linux.git/drivers/usb/core/message.c, branch v2.6.29

USB: usb_get_string should check the descriptor type

2009-02-27T22:40:50+00:00

This patch (as1218) fixes a problem with a radio-control joystick used
in the "walkera 4#3" helicopter.  This device responds to the initial
Get-String-Descriptor request for string 0 (which is really the list
of supported languages) by sending its config descriptor!  The
usb_get_string() routine needs to check whether it got the right
type of descriptor.

Oddly enough, this sort of check is already present in
usb_get_descriptor().  The patch changes the error code from -EPROTO
to -ENODATA, because -EPROTO shows up in so many other contexts to
indicate a hardware failure rather than a firmware error.

Signed-off-by: Alan Stern 
Tested-by: Guillermo Jarabo 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman 

===================================================================

USB: fix toggle mismatch in disable_endpoint paths

2009-01-28T00:15:32+00:00

This patch (as1200) finishes some fixes that were left incomplete by
an earlier patch.

Although nobody has addressed this issue in the past, it turns out
that we need to distinguish between two different modes of disabling
and enabling endpoints.  In one mode only the data structures in
usbcore are affected, and in the other mode the host controller and
device hardware states are affected as well.

The earlier patch added an extra argument to the routines in the
enable_endpoint pathways to reflect this difference.  This patch adds
corresponding arguments to the disable_endpoint pathways.  Without
this change, the endpoint toggle state can get out of sync between
the host and the device.  The exact mechanism depends on the details
of the host controller (whether or not it stores its own copy of the
toggle values).

Signed-off-by: Alan Stern 
Reported-by: Dan Streetman 
Tested-by: Dan Streetman 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

USB: re-enable interface after driver unbinds

2009-01-07T18:00:13+00:00

This patch (as1197) fixes an error introduced recently.  Since a
significant number of devices can't handle Set-Interface requests, we
no longer call usb_set_interface() when a driver unbinds from an
interface, provided the interface is already in altsetting 0.  However
the interface still does get disabled, and the call to
usb_set_interface() was the only thing re-enabling it.  Since the
interface doesn't get re-enabled, further attempts to use it fail.

So the patch adds a call to usb_enable_interface() when a driver
unbinds and the interface is in altsetting 0.  For this to work
right, the interface's endpoints have to be re-enabled but their
toggles have to be left alone.  Therefore an additional argument is
added to usb_enable_endpoint() and usb_enable_interface(), a flag
indicating whether or not the endpoint toggles should be reset.

This is a forward-ported version of a patch which fixes Bugzilla
#12301.

Signed-off-by: Alan Stern 
Reported-by: David Roka 
Reported-by: Erik Ekman 
Tested-by: Erik Ekman 
Tested-by: Alon Bar-Lev 
Signed-off-by: Greg Kroah-Hartman

USB: cancel pending Set-Config requests if userspace gets there first

2009-01-07T18:00:12+00:00

This patch (as1195) eliminates a potential problem identified by
Oliver Neukum.  When a driver queues an asynchronous Set-Config
request using usb_driver_set_configuration(), the request should be
cancelled if userspace changes the configuration first.  The patch
introduces a linked list of pending async Set-Config requests, and
uses it to invalidate the requests for a particular device whenever
that device's configuration is set.

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

USB: utilize the bus notifiers

2009-01-07T18:00:08+00:00

This patch (as1185) makes usbcore take advantage of the bus
notifications sent out by the driver core.  Now we can create all our
device and interface attribute files before the device or interface
uevent is broadcast.

A side effect is that we no longer create the endpoint "pseudo"
devices at the same time as a device or interface is registered -- it
seems like a bad idea to try registering an endpoint before the
registration of its parent is complete.  So the routines for creating
and removing endpoint devices have been split out and renamed, and
they are called explicitly when needed.  A new bitflag is used for
keeping track of whether or not the interface's endpoint devices have
been created, since (just as with the interface attributes) they vary
with the altsetting and hence can be changed at random times.

Signed-off-by: Alan Stern 
Cc: Kay Sievers 
Signed-off-by: Greg Kroah-Hartman

USB: Introduce usb_queue_reset() to do resets from atomic contexts

2009-01-07T17:59:53+00:00

This patch introduces a new call to be able to do a USB reset from an
atomic contect. This is quite helpful in USB callbacks to handle
errors (when the only thing that can be done is to do a device
reset).

It is done queuing a work struct that will do the actual reset. The
struct is "attached" to an interface so pending requests from an
interface are removed when said interface is unbound from the driver.

The call flow then becomes:

usb_queue_reset_device()
  __usb_queue_reset_device() [workqueue]
    usb_reset_device()

usb_probe_interface()
  usb_cancel_queue_reset()      [error path]

usb_unbind_interface()
  usb_cancel_queue_reset()

usb_driver_release_interface()
  usb_cancel_queue_reset()

Note usb_cancel_queue_reset() needs smarts to try not to unqueue when
it is actually being executed. This happens when we run the reset from
the workqueue: usb_reset_device() is called and on interface unbind
time, usb_cancel_queue_reset() would be called. That would deadlock on
cancel_work_sync(). To avoid that, we set (before running
usb_reset_device()) usb_intf->reset_running and clear it inmediately
after returning.

Patch is against 2.6.28-rc2 and depends on
http://marc.info/?l=linux-usb&m=122581634925308&w=2 (as submitted by
Alan Stern).

Signed-off-by: Inaky Perez-Gonzalez 
Cc: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

USB: avoid needless address-taking of function parameters

2009-01-07T17:59:50+00:00

There's no need to take the address of the function params or local variables
when the direct value byteswapping routines are available.

Signed-off-by: Harvey Harrison 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

USB: don't register endpoints for interfaces that are going away

2008-11-13T22:45:00+00:00

This patch (as1155) fixes a bug in usbcore.  When interfaces are
deleted, either because the device was disconnected or because of a
configuration change, the extra attribute files and child endpoint
devices may get left behind.  This is because the core removes them
before calling device_del().  But during device_del(), after the
driver is unbound the core will reinstall altsetting 0 and recreate
those extra attributes and children.

The patch prevents this by adding a flag to record when the interface
is in the midst of being unregistered.  When the flag is set, the
attribute files and child devices will not be created.

Signed-off-by: Alan Stern 
Cc: stable  [2.6.27, 2.6.26, 2.6.25]
Signed-off-by: Greg Kroah-Hartman

USB: remove warn() macro from usb drivers

2008-10-17T21:41:09+00:00

USB should not be having it's own printk macros, so remove warn() and
use the system-wide standard of dev_warn() wherever possible.  In the
few places that will not work out, use a basic printk().

Signed-off-by: Greg Kroah-Hartman

USB: fix interface unregistration logic

2008-08-14T00:32:50+00:00

This patch (as1122) fixes a bug: When an interface is unregistered,
its children (sysfs files and endpoint devices) are unregistered after
it instead of before.

Signed-off-by: Alan Stern 
Tested-by: Kay Sievers 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman