Commit Graph

232 Commits

Author SHA1 Message Date
Alan Stern
84ebc10294 USB: remove CONFIG_USB_SUSPEND option
This patch (as1675) removes the CONFIG_USB_SUSPEND option, essentially
replacing it everywhere with CONFIG_PM_RUNTIME (except for one place
in hub.c, where it is replaced with CONFIG_PM because the code needs
to be used in both runtime and system PM).  The net result is code
shrinkage and simplification.

There's very little point in keeping CONFIG_USB_SUSPEND because almost
everybody enables it.  The few that don't will find that the usbcore
module has gotten somewhat bigger and they will have to take active
measures if they want to prevent hubs from being runtime suspended.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-28 11:10:22 -07:00
Ming Lei
303f084792 USB: adds comment on suspend callback
This patch adds comments on interface driver suspend callback
to emphasize that the failure return value is ignored by
USB core in system sleep context, so do not try to recover
device for this case and let resume/reset_resume callback
handle the suspend failure if needed.

Also kerneldoc for usb_suspend_both() is updated with the
fact.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-25 10:55:46 -07:00
Nishanth Menon
dad3cab3e0 USB: fix trivial usb_device kernel-doc errors
Fix trivial kernel-doc warnings:
Warning(include/linux/usb.h:574): No description found for parameter 'usb3_lpm_enabled'
Warning(include/linux/usb.h:574): Excess struct/union/enum/typedef member 'usb_classdev' description in 'usb_device'
Warning(include/linux/usb.h:574): Excess struct/union/enum/typedef member 'usbfs_dentry' description in 'usb_device'

Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Kosina <trivial@kernel.org>
Cc: linux-usb@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-15 11:45:16 -07:00
Alan Stern
da0aa7169b USB: add usb_hcd_{start,end}_port_resume
This patch (as1649) adds a mechanism for host controller drivers to
inform usbcore when they have begun or ended resume signalling on a
particular root-hub port.  The core will then make sure that the root
hub does not get runtime-suspended while the port resume is going on.

Since commit 596d789a21 (USB: set hub's
default autosuspend delay as 0), the system tries to suspend hubs
whenever they aren't in use.  While a root-hub port is being resumed,
the root hub does not appear to be in use.  Attempted runtime suspends
fail because of the ongoing port resume, but the PM core just keeps on
trying over and over again.  We want to prevent this wasteful effort.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-25 15:06:01 -08:00
Bjørn Mork
17b72feb2b USB: add USB_DEVICE_INTERFACE_CLASS macro
Matching on device and interface class with with unspecified
subclass and protocol is sometimes useful.  This is slightly
different from USB_DEVICE_AND_INTERFACE_INFO which requires
the full interface class/subclass/protocol triplet.

Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-31 12:58:11 -07:00
Alan Stern
bfd1e91013 USB: speed up usb_bus_resume()
This patch (as1620) speeds up USB root-hub resumes in the common case
where every enabled port has its suspend feature set (which currently
will be true for every runtime resume of the root hub).  If all the
enabled ports are suspended then resuming the root hub won't resume
any of the downstream devices.  In this case there's no need for a
Resume Recovery delay, because that delay is meant to give devices a
chance to get ready for active use.

To keep track of the port suspend features, the patch adds a
"port_is_suspended" flag to struct usb_device.  This has to be tracked
separately from the device's state; it's entirely possible for a USB-2
device to be suspended while the suspend feature on its parent port is
clear.  The reason is that devices will go into suspend whenever their
parent hub does.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reviewed-by: Peter Chen <peter.chen@freescale.com>
Tested-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-24 14:51:22 -07:00
Alan Stern
969ddcfc95 USB: hub_for_each_child should skip unconnected ports
This patch (as1619) improves the interface to the "hub_for_each_child"
macro.  The name clearly suggests that the macro iterates over child
devices; it does not suggest that the loop will also iterate over
unnconnected ports.

The patch changes the macro so that it will skip over unconnected
ports and iterate only the actual child devices.  The two existing
call sites are updated to avoid testing for a NULL child pointer,
which is now unnecessary.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-24 14:51:21 -07:00
Alan Stern
a03bede5c7 USB: update documentation for URB_ISO_ASAP
This patch (as1611) updates the USB documentation and kerneldoc to
give a more precise meaning for the URB_ISO_ASAP flag and to explain
more of the details of scheduling for isochronous URBs.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-22 11:10:24 -07:00
Greg Kroah-Hartman
2c78040c3e USB: usb.h: remove dbg() macro
There are no users of this macro anymore in the kernel tree, so finally
delete it.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-17 11:16:13 -07:00
Lan Tianyu
f7ac7787ad usb/acpi: Use ACPI methods to power off ports.
Upcoming Intel systems will have an ACPI method to control whether a USB
port can be completely powered off.  The implication of powering off a
USB port is that the device and host sees a physical disconnect, and
subsequent port connections and remote wakeups will be lost.

Add a new function, usb_acpi_power_manageable(), that can be used to
find whether the usb port has ACPI power resources that can be used to
power on and off the port on these machines. Also add a new function
called usb_acpi_set_power_state() that controls the port power via these
ACPI methods.

When the USB core calls into the xHCI hub driver to power off a port,
check whether the port can be completely powered off via this new ACPI
mechanism.  If so, call into these new ACPI methods.  Also use the ACPI
methods when the USB core asks to power on a port.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-10 13:04:01 -07:00
Lan Tianyu
05f916894a usb/acpi: Store info on device removability.
In the upcoming USB port power off patches, we need to know whether a
USB port can ever see a disconnect event.  Often USB ports are internal
to a system, and users can't disconnect USB devices from that port.
Sometimes those ports will remain empty, because the OEM chose not to
connect an internal USB device to that port.

According to ACPI Spec 9.13, PLD indicates whether USB port is
user visible and _UPC indicates whether a USB device can be connected to
the USB port (we'll call this "connectible").  Here's a matrix of the
possible combinations:

Visible Connectible
		Name		Example
-------------------------------------------------------------------------

Yes	No	Unknown		(Invalid state.)

Yes	Yes	Hot-plug	USB ports on the outside of a laptop.
				A user could freely connect and disconnect
				USB devices.

No	Yes	Hard-wired	A USB modem hard-wired to a port on the
				inside of a laptop.

No	No	Not used	The port is internal to the system and
				will remain empty.

Represent each of these four states with an enum usb_port_connect_type.
The four states are USB_PORT_CONNECT_TYPE_UNKNOWN,
USB_PORT_CONNECT_TYPE_HOT_PLUG, USB_PORT_CONNECT_TYPE_HARD_WIRED, and
USB_PORT_NOT_USED.  When we get the USB port's acpi_handle, store the
state in connect_type in struct usb_port.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-10 13:04:01 -07:00
Lan Tianyu
ff823c79a5 usb: move children to struct usb_port
The usb_device structure contains an array of usb_device "children".
This array is only valid if the usb_device is a hub, so it makes no
sense to store it there.  Instead, store the usb_device child
in its parent usb_port structure.

Since usb_port is an internal USB core structure, add a new function to
get the USB device child, usb_hub_find_child().  Add a new macro,
usb_hub_get_each_child(), to iterate over all the children attached to a
particular USB hub.

Remove the printing the USB children array pointer from the usb-ip
driver, since it's really not necessary.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-10 12:59:42 -07:00
Gustavo Padovan
d81a5d1956 USB: add USB_VENDOR_AND_INTERFACE_INFO() macro
A lot of Broadcom Bluetooth devices provides vendor specific interface
class and we are getting flooded by patches adding new device support.
This change will help us enable support for any other Broadcom with vendor
specific device that arrives in the future.

Only the product id changes for those devices, so this macro would be
perfect for us:

{ USB_VENDOR_AND_INTERFACE_INFO(0x0a5c, 0xff, 0x01, 0x01) }

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Acked-by: Henrik Rydberg <rydberg@bitmath.se>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16 17:43:04 -07:00
Richard Kennedy
0d5ff30658 USB: remove 8 bytes of padding from usb_host_interface on 64 bit builds
Reorder elements in the usb_host_interface structure to remove 8 bytes
of padding on 64 bit builds , and so shrink it's size to 40 bytes.

usb_interface_descriptor is a odd size which leaves a gap that is not
big enough to hold a pointer, so moving extralen into that gap removes
the need for more padding.

Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16 17:21:29 -07:00
Sarah Sharp
024f117c2f USB: Add a sysfs file to show LTM capabilities.
USB 3.0 devices can optionally support Latency Tolerance Messaging
(LTM).  Add a new sysfs file in the device directory to show whether a
device is LTM capable.  This file will be present for both USB 2.0 and
USB 3.0 devices.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
2012-07-11 07:06:48 -04:00
Sarah Sharp
f74631e342 USB: Enable Latency Tolerance Messaging (LTM).
USB 3.0 devices may optionally support a new feature called Latency
Tolerance Messaging.  If both the xHCI host controller and the device
support LTM, it should be turned on in order to give the system hardware
a better clue about the latency tolerance values of its PCI devices.

Once a Set Feature request to enable LTM is received, the USB 3.0 device
will begin to send LTM updates as its buffers fill or empty, and it can
tolerate more or less latency.

The USB 3.0 spec, section C.4.2 says that LTM should be disabled just
before the device is placed into suspend.  Then the device will send an
updated LTM notification, so that the system doesn't think it should
remain in an active state in order to satisfy the latency requirements
of the suspended device.

The Set and Clear Feature LTM enable command can only be sent to a
configured device.  The device will respond with an error if that
command is sent while it is in the Default or Addressed state.  Make
sure to check udev->actconfig in usb_enable_ltm() and usb_disable_ltm(),
and don't send those commands when the device is unconfigured.

LTM should be enabled once a new configuration is installed in
usb_set_configuration().  If we end up sending duplicate Set Feature LTM
Enable commands on a switch from one installed configuration to another
configuration, that should be harmless.

Make sure that LTM is disabled before the device is unconfigured in
usb_disable_device().  If no drivers are bound to the device, it doesn't
make sense to allow the device to control the latency tolerance of the
xHCI host controller.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
2012-07-11 07:06:48 -04:00
Sarah Sharp
c5c4bdf02e USB: Remove unused LPM variable.
hub_initiated_lpm_disable_count is not used by any code, so remove it.

This commit should be backported to kernels as old as 3.5, that contain
the commit 8306095fd2 "USB: Disable USB
3.0 LPM in critical sections."

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org
2012-07-11 07:06:47 -04:00
Hans de Goede
19181bc50e usbdevfs: Add a USBDEVFS_GET_CAPABILITIES ioctl
There are a few (new) usbdevfs capabilities which an application cannot
discover in any other way then checking the kernel version. There are 3
problems with this:
1) It is just not very pretty.
2) Given the tendency of enterprise distros to backport stuff it is not
reliable.
3) As discussed in length on the mailinglist, USBDEVFS_URB_BULK_CONTINUATION
does not work as it should when combined with USBDEVFS_URB_SHORT_NOT_OK
(which is its intended use) on devices attached to an XHCI controller.
So the availability of these features can be host controller dependent,
making depending on them based on the kernel version not a good idea.

This patch besides adding the new ioctl also adds flags for the following
existing capabilities:

USBDEVFS_CAP_ZERO_PACKET,        available since 2.6.31
USBDEVFS_CAP_BULK_CONTINUATION,  available since 2.6.32, except for XHCI
USBDEVFS_CAP_NO_PACKET_SIZE_LIM, available since 3.3

Note that this patch only does not advertise the USBDEVFS_URB_BULK_CONTINUATION
cap for XHCI controllers, bulk transfers with this flag set will still be
accepted when submitted to XHCI controllers.

Returning -EINVAL for them would break existing apps, and in most cases the
troublesome scenario wrt USBDEVFS_URB_SHORT_NOT_OK urbs on XHCI controllers
will never get hit, so this would break working use cases.

The disadvantage of not returning -EINVAL is that cases were it is causing
real trouble may go undetected / the cause of the trouble may be unclear,
but this is the best we can do.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-06 10:53:19 -07:00
Bjørn Mork
81df2d5943 USB: allow match on bInterfaceNumber
Some composite USB devices provide multiple interfaces
with different functions, all using "vendor-specific"
for class/subclass/protocol.  Another OS use interface
numbers to match the driver and interface. It seems
these devices are designed with that in mind - using
static interface numbers for the different functions.

This adds support for matching against the
bInterfaceNumber, allowing such devices to be supported
without having to resort to testing against interface
number whitelists and/or blacklists in the probe.

Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13 15:40:09 -07:00
Sarah Sharp
e9261fb62a USB: Fix core compile with CONFIG_USB_SUSPEND=n
When CONFIG_PM=n, make sure that the usb_[unlocked_][en/dis]able_lpm
declarations are visible in include/linux/usb.h, and exported from
drivers/usb/core/hub.c.

Before this patch, if CONFIG_USB_SUSPEND was turned off, it would cause
build errors:

drivers/usb/core/hub.c: In function 'usb_disable_lpm':
drivers/usb/core/hub.c:3394:2: error: implicit declaration of function 'usb_enable_lpm' [-Werror=implicit-function-declaration]
drivers/usb/core/hub.c: At top level:
drivers/usb/core/hub.c:3424:6: warning: conflicting types for 'usb_enable_lpm' [enabled by default]
drivers/usb/core/hub.c:3394:2: note: previous implicit declaration of 'usb_enable_lpm' was here
drivers/usb/core/driver.c: In function 'usb_probe_interface':
drivers/usb/core/driver.c:339:2: error: implicit declaration of function 'usb_unlocked_disable_lpm' [-Werror=implicit-function-declaration]
drivers/usb/core/driver.c:364:3: error: implicit declaration of function 'usb_unlocked_enable_lpm' [-Werror=implicit-function-declaration]
drivers/usb/core/message.c: In function 'usb_set_interface':
drivers/usb/core/message.c:1314:2: error: implicit declaration of function 'usb_disable_lpm' [-Werror=implicit-function-declaration]
drivers/usb/core/message.c:1323:3: error: implicit declaration of function 'usb_enable_lpm' [-Werror=implicit-function-declaration]
drivers/usb/core/message.c:1368:2: error: implicit declaration of function 'usb_unlocked_enable_lpm' [-Werror=implicit-function-declaration]

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Chen Peter-B29397 <B29397@freescale.com>
2012-05-21 09:00:03 -07:00
Sarah Sharp
8306095fd2 USB: Disable USB 3.0 LPM in critical sections.
There are several places where the USB core needs to disable USB 3.0
Link PM:
 - usb_bind_interface
 - usb_unbind_interface
 - usb_driver_claim_interface
 - usb_port_suspend/usb_port_resume
 - usb_reset_and_verify_device
 - usb_set_interface
 - usb_reset_configuration
 - usb_set_configuration

Use the new LPM disable/enable functions to temporarily disable LPM
around these critical sections.

We need to protect the critical section around binding and unbinding USB
interface drivers.  USB drivers may want to disable hub-initiated USB
3.0 LPM, which will change the value of the U1/U2 timeouts that the xHCI
driver will install.  We need to disable LPM completely until the driver
is bound to the interface, and the driver has a chance to enable
whatever alternate interface setting it needs in its probe routine.
Then re-enable USB3 LPM, and recalculate the U1/U2 timeout values.

We also need to disable LPM in usb_driver_claim_interface,
because drivers like usbfs can bind to an interface through that
function.  Note, there is no way currently for userspace drivers to
disable hub-initiated USB 3.0 LPM.  Revisit this later.

When a driver is unbound, the U1/U2 timeouts may change because we are
unbinding the last driver that needed hub-initiated USB 3.0 LPM to be
disabled.

USB LPM must be disabled when a USB device is going to be suspended.
The USB 3.0 spec does not define a state transition from U1 or U2 into
U3, so we need to bring the device into U0 by disabling LPM before we
can place it into U3.  Therefore, call usb_unlocked_disable_lpm() in
usb_port_suspend(), and call usb_unlocked_enable_lpm() in
usb_port_resume().  If the port suspend fails, make sure to re-enable
LPM by calling usb_unlocked_enable_lpm(), since usb_port_resume() will
not be called on a failed port suspend.

USB 3.0 devices lose their USB 3.0 LPM settings (including whether USB
device-initiated LPM is enabled) across device suspend.  Therefore,
disable LPM before the device will be reset in
usb_reset_and_verify_device(), and re-enable LPM after the reset is
complete and the configuration/alt settings are re-installed.

The calculated U1/U2 timeout values are heavily dependent on what USB
device endpoints are currently enabled.  When any of the enabled
endpoints on the device might change, due to a new configuration, or new
alternate interface setting, we need to first disable USB 3.0 LPM, add
or delete endpoints from the xHCI schedule, install the new interfaces
and alt settings, and then re-enable LPM.  Do this in usb_set_interface,
usb_reset_configuration, and usb_set_configuration.

Basically, there is a call to disable and then enable LPM in all
functions that lock the bandwidth_mutex.  One exception is
usb_disable_device, because the device is disconnecting or otherwise
going away, and we should not care about whether USB 3.0 LPM is enabled.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
2012-05-18 15:41:59 -07:00
Sarah Sharp
1ea7e0e8e3 USB: Add support to enable/disable USB3 link states.
There are various functions within the USB core that will need to
disable USB 3.0 link power states.  For example, when a USB device
driver is being bound to an interface, we need to disable USB 3.0 LPM
until we know if the driver will allow hub-initiated LPM transitions.
Another example is when the USB core is switching alternate interface
settings.  The USB 3.0 timeout values are dependent on what endpoints
are enabled, so we want to ensure that LPM is disabled until the new alt
setting is fully installed.

Multiple functions need to disable LPM, and those functions can even be
nested.  For example, usb_bind_interface() could disable LPM, and then
call into the driver probe function, which may attempt to switch to a
different alt setting.  Therefore, we need to keep a count of the number
of functions that require LPM to be disabled at any point in time.

Introduce two new USB core API calls, usb_disable_lpm() and
usb_enable_lpm().  These functions increment and decrement a new
variable in the usb_device, lpm_disable_count.  If usb_disable_lpm()
fails, it will call usb_enable_lpm() in order to balance the
lpm_disable_count.

These two new functions must be called with the bandwidth_mutex locked.
If the bandwidth_mutex is not already held by the caller, it should
instead call usb_unlocked_disable_lpm() and usb_enable_lpm(), which take
the bandwidth_mutex before calling usb_disable_lpm() and
usb_enable_lpm(), respectively.

Introduce a new variable (timeout) in the usb3_lpm_params structure to
keep track of the currently enabled U1/U2 timeout values.  When
usb_disable_lpm() is called, and the USB device has the U1 or U2
timeouts set to a non-zero value (meaning either device-initiated or
hub-initiated LPM is enabled), attempt to disable LPM, regardless of the
state of the lpm_disable_count.  We want to ensure that all callers can
be guaranteed that LPM is disabled if usb_disable_lpm() returns zero.

Otherwise the following scenario could occur:

1. Driver A is being bound to interface 1.  usb_probe_interface()
disables LPM.  Driver A doesn't care if hub-initiated LPM is enabled, so
even though usb_disable_lpm() fails, the probe of the driver continues,
and the bandwidth mutex is dropped.

2. Meanwhile, Driver B is being bound to interface 2.
usb_probe_interface() grabs the bandwidth mutex and calls
usb_disable_lpm().  That call should attempt to disable LPM, even
though the lpm_disable_count is set to 1 by Driver A.

For usb_enable_lpm(), we attempt to enable LPM only when the
lpm_disable_count is zero.  If some step in enabling LPM fails, it will
only have a minimal impact on power consumption, and all USB device
drivers should still work properly.  Therefore don't bother to return
any error codes.

Don't enable device-initiated LPM if the device is unconfigured.  The
USB device will only accept the U1/U2_ENABLE control transfers in the
configured state.  Do enable hub-initiated LPM in that case, since
devices are allowed to accept the LGO_Ux link commands in any state.

Don't enable or disable LPM if the device is marked as not being LPM
capable.  This can happen if:
 - the USB device doesn't have a SS BOS descriptor,
 - the device's parent hub has a zeroed bHeaderDecodeLatency value, or
 - the xHCI host doesn't support LPM.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Andiry Xu <andiry.xu@amd.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
2012-05-18 15:41:58 -07:00
Sarah Sharp
8afa408cba USB: Allow drivers to disable hub-initiated LPM.
USB 3.0 Link Power Management (LPM) is designed to allow individual
links in the bus to go into lower power states.  There are two ways a
link can enter a lower power state:

1. Device-initiated LPM.  When a USB device decides it can go into a
lower power link state, it sends a message to the parent hub, telling it
to go into either U1 or U2.  Device-initiated LPM is good for devices
that send data to the host, like communications devices.

2. Hub-initiated LPM.  After the link has been idle for a specific
amount of time, the parent hub will request that the child go into a
lower power state.  The child can refuse that request.  For example, a
USB modem may want to refuse the LPM request if it is in the middle of
receiving a text message.  Hub-initiated LPM is good for devices where
only the host initiates the data transfer, like USB printers or USB mass
storage devices.

Links will be automatically placed into higher power states by the USB
hubs and roothubs whenever the host starts a USB transmission.

Introduce a new usb_driver flag, disable_hub_initiated_lpm, that allows
drivers to disable hub-initiated LPM.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Hansjoerg Lipp <hjlipp@web.de>
Cc: Tilman Schmidt <tilman@imap.cc>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Oliver Neukum <oliver@neukum.name>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Cc: Jan Dumon <j.dumon@option.com>
Cc: Petko Manolov <petkan@users.sourceforge.net>
Cc: Steve Glendinning <steve.glendinning@smsc.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: Kalle Valo <kvalo@qca.qualcomm.com>
Cc: "Luis R. Rodriguez" <mcgrof@qca.qualcomm.com>
Cc: Jouni Malinen <jouni@qca.qualcomm.com>
Cc: Vasanthakumar Thiagarajan <vthiagar@qca.qualcomm.com>
Cc: Senthil Balasubramanian <senthilb@qca.qualcomm.com>
Cc: Christian Lamparter <chunkeey@googlemail.com>
Cc: Brett Rudley <brudley@broadcom.com>
Cc: Roland Vossen <rvossen@broadcom.com>
Cc: Arend van Spriel <arend@broadcom.com>
Cc: "Franky (Zhenhui) Lin" <frankyl@broadcom.com>
Cc: Kan Yan <kanyan@broadcom.com>
Cc: Dan Williams <dcbw@redhat.com>
Cc: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Cc: Ivo van Doorn <IvDoorn@gmail.com>
Cc: Gertjan van Wingerde <gwingerde@gmail.com>
Cc: Helmut Schaa <helmut.schaa@googlemail.com>
Cc: Herton Ronaldo Krzesinski <herton@canonical.com>
Cc: Hin-Tak Leung <htl10@users.sourceforge.net>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Chaoming Li <chaoming_li@realsil.com.cn>
Cc: Daniel Drake <dsd@gentoo.org>
Cc: Ulrich Kunitz <kune@deine-taler.de>
Cc: linux-bluetooth@vger.kernel.org
Cc: gigaset307x-common@lists.sourceforge.net
Cc: netdev@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Cc: linux-wireless@vger.kernel.org
Cc: ath9k-devel@lists.ath9k.org
Cc: libertas-dev@lists.infradead.org
Cc: users@rt2x00.serialmonkey.com
2012-05-18 15:41:57 -07:00
Sarah Sharp
51e0a01206 USB: Calculate USB 3.0 exit latencies for LPM.
There are several different exit latencies associated with coming out of
the U1 or U2 lower power link state.

Device Exit Latency (DEL) is the maximum time it takes for the USB
device to bring its upstream link into U0.  That can be found in the
SuperSpeed Extended Capabilities BOS descriptor for the device.  The
time it takes for a particular link in the tree to exit to U0 is the
maximum of either the parent hub's U1/U2 DEL, or the child's U1/U2 DEL.

Hubs introduce a further delay that effects how long it takes a child
device to transition to U0.  When a USB 3.0 hub receives a header
packet, it takes some time to decode that header and figure out which
downstream port the packet was destined for.  If the port is not in U0,
this hub header decode latency will cause an additional delay for
bringing the child device to U0.  This Hub Header Decode Latency is
found in the USB 3.0 hub descriptor.

We can use DEL and the header decode latency, along with additional
latencies imposed by each additional hub tier, to figure out the exit
latencies for both host-initiated and device-initiated exit to U0.

The Max Exit Latency (MEL) is the worst-case time it will take for a
host-initiated exit to U0, based on whether U1 or U2 link states are
enabled.  The ping or packet must traverse the path to the device, and
each hub along the way incurs the hub header decode latency in order to
figure out which device the transfer was bound for.  We say worst-case,
because some hubs may not be in the lowest link state that is enabled.
See the examples in section C.2.2.1.

Note that "HSD" is a "host specific delay" that the power appendix
architect has not been able to tell me how to calculate.  There's no way
to get HSD from the xHCI registers either, so I'm simply ignoring it.

The Path Exit Latency (PEL) is the worst-case time it will take for a
device-initiate exit to U0 to place all the links from the device to the
host into U0.

The System Exit Latency (SEL) is another device-initiated exit latency.
SEL is useful for USB 3.0 devices that need to send data to the host at
specific intervals.  The device may send an NRDY to indicate it isn't
ready to send data, then put its link into a lower power state.  If it
needs to have that data transmitted at a specific time, it can use SEL
to back calculate when it will need to bring the link back into U0 to
meet its deadlines.

SEL is the worst-case time from the device-initiated exit to U0, to when
the device will receive a packet from the host controller.  It includes
PEL, the time it takes for an ERDY to get to the host, a host-specific
delay for the host to process that ERDY, and the time it takes for the
packet to traverse the path to the device.  See Figure C-2 in the USB
3.0 bus specification.

Note: I have not been able to get good answers about what the
host-specific delay to process the ERDY should be.  The Intel HW
developers say it will be specific to the platform the xHCI host is
integrated into, and they say it's negligible.  Ignore this too.

Separate from these four exit latencies are the U1/U2 timeout values we
program into the parent hubs.  These timeouts tell the hub to attempt to
place the device into a lower power link state after the link has been
idle for that amount of time.

Create two arrays (one for U1 and one for U2) to store mel, pel, sel,
and the timeout values.  Store the exit latency values in nanosecond
units, since that's the smallest units used (DEL is in us, but the Hub
Header Decode Latency is in ns).

If a USB 3.0 device doesn't have a SuperSpeed Extended Capabilities BOS
descriptor, it's highly unlikely it will be able to handle LPM requests
properly.  So it's best to disable LPM for devices that don't have this
descriptor, and any children beneath it, if it's a USB 3.0 hub.  Warn
users when that happens, since it means they have a non-compliant USB
3.0 device or hub.

This patch assumes a simplified design where links deep in the tree will
not have U1 or U2 enabled unless all their parent links have the
corresponding LPM state enabled.  Eventually, we might want to allow a
different policy, and we can revisit this patch when that happens.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
2012-05-18 15:41:56 -07:00
Bjørn Mork
ef206f3f01 USB: add read support to usb-serial/../new_id
Keep the usb-serial support for dynamic IDs in sync with the usb
support.  This enables readout of dynamic device IDs for
usb-serial drivers.  Common code is exported from the usb core
system and reused by the usb-serial bus driver.

Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-14 09:30:40 -07:00
Greg Kroah-Hartman
fa286188ce Revert "usb: move struct usb_device->children to struct usb_hub_port->child"
This reverts commit bebc56d58d.

The call here is fragile and not well thought out, so revert it, it's
not fully baked yet and I don't want this to go into 3.5.

Cc: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-14 09:20:37 -07:00
Lan Tianyu
bebc56d58d usb: move struct usb_device->children to struct usb_hub_port->child
Move child's pointer to the struct usb_hub_port since the child device
is directly associated with the port. Provide usb_get_hub_child_device()
to get child's pointer.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-11 17:08:41 -07:00
Oliver Neukum
8815bb09af usbhid: prevent deadlock during timeout
On some HCDs usb_unlink_urb() can directly call the
completion handler. That limits the spinlocks that can
be taken in the handler to locks not held while calling
usb_unlink_urb()
To prevent a race with resubmission, this patch exposes
usbcore's infrastructure for blocking submission, uses it
and so drops the lock without causing a race in usbhid.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-01 13:22:13 -04:00
Greg Kroah-Hartman
007bab9132 USB: remove CONFIG_USB_DEVICE_CLASS
This option has been deprecated for many years now, and no userspace
tools use it anymore, so it should be safe to finally remove it.

Reported-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-29 22:29:57 -04:00
Greg Kroah-Hartman
fb28d58b72 USB: remove CONFIG_USB_DEVICEFS
This option has been deprecated for many years now, and no userspace
tools use it anymore, so it should be safe to finally remove it.

Reported-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-29 22:20:03 -04:00
Greg Kroah-Hartman
af4e1ee040 USB: remove err() macro
I thought this had been removed years ago.  All in-kernel users of this
call have now been cleaned up and converted over to use dev_err()
instead, which is the correct thing to do.  Now that there are no users,
the macro can be removed so no one else accidentally starts to use it.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-25 14:55:16 -07:00
Johan Hovold
67c88382e0 USB: add EOPNOTSUPP to usb_translate_errors
Allow drivers to return EOPNOTSUPP to user space even when filtered
through usb_translate_errors.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-18 13:46:41 -07:00
Huajun Li
8816230e13 USB: dynamically allocate usb_device children pointers instead of using a fix array
Non-hub device has no child, and even a real USB hub has ports far
less than USB_MAXCHILDREN, so there is no need using a fix array for
child devices, just allocate it dynamically according real port
number.

Signed-off-by: Huajun Li <huajun.li.lee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-13 14:24:07 -07:00
Greg Kroah-Hartman
7483948fdd Merge tag 'usb-3.3-rc3' into usb-next
This is done to resolve a merge conflict with:
	drivers/usb/class/cdc-wdm.c
and to better handle future patches for this driver as it is under
active development at the moment.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-02-10 11:13:53 -08:00
Matthew Garrett
0846e7e985 usb: Add support for indicating whether a port is removable
Userspace may want to make policy decisions based on whether or not a
given USB device is removable. Add a per-device member and support
for exposing it in sysfs. Information sources to populate it will be
added later.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-02-09 08:40:11 -08:00
Randy Dunlap
4d922612df kernel-doc: fix new warning in usb.h
Fix new kernel-doc warning:

Warning(include/linux/usb.h:1251): No description found for parameter 'num_mapped_sgs'

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-23 08:44:54 -08:00
Linus Torvalds
55b81e6f27 Merge branch 'usb-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
* 'usb-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (232 commits)
  USB: Add USB-ID for Multiplex RC serial adapter to cp210x.c
  xhci: Clean up 32-bit build warnings.
  USB: update documentation for usbmon
  usb: usb-storage doesn't support dynamic id currently, the patch disables the feature to fix an oops
  drivers/usb/class/cdc-acm.c: clear dangling pointer
  drivers/usb/dwc3/dwc3-pci.c: introduce missing kfree
  drivers/usb/host/isp1760-if.c: introduce missing kfree
  usb: option: add ZD Incorporated HSPA modem
  usb: ch9: fix up MaxStreams helper
  USB: usb-skeleton.c: cleanup open_count
  USB: usb-skeleton.c: fix open/disconnect race
  xhci: Properly handle COMP_2ND_BW_ERR
  USB: remove dead code from suspend/resume path
  USB: add quirk for another camera
  drivers: usb: wusbcore: Fix dependency for USB_WUSB
  xhci: Better debugging for critical host errors.
  xhci: Be less verbose during URB cancellation.
  xhci: Remove debugging about ring structure allocation.
  xhci: Remove debugging about toggling cycle bits.
  xhci: Remove debugging for individual transfers.
  ...
2012-01-09 12:09:47 -08:00
Linus Torvalds
972b2c7199 Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
* 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (165 commits)
  reiserfs: Properly display mount options in /proc/mounts
  vfs: prevent remount read-only if pending removes
  vfs: count unlinked inodes
  vfs: protect remounting superblock read-only
  vfs: keep list of mounts for each superblock
  vfs: switch ->show_options() to struct dentry *
  vfs: switch ->show_path() to struct dentry *
  vfs: switch ->show_devname() to struct dentry *
  vfs: switch ->show_stats to struct dentry *
  switch security_path_chmod() to struct path *
  vfs: prefer ->dentry->d_sb to ->mnt->mnt_sb
  vfs: trim includes a bit
  switch mnt_namespace ->root to struct mount
  vfs: take /proc/*/mounts and friends to fs/proc_namespace.c
  vfs: opencode mntget() mnt_set_mountpoint()
  vfs: spread struct mount - remaining argument of next_mnt()
  vfs: move fsnotify junk to struct mount
  vfs: move mnt_devname
  vfs: move mnt_list to struct mount
  vfs: switch pnode.h macros to struct mount *
  ...
2012-01-08 12:19:57 -08:00
Al Viro
2c9ede55ec switch device_get_devnode() and ->devnode() to umode_t *
both callers of device_get_devnode() are only interested in lower 16bits
and nobody tries to return anything wider than 16bit anyway.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:54:55 -05:00
Clemens Ladisch
bc677d5b64 usb: fix number of mapped SG DMA entries
Add a new field num_mapped_sgs to struct urb so that we have a place to
store the number of mapped entries and can also retain the original
value of entries in num_sgs.  Previously, usb_hcd_map_urb_for_dma()
would overwrite this with the number of mapped entries, which would
break dma_unmap_sg() because it requires the original number of entries.

This fixes warnings like the following when using USB storage devices:
 ------------[ cut here ]------------
 WARNING: at lib/dma-debug.c:902 check_unmap+0x4e4/0x695()
 ehci_hcd 0000:00:12.2: DMA-API: device driver frees DMA sg list with different entry count [map count=4] [unmap count=1]
 Modules linked in: ohci_hcd ehci_hcd
 Pid: 0, comm: kworker/0:1 Not tainted 3.2.0-rc2+ #319
 Call Trace:
  <IRQ>  [<ffffffff81036d3b>] warn_slowpath_common+0x80/0x98
  [<ffffffff81036de7>] warn_slowpath_fmt+0x41/0x43
  [<ffffffff811fa5ae>] check_unmap+0x4e4/0x695
  [<ffffffff8105e92c>] ? trace_hardirqs_off+0xd/0xf
  [<ffffffff8147208b>] ? _raw_spin_unlock_irqrestore+0x33/0x50
  [<ffffffff811fa84a>] debug_dma_unmap_sg+0xeb/0x117
  [<ffffffff8137b02f>] usb_hcd_unmap_urb_for_dma+0x71/0x188
  [<ffffffff8137b166>] unmap_urb_for_dma+0x20/0x22
  [<ffffffff8137b1c5>] usb_hcd_giveback_urb+0x5d/0xc0
  [<ffffffffa0000d02>] ehci_urb_done+0xf7/0x10c [ehci_hcd]
  [<ffffffffa0001140>] qh_completions+0x429/0x4bd [ehci_hcd]
  [<ffffffffa000340a>] ehci_work+0x95/0x9c0 [ehci_hcd]
  ...
 ---[ end trace f29ac88a5a48c580 ]---
 Mapped at:
  [<ffffffff811faac4>] debug_dma_map_sg+0x45/0x139
  [<ffffffff8137bc0b>] usb_hcd_map_urb_for_dma+0x22e/0x478
  [<ffffffff8137c494>] usb_hcd_submit_urb+0x63f/0x6fa
  [<ffffffff8137d01c>] usb_submit_urb+0x2c7/0x2de
  [<ffffffff8137dcd4>] usb_sg_wait+0x55/0x161

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-12-09 16:18:19 -08:00
Greg Kroah-Hartman
f3a6a4b6cf USB: Add helper macro for usb_driver boilerplate
This patch introduces the module_usb_driver macro which is a convenience
macro for USB driver modules similar to module_platform_driver. It is
intended to be used by drivers which init/exit section does nothing but
register/unregister the USB driver. By using this macro it is possible
to eliminate a few lines of boilerplate code per USB driver.

Based on work done by Lars-Peter Clausen <lars@metafoo.de> for other
busses (i2c and spi).

Cc: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-11-17 14:38:33 -08:00
Johan Hovold
2c4d6bf295 USB: move usb_translate_errors to linux/usb.h
Move usb_translate_errors from usb core to linux/usb.h as it is meant to
be accessed from drivers.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-11-15 10:47:40 -08:00
Paul Gortmaker
eb5589a8f0 include: convert various register fcns to macros to avoid include chaining
The original implementations reference THIS_MODULE in an inline.
We could include <linux/export.h>, but it is better to avoid chaining.

Fortunately someone else already thought of this, and made a similar
inline into a #define in <linux/device.h> for device_schedule_callback(),
[see commit 523ded71de] so follow that precedent here.

Also bubble up any __must_check that were used on the prev. wrapper inline
functions up one to the real __register functions, to preserve any prev.
sanity checks that were used in those instances.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:32:32 -04:00
Andiry Xu
65580b4321 xHCI: set USB2 hardware LPM
If the device pass the USB2 software LPM and the host supports hardware
LPM, enable hardware LPM for the device to let the host decide when to
put the link into lower power state.

If hardware LPM is enabled for a port and driver wants to put it into
suspend, it must first disable hardware LPM, resume the port into U0,
and then suspend the port.

Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-09-26 15:51:10 -07:00
Andiry Xu
1ff4df5684 usbcore: check device's LPM capability
Check device's LPM capability by examining the bmAttibutes field of the
USB2.0 Extension Descriptor.

Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-09-26 15:51:08 -07:00
Andiry Xu
3148bf041d usbcore: get BOS descriptor set
This commit gets BOS(Binary Device Object Store) descriptor set for Super
Speed devices and High Speed devices which support BOS descriptor.

BOS descriptor is used to report additional USB device-level capabilities
that are not reported via the Device descriptor. By getting BOS descriptor
set, driver can check device's device-level capability such as LPM
capability.

Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-09-26 15:51:08 -07:00
Kuninori Morimoto
29cc88979a USB: use usb_endpoint_maxp() instead of le16_to_cpu()
Now ${LINUX}/drivers/usb/* can use usb_endpoint_maxp(desc) to get maximum packet size
instead of le16_to_cpu(desc->wMaxPacketSize).
This patch fix it up

Cc: Armin Fuerst <fuerst@in.tum.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Johannes Erdfelt <johannes@erdfelt.com>
Cc: Vojtech Pavlik <vojtech@suse.cz>
Cc: Oliver Neukum <oliver@neukum.name>
Cc: David Kubicek <dave@awk.cz>
Cc: Johan Hovold <jhovold@gmail.com>
Cc: Brad Hards <bhards@bigpond.net.au>
Acked-by: Felipe Balbi <balbi@ti.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Dahlmann <dahlmann.thomas@arcor.de>
Cc: David Brownell <david-b@pacbell.net>
Cc: David Lopo <dlopo@chipidea.mips.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Michal Nazarewicz <m.nazarewicz@samsung.com>
Cc: Xie Xiaobo <X.Xie@freescale.com>
Cc: Li Yang <leoli@freescale.com>
Cc: Jiang Bo <tanya.jiang@freescale.com>
Cc: Yuan-hsin Chen <yhchen@faraday-tech.com>
Cc: Darius Augulis <augulis.darius@gmail.com>
Cc: Xiaochen Shen <xiaochen.shen@intel.com>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: OKI SEMICONDUCTOR, <toshiharu-linux@dsn.okisemi.com>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Ben Dooks <ben@simtec.co.uk>
Cc: Thomas Abraham <thomas.ab@samsung.com>
Cc: Herbert Pötzl <herbert@13thfloor.at>
Cc: Arnaud Patard <arnaud.patard@rtp-net.org>
Cc: Roman Weissgaerber <weissg@vienna.at>
Acked-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Tony Olech <tony.olech@elandigitalsystems.com>
Cc: Florian Floe Echtler <echtler@fs.tum.de>
Cc: Christian Lucht <lucht@codemercs.com>
Cc: Juergen Stuber <starblue@sourceforge.net>
Cc: Georges Toth <g.toth@e-biz.lu>
Cc: Bill Ryder <bryder@sgi.com>
Cc: Kuba Ober <kuba@mareimbrium.org>
Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-23 09:47:40 -07:00
Alan Stern
6498d9db6d USB: documentation update for the pre_reset method
This patch (as1459) updates the documentation for the pre_reset method
in struct usb_driver.  When a driver is notified of an impending
reset, it must cancel all outstanding I/O and not start any new I/O
until it has been notified that the reset is complete.

As far as I know, most existing drivers that implement pre_reset do
this now.  The major exceptions appear to be the SpeedTouch and
CDC-WDM drivers.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-29 17:24:29 -07:00
Lucas De Marchi
25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Robert Morell
2694a48d90 USB: HCD: Add driver hooks for (un)?map_urb_for_dma
Provide optional hooks for the host controller driver to override the
default DMA mapping and unmapping routines.  In general, these shouldn't
be necessary unless the host controller has special DMA requirements,
such as alignment contraints.  If these are not specified, the
general usb_hcd_(un)?map_urb_for_dma functions will be used instead.
Also, pass the status to unmap_urb_for_dma so it can know whether the
DMA buffer has been overwritten.

Finally, add a flag to be used by these implementations if they
allocated a temporary buffer so it can be freed properly when unmapping.

Signed-off-by: Robert Morell <rmorell@nvidia.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-04 11:48:55 -08:00