linux.git/drivers/usb/core/hcd.h, branch master

USB: make hcd.h public (drivers dependency)

2010-05-20T20:21:30+00:00

The usbcore headers: hcd.h and hub.h are shared between usbcore,
HCDs and a couple of other drivers (e.g. USBIP modules).
So, it makes sense to move them into a more public location and
to cleanup dependency of those modules on kernel internal headers.
This patch moves hcd.h from drivers/usb/core into include/linux/usb/

Signed-of-by: Eric Lescouet 
Cc: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

USB: Move hcd free_dev call into usb_disconnect to fix oops

2010-03-02T22:54:13+00:00

USB: Move hcd free_dev call into usb_disconnect

I found a way to oops the kernel:

1. Open a USB device through devio.
2. Remove the hcd module in the host kernel.
3. Close the devio file descriptor.

The problem is that closing the file descriptor does usb_release_dev
as it is the last reference.  usb_release_dev then tries to invoke
the hcd free_dev function (or rather dereferencing the hcd driver
struct).  This causes an oops as the hcd driver has already been
unloaded so the struct is gone.

This patch tries to fix this by bringing the free_dev call earlier
and into usb_disconnect.  I have verified that repeating the
above steps no longer crashes with this patch applied.

Signed-off-by: Herbert Xu 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

USB: convert to the runtime PM framework

2010-03-02T22:54:12+00:00

This patch (as1329) converts the USB stack over to the PM core's
runtime PM framework.  This involves numerous changes throughout
usbcore, especially to hub.c and driver.c.  Perhaps the most notable
change is that CONFIG_USB_SUSPEND now depends on CONFIG_PM_RUNTIME
instead of CONFIG_PM.

Several fields in the usb_device and usb_interface structures are no
longer needed.  Some code which used to depend on CONFIG_USB_PM now
depends on CONFIG_USB_SUSPEND (requiring some rearrangement of header
files).

The only visible change in behavior should be that following a system
sleep (resume from RAM or resume from hibernation), autosuspended USB
devices will be resumed just like everything else.  They won't remain
suspended.  But if they aren't in use then they will naturally
autosuspend again in a few seconds.

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

USB: Add call to notify xHC of a device reset.

2010-03-02T22:53:12+00:00

Add a new host controller driver method, reset_device(), that the USB core
will use to notify the host of a successful device reset.  The call may
fail due to out-of-memory errors; attempt the port reset sequence again if
that happens.  Update hub_port_init() to allow resetting a configured
device.

Signed-off-by: Sarah Sharp 
Signed-off-by: Greg Kroah-Hartman

const: constify remaining dev_pm_ops

2009-12-15T16:53:25+00:00

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

USB: Check bandwidth when switching alt settings.

2009-12-11T19:55:27+00:00

Make the USB core check the bandwidth when switching from one
interface alternate setting to another.  Also check the bandwidth
when resetting a configuration (so that alt setting 0 is used).  If
this check fails, the device's state is unchanged.  If the device
refuses the new alt setting, re-instate the old alt setting in the
host controller hardware.

If a USB device doesn't have an alternate interface setting 0, install
the first alt setting in its descriptors when a new configuration is
requested, or the device is reset.

Add a mutex per root hub to protect bandwidth operations:
adding/reseting/changing configurations, and changing alternate interface
settings.  We want to ensure that the xHCI host controller and the USB
device are set up for the same configurations and alternate settings.
There are two (possibly three) steps to do this:

 1. The host controller needs to check that bandwidth is available for a
    different setting, by issuing and waiting for a configure endpoint
    command.
 2. Once that returns successfully, a control message is sent to the
    device.
 3. If that fails, the host controller must be notified through another
    configure endpoint command.

The mutex is used to make these three operations seem atomic, to prevent
another driver from using more bandwidth for a different device while
we're in the middle of these operations.

While we're touching the bandwidth code, rename usb_hcd_check_bandwidth()
to usb_hcd_alloc_bandwidth().  This function does more than just check
that the bandwidth change won't exceed the bus bandwidth; it actually
changes the bandwidth configuration in the xHCI host controller.

Signed-off-by: Sarah Sharp 
Signed-off-by: Greg Kroah-Hartman

USB: Add hub descriptor update hook for xHCI

2009-09-23T13:46:40+00:00

Add a hook for updating xHCI internal structures after khubd fetches the
hub descriptor and sets up the hub's TT information.  The xHCI driver must
update the internal structures before devices under the hub can be
enumerated.

Signed-off-by: Sarah Sharp 
Signed-off-by: Greg Kroah-Hartman

USB: fix the clear_tt_buffer interface

2009-07-12T22:16:38+00:00

This patch (as1255) updates the interface for calling
usb_hub_clear_tt_buffer().  Even the name of the function is changed!

When an async URB (i.e., Control or Bulk) going through a high-speed
hub to a non-high-speed device is cancelled or fails, the hub's
Transaction Translator buffer may be left busy still trying to
complete the transaction.  The buffer has to be cleared; that's what
usb_hub_clear_tt_buffer() does.

It isn't safe to send any more URBs to the same endpoint until the TT
buffer is fully clear.  Therefore the HCD needs to be told when the
Clear-TT-Buffer request has finished.  This patch adds a callback
method to struct hc_driver for that purpose, and makes the hub driver
invoke the callback at the proper time.

The patch also changes a couple of names; "hub_tt_kevent" and
"tt.kevent" now look rather antiquated.

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

USB: Support for bandwidth allocation.

2009-06-16T04:44:49+00:00

Originally, the USB core had no support for allocating bandwidth when a
particular configuration or alternate setting for an interface was
selected.  Instead, the device driver's URB submission would fail if
there was not enough bandwidth for a periodic endpoint.  Drivers could
work around this, by using the scatter-gather list API to guarantee
bandwidth.

This patch adds host controller API to allow the USB core to allocate or
deallocate bandwidth for an endpoint.  Endpoints are added to or dropped
from a copy of the current schedule by calling add_endpoint() or
drop_endpoint(), and then the schedule is atomically evaluated with a
call to check_bandwidth().  This allows all the endpoints for a new
configuration or alternate setting to be added at the same time that the
endpoints from the old configuration or alt setting are dropped.

Endpoints must be added to the schedule before any URBs are submitted to
them.  The HCD must be allowed to reject a new configuration or alt
setting before the control transfer is sent to the device requesting the
change.  It may reject the change because there is not enough bandwidth,
not enough internal resources (such as memory on an embedded host
controller), or perhaps even for security reasons in a virtualized
environment.

If the call to check_bandwidth() fails, the USB core must call
reset_bandwidth().  This causes the schedule to be reverted back to the
state it was in just after the last successful check_bandwidth() call.

If the call succeeds, the host controller driver (and hardware) will have
changed its internal state to match the new configuration or alternate
setting.  The USB core can then issue a control transfer to the device to
change the configuration or alt setting.  This allows the core to test new
configurations or alternate settings before unbinding drivers bound to
interfaces in the old configuration.

WIP:

The USB core must add endpoints from all interfaces in a configuration
to the schedule, because a driver may claim that interface at any time.
A slight optimization might be to add the endpoints to the schedule once
a driver claims that interface.  FIXME

This patch does not cover changing alternate settings, but it does
handle a configuration change or de-configuration.  FIXME

The code for managing the schedule is currently HCD specific.  A generic
scheduling algorithm could be added for host controllers without
built-in scheduling support.  For now, if a host controller does not
define the check_bandwidth() function, the call to
usb_hcd_check_bandwidth() will always succeed.

Signed-off-by: Sarah Sharp 
Signed-off-by: Greg Kroah-Hartman

USB: Support for addressing a USB device under xHCI

2009-06-16T04:44:49+00:00

Add host controller driver API and a slot_id variable to struct
usb_device.  This allows the xHCI host controller driver to ask the
hardware to allocate a slot for the device when a struct usb_device is
allocated.  The slot needs to be allocated at that point because the
hardware can run out of internal resources, and we want to know that very
early in the device connection process.  Don't call this new API for root
hubs, since they aren't real devices.

Add HCD API to let the host controller choose the device address.  This is
especially important for xHCI hardware running in a virtualized
environment.  The guests running under the VM don't need to know which
addresses on the bus are taken, because the hardware picks the address for
them.  Announce SuperSpeed USB devices after the address has been assigned
by the hardware.

Don't use the new get descriptor/set address scheme with xHCI.  Unless
special handling is done in the host controller driver, the xHC can't
issue control transfers before you set the device address.  Support for
the older addressing scheme will be added when the xHCI driver supports
the Block Set Address Request (BSR) flag in the Address Device command.

Signed-off-by: Sarah Sharp 
Signed-off-by: Greg Kroah-Hartman