linux-stable.git/drivers/usb/core/driver.c, branch linux-2.6.33.y

USB: don't let errors prevent system sleep

2011-07-13T03:31:25+00:00

commit 0af212ba8f123c2eba151af7726c34a50b127962 upstream.

This patch (as1464) implements the recommended policy that most errors
during suspend or hibernation should not prevent the system from going
to sleep.  In particular, failure to suspend a USB driver or a USB
device should not prevent the sleep from succeeding:

Failure to suspend a device won't matter, because the device will
automatically go into suspend mode when the USB bus stops carrying
packets.  (This might be less true for USB-3.0 devices, but let's not
worry about them now.)

Failure of a driver to suspend might lead to trouble later on when the
system wakes up, but it isn't sufficient reason to prevent the system
from going to sleep.

Signed-off-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

USB: obey the sysfs power/wakeup setting

2010-08-02T17:26:41+00:00

commit 48826626263d4a61d06fd8c5805da31f925aefa0 upstream.

This patch (as1403) is a partial reversion of an earlier change
(commit 5f677f1d45b2bf08085bbba7394392dfa586fa8e "USB: fix remote
wakeup settings during system sleep").  After hearing from a user, I
realized that remote wakeup should be enabled during system sleep
whenever userspace allows it, and not only if a driver requests it
too.

Indeed, there could be a device with no driver, that does nothing but
generate a wakeup request when the user presses a button.  Such a
device should be allowed to do its job.

The problem fixed by the earlier patch -- device generating a wakeup
request for no reason, causing system suspend to abort -- was also
addressed by a later patch ("USB: don't enable remote wakeup by
default", accepted but not yet merged into mainline).  The device
won't be able to generate the bogus wakeup requests because it will be
disabled for remote wakeup by default.  Hence this reversion will not
re-introduce any old problems.

Signed-off-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

USB: fix remote wakeup settings during system sleep

2010-05-12T22:02:36+00:00

This is a backport of commit 5f677f1d45b2bf08085bbba7394392dfa586fa8e.
Some of the functionality had to be removed, but it should still fix
the webcam problem.

This patch (as1363b) changes the way USB remote wakeup is handled
during system sleeps.  It won't be enabled unless an interface driver
specifically needs it.  Also, it won't be enabled during the FREEZE or
QUIESCE phases of hibernation, when the system doesn't respond to
wakeup events anyway.

This will fix problems people have reported with certain USB webcams
that generate wakeup requests when they shouldn't, and as a result
cause system suspends to fail.  See

	https://bugs.launchpad.net/ubuntu/+source/linux/+bug/515109


Signed-off-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

USB: remove debugging message for uevent constructions

2010-03-15T16:06:55+00:00

commit cceffe9348f93188d7811bda95924d4bd3040d0f upstream.

This patch (as1332) removes an unneeded and annoying debugging message
announcing all USB uevent constructions.

Signed-off-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

USB: add remove_id sysfs attr for usb drivers

2009-12-11T19:55:26+00:00

Accroding commit 0994375e, which is adding remove_id sysfs attr
for pci drivers, for management tools dynamically bind/unbind
a pci/usb devices to a specified drivers; with this patch,
the management tools can be simplied.

And the original code didn't handle the failure of
usb_create_newid_file, fixed in this patch.

Signed-off-by: CHENG Renquan 
Signed-off-by: Greg Kroah-Hartman

USB: prepare for changover to Runtime PM framework

2009-12-11T19:55:25+00:00

This patch (as1303) revises the USB Power Management infrastructure to
make it compatible with the new driver-model Runtime PM framework:

	Drivers are no longer allowed to access intf->pm_usage_cnt
	directly; the PM framework manages its own usage counters.

	usb_autopm_set_interface() is eliminated, because it directly
	sets intf->pm_usage_cnt.

	usb_autopm_enable() and usb_autopm_disable() are eliminated,
	because they call usb_autopm_set_interface().

	usb_autopm_get_interface_no_resume() and
	usb_autopm_put_interface_no_suspend() are added.  They
	correspond to pm_runtime_get_noresume() and
	pm_runtime_put_noidle() in the PM framework.

	The power/level attribute no longer accepts "suspend", only
	"on" and "auto".  The PM framework doesn't allow devices to be
	forced into a suspended mode.

The hub driver contains the only code that violates the new
guidelines.  It is updated to use the new interface routines instead.

Signed-off-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

USB: remove the auto_pm flag

2009-12-11T19:55:21+00:00

This patch (as1302) removes the auto_pm flag from struct usb_device.
The flag's only purpose was to distinguish between autosuspends and
external suspends, but that information is now available in the
pm_message_t argument passed to suspend methods.

Signed-off-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

USB: fix missing error check in probing

2009-09-23T13:46:39+00:00

usb: check for IO errors usb_set_interface can return

if they happen while unbinding a flag is set to retry upon probe
if they happen during probe they are handled as probe errors

Signed-off-by: Oliver Neukum 
Acked-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

USB: make intf.pm_usage an atomic_t

2009-09-23T13:46:23+00:00

This patch (as1260) changes the pm_usage_cnt field in struct
usb_interface from an int to an atomic_t.  This is so that drivers can
invoke the usb_autopm_get_interface_async() and
usb_autopm_put_interface_async() routines without locking and without
fear of corrupting the pm_usage_cnt value.

Signed-off-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

USB: add API for userspace drivers to "claim" ports

2009-09-23T13:46:22+00:00

This patch (as1258) implements a feature that users have been asking
for: It gives programs the ability to "claim" a port on a hub, via a
new usbfs ioctl.  A device plugged into a "claimed" port will not be
touched by the kernel beyond the immediate necessities of
initialization and enumeration.

In particular, when a device is plugged into a "claimed" port, the
kernel will not select and install a configuration.  And when a config
is installed by usbfs or sysfs, the kernel will not probe any drivers
for any of the interfaces.  (However the kernel will fetch various
string descriptors during enumeration.  One could argue that this
isn't really necessary, but the strings are exported in sysfs.)

The patch does not guarantee exclusive access to these devices; it is
still possible for more than one program to open the device file
concurrently.  Programs are responsible for coordinating access among
themselves.

A demonstration program showing how to use the new interface can be 
found in an attachment to

	http://marc.info/?l=linux-usb&m=124345857431452&w=2

The patch also makes a small simplification to the hub driver,
replacing a bunch of more-or-less useless variants of "out of memory"
with a single message.

Signed-off-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman