk to something that looks like a
real modem instead of RNDIS.
Signed-off-by: Ole Andre Vadla Ravnaas <oleavr@gmail.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as741) makes the non-hub parts of usbcore actually use the
autosuspend facilities added by an earlier patch.
Devices opened through usbfs are autoresumed and then
autosuspended upon close.
Likewise for usb-skeleton.
Devices are autoresumed for usb_set_configuration.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg 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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg 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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg 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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg 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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg 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: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
