Sometimes, the gadget driver we want to run has max_speed lower than
what the UDC supports. In such situations, UDC might want to make sure
we don't try to connect on speeds not supported by the gadget
driver (e.g. super-speed capable dwc3 with high-speed capable g_midi)
because that will just fail.

In order to make sure this situation never happens, we introduce a new
optional ->udc_set_speed() method which can be implemented by
interested UDC drivers.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

This commit allows a gadget that does not support SuperSpeed to indicate
that it supports LPM. It does this by setting the 'lpm_capable' flag in
the gadget structure.

If a gadget sets this, the composite gadget framework will set the
bcdUSB to 0x0201 to indicate that this supports BOS descriptors, and
also return a USB 2.0 Extension descriptor as part of the BOS descriptor
set.

See USB 2.0 LPM ECN Section 3.
Signed-off-by: NJohn Youn <johnyoun@synopsys.com>
Signed-off-by: NSevak Arakelyan <sevaka@synopsys.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Usually usb phy need register one extcon device to get the connection
notifications. It will remove some duplicate code if the extcon device
is registered using common code instead of each phy driver having its
own related extcon APIs. So we add one pointer of extcon device into
usb phy structure, and some other helper functions to register extcon.
Signed-off-by: NBaolin Wang <baolin.wang@linaro.org>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

There's one value that use spaces instead of tabs to ident.
That causes the following warning:

./include/linux/usb/gadget.h:193: ERROR: Unexpected indentation.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

By definition, we use /* private: */ tag when we won't be documenting
a parameter. However, those two parameters are documented:

./include/linux/usb/composite.h:510: warning: Excess struct/union/enum/typedef member 'setup_pending' description in 'usb_composite_dev'
./include/linux/usb/composite.h:510: warning: Excess struct/union/enum/typedef member 'os_desc_pending' description in 'usb_composite_dev'

So, we need to use /* public: */ to avoid a warning.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

We need an space before a numbered list to avoid those warnings:

./drivers/usb/core/message.c:478: ERROR: Unexpected indentation.
./drivers/usb/core/message.c:479: WARNING: Block quote ends without a blank line; unexpected unindent.
./include/linux/usb/composite.h:455: ERROR: Unexpected indentation.
./include/linux/usb/composite.h:456: WARNING: Block quote ends without a blank line; unexpected unindent.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

If usb/otg-fsm.h and usb/composite.h are included together
then it results in the build warning [1].

Prevent that by defining VDBG locally.

Also get rid of MPC_LOC which doesn't seem to be used
by anyone.

[1] - warning fixed by this patch:

In file included from drivers/usb/dwc3/core.h:33,
   from drivers/usb/dwc3/ep0.c:33:
   include/linux/usb/otg-fsm.h:30:1: warning: "VDBG" redefined
   In file included from drivers/usb/dwc3/ep0.c:31:
   include/linux/usb/composite.h:615:1: warning: this is the location
   of the previous definition
Signed-off-by: NRoger Quadros <rogerq@ti.com>
Reviewed-by: NJun Li <jun.li@nxp.com>
Acked-by: NPeter Chen <peter.chen@nxp.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Add support for the net stats64 counters to the usbnet core. With that
in place put the hooks into every usbnet driver to use it.

This is a strait forward addition of 64bit counters for RX and TX packet
and byte counts. It is done in the same style as for the other net drivers
that support stats64. Note that the other stats fields remain as 32bit
sized values (error counts, etc).

The motivation to add this is that it is not particularly difficult to
get the RX and TX byte counts to wrap on 32bit platforms.
Signed-off-by: NGreg Ungerer <gerg@linux-m68k.org>
Acked-by: NBjørn Mork <bjorn@mork.no>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a calc_num_ports callback to the generic driver and verify that the
device has the required endpoints there instead of in core.

Note that the generic driver num_ports field was never used.
Signed-off-by: NJohan Hovold <johan@kernel.org>

Allow subdrivers to modify the port-endpoint mapping by passing the
endpoint descriptors to calc_num_ports.

The callback can now also be used to verify that the required endpoints
exists and abort probing otherwise.

This will allow us to get rid of a few hacks in subdrivers that are
already modifying the port-endpoint mapping (or aborting probe due to
missing endpoints), but only after the port structures have been setup.
Signed-off-by: NJohan Hovold <johan@kernel.org>

The purpose of USB Type-C connector class is to provide
unified interface for the user space to get the status and
basic information about USB Type-C connectors on a system,
control over data role swapping, and when the port supports
USB Power Delivery, also control over power role swapping
and Alternate Modes.
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-and-Tested-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Tested-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For xhci-hcd platform device, all the DMA parameters are not
configured properly, notably dma ops for dwc3 devices.

The idea here is that you pass in the parent of_node along with
the child device pointer, so it would behave exactly like the
parent already does. The difference is that it also handles all
the other attributes besides the mask.

sysdev will represent the physical device, as seen from firmware
or bus.Splitting the usb_bus->controller field into the
Linux-internal device (used for the sysfs hierarchy, for printks
and for power management) and a new pointer (used for DMA,
DT enumeration and phy lookup) probably covers all that we really
need.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NSriram Dash <sriram.dash@nxp.com>
Tested-by: NBaolin Wang <baolin.wang@linaro.org>
Tested-by: NBrian Norris <briannorris@chromium.org>
Tested-by: NAlexander Sverdlin <alexander.sverdlin@nokia.com>
Tested-by: NVivek Gautam <vivek.gautam@codeaurora.org>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NPeter Chen <peter.chen@nxp.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Sinjan Kumar <sinjank@codeaurora.org>
Cc: David Fisher <david.fisher1@synopsys.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "Thang Q. Nguyen" <tqnguyen@apm.com>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Dann Frazier <dann.frazier@canonical.com>
Cc: Peter Chen <peter.chen@nxp.com>
Cc: Leo Li <pku.leo@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The function usbnet_{get|set}_settings is no longer used,
so we remove it.
Signed-off-by: NPhilippe Reynes <tremyfr@gmail.com>
Acked-by: NOliver Neukum <oneukum@suse.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ethtool api {get|set}_settings is deprecated.
We add the new api {get|set}_link_ksettings to this driver.

As I don't have the hardware, I'd be very pleased if
someone may test this patch.
Signed-off-by: NPhilippe Reynes <tremyfr@gmail.com>
Acked-by: NOliver Neukum <oneukum@suse.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

XHCI debug capability (DbC) is an optional but standalone
functionality provided by an xHCI host controller. Software
learns this capability by walking through the extended
capability list of the host. XHCI specification describes
DbC in section 7.6.

This patch introduces the code to probe and initialize the
debug capability hardware during early boot. With hardware
initialized, the debug target (system on which this code is
running) will present a debug device through the debug port
(normally the first USB3 port). The debug device is fully
compliant with the USB framework and provides the equivalent
of a very high performance (USB3) full-duplex serial link
between the debug host and target. The DbC functionality is
independent of the xHCI host. There isn't any precondition
from the xHCI host side for the DbC to work.

One use for this feature is kernel debugging, for example
when your machine crashes very early before the regular
console code is initialized. Other uses include simpler,
lockless logging instead of a full-blown printk console
driver and klogd.
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-usb@vger.kernel.org
Link: http://lkml.kernel.org/r/1490083293-3792-3-git-send-email-baolu.lu@linux.intel.com
[ Small fix to the Kconfig help text. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>

EHCI controllers will have a companion controller. However, on platform
bus, there was difficult to bind them in previous code. So, this
patch adds helper functions to bind them using a "companion" property.
Signed-off-by: NYoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

a lot of embeded system SOC (e.g. freescale T2080) have both
PCI and USB modules. But USB module is controlled by registers directly,
it have no relationship with PCI module.

when say N here it will not build PCI related code in USB driver.
Signed-off-by: Nyuan linyu <Linyu.Yuan@alcatel-sbell.com.cn>
Acked-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Allow drivers to specify a minimum number of endpoints per type, which
USB serial core will verify after subdriver probe has returned (where
the current alternate setting may have been changed).
Signed-off-by: NJohan Hovold <johan@kernel.org>

Raise the arbitrary limit of how many ports a single device can claim
from eight to 16.

This specifically enables the upper eight ports of some mxuport devices.
Signed-off-by: NJohan Hovold <johan@kernel.org>

Use unsigned-char type for the endpoint and port counters.
Signed-off-by: NJohan Hovold <johan@kernel.org>

Some USB 2.0 devices erroneously report millisecond values in
bInterval. The generic config code manages to catch most of them,
but in some cases it's not completely enough.

The case at stake here is a USB 2.0 braille device, which wants to
announce 10ms and thus sets bInterval to 10, but with the USB 2.0
computation that yields to 64ms.  It happens that one can type fast
enough to reach this interval and get the device buffers overflown,
leading to problematic latencies.  The generic config code does not
catch this case because the 64ms is considered a sane enough value.

This change thus adds a USB_QUIRK_LINEAR_FRAME_INTR_BINTERVAL quirk
to mark devices which actually report milliseconds in bInterval,
and marks Vario Ultra devices as needing it.
Signed-off-by: NSamuel Thibault <samuel.thibault@ens-lyon.org>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The ULPI phy on qcom platforms needs to be initialized and
powered on after a USB reset and before we toggle the run/stop
bit. Otherwise, the phy locks up and doesn't work properly. Hook
the phy initialization into the RESET event and the phy power off
into the STOPPED event.
Acked-by: NPeter Chen <peter.chen@nxp.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NStephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: NPeter Chen <peter.chen@nxp.com>

The two extcon notifiers are almost the same except for the
variable name for the cable structure and the id notifier inverts
the cable->state logic. Make it the same and replace two
functions with one to save some lines. This also makes it so that
the id cable state is true when the id pin is pulled low, so we
change the name of ->state to ->connected to properly reflect
that we're interested in the cable being connected.
Acked-by: NPeter Chen <peter.chen@nxp.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Ivan T. Ivanov" <iivanov.xz@gmail.com>
Signed-off-by: NStephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: NPeter Chen <peter.chen@nxp.com>

The ULPI phy on qcom platforms needs to be initialized and
powered on after a USB reset and before we toggle the run/stop
bit. Otherwise, the phy locks up and doesn't work properly.
Therefore, add a flag to skip any phy power management in the
core layer, leaving it up to the glue driver to manage.
Acked-by: NPeter Chen <peter.chen@nxp.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NStephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: NPeter Chen <peter.chen@nxp.com>

We're currently emulating the vbus and id interrupts in the OTGSC
read API, but we also need to make sure that if we're handling
the events with extcon that we don't enable the interrupts for
those events in the hardware. Therefore, properly emulate this
register if we're using extcon, but don't enable the interrupts.
This allows me to get my cable connect/disconnect working
properly without getting spurious interrupts on my device that
uses an extcon for these two events.
Acked-by: NPeter Chen <peter.chen@nxp.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Ivan T. Ivanov" <iivanov.xz@gmail.com>
Fixes: 3ecb3e09 ("usb: chipidea: Use extcon framework for VBUS and ID detect")
Signed-off-by: NStephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: NPeter Chen <peter.chen@nxp.com>

Telit LE922A MBIM based composition does not work properly
with altsetting toggle done in cdc_ncm_bind_common.

This patch adds CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE quirk
to avoid this procedure that, instead, is mandatory for
other modems.
Signed-off-by: NDaniele Palmas <dnlplm@gmail.com>
Reviewed-by: NBjørn Mork <bjorn@mork.no>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, each hub class request constant is defined by a line like:
#define ClearHubFeature		(0x2000 | USB_REQ_CLEAR_FEATURE)

The "magic" number for the high byte is one of 0x20, 0xa0, 0x23, 0xa3.
The 0x80 bit that changes inditace USB_DIR_IN, and the 0x03 that
pops up is the difference between USB_RECIP_DEVICE (0x00) and
USB_RECIP_OTHER (0x03). The constant 0x20 bit is USB_TYPE_CLASS.

This patch eliminates those magic numbers by defining a macro to help
construct these hub class request from simpler constants.
Note that USB_RT_HUB is defined as (USB_TYPE_CLASS | USB_RECIP_DEVICE)
and that USB_RT_PORT is defined as (USB_TYPE_CLASS | USB_RECIP_OTHER).
Signed-off-by: NTal Shorer <tal.shorer@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For isoc endpoint descriptor, the wMaxPacketSize is not real max packet
size (see Table 9-13. Standard Endpoint Descriptor, USB 2.0 specifcation),
it may contain the number of packet, so the real max packet should be
ep->desc->wMaxPacketSize && 0x7ff.

Cc: Felipe F. Tonello <eu@felipetonello.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Fixes: 16b114a6 ("usb: gadget: fix usb_ep_align_maybe
  endianness and new usb_ep_aligna")
Signed-off-by: NPeter Chen <peter.chen@nxp.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Some platforms (e.g. USB-DMAC on R-Car SoCs) has memory alignment
restriction. If memory alignment is not match, the usb peripheral
driver decides not to use the DMA controller. Then, the performance
is not good.

In the case of u_ether.c, since it calls skb_reserve() in rx_submit(),
it is possible to cause memory alignment mismatch.

So, this patch adds a new quirk "quirk_avoids_skb_reserve" to avoid
skb_reserve() calling in u_ether.c to improve performance.

A peripheral driver will set this flag and network gadget drivers
(e.g. f_ncm.c) will reference the flag via gadget_avoids_skb_reserve().
Signed-off-by: NYoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

It can sometimes be necessary for gadget drivers to process non-standard
control requests, which host devices can send without having sent
USB_REQ_SET_CONFIGURATION.

Therefore, the req_match() usb_function method is enhanced with the new
parameter "config0". When a USB configuration is active, this parameter
is false. When a non-core control request is processed in
composite_setup(), without an active configuration, req_match() of the
USB functions of all available configurations which implement this
function, is called with config0=true. Then the control request gets
processed by the first usb_function instance whose req_match() returns
true.
Signed-off-by: NFelix Hädicke <felixhaedicke@web.de>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

USB spec specifies wMaxPacketSize to be little endian (as other properties),
so when using this variable in the driver we should convert to the current
CPU endianness if necessary.

This patch also introduces usb_ep_align() which does always returns the
aligned buffer size for an endpoint. This is useful to be used by USB requests
allocator functions.
Signed-off-by: NFelipe F. Tonello <eu@felipetonello.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

No more users for it.
Signed-off-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The HOSTPC extension registers found in some EHCI implementations form
a variable-length array, with one element for each port.  Therefore
the hostpc field in struct ehci_regs should be declared as a
zero-length array, not a single-element array.

This fixes a problem reported by UBSAN.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Reported-by: NWilfried Klaebe <linux-kernel@lebenslange-mailadresse.de>
Tested-by: NWilfried Klaebe <linux-kernel@lebenslange-mailadresse.de>
CC: <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As a preparation for another cleanup, this moves the header file
for the phy-msm-usb driver into the driver itself. No other file
includes it any more, and we don't really want it in the global
namespace anyway.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Some SoCs have a single phy-hw-block with multiple phys, this is
modelled by a single phy dts node, so we end up with multiple
controller nodes with a phys property pointing to the phy-node
of the otg-phy.

Only one of these controllers typically is an otg controller, yet we
were checking the first controller who uses a phy from the block and
then end up looking for a dr_mode property in e.g. the ehci controller.

This commit fixes this by adding an arg0 parameter to
of_usb_get_dr_mode_by_phy and make of_usb_get_dr_mode_by_phy
check that this matches the phandle args[0] value when looking for
the otg controller.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

This new set of tracepoints will help all gadget
drivers and UDC drivers when problem appears. Note
that, in order to be able to add tracepoints to
udc-core.c we had to rename that to core.c and
statically link it with trace.c to form
udc-core.o. This is to make sure that module name
stays the same.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

instead of defining all functions as static inlines,
let's move them to udc-core and export them with
EXPORT_SYMBOL_GPL, that way we can make sure that
only GPL drivers will use them.

As a side effect, it'll be nicer to add tracepoints
to the gadget API.

While at that, also fix Kconfig dependencies to
avoid randconfig build failures.
Acked-By: NSebastian Reichel <sre@kernel.org>
Acked-by: NPeter Chen <peter.chen@nxp.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

At least on n900 we have phy-twl4030-usb only generating cable
interrupts, and then have a separate USB PHY.

In order for musb to know the real cable status, we need to
clear any cached state until musb is ready. Otherwise the cable
status interrupts will get just ignored if the status does
not change from the initial state.

To do this, let's add a return value to musb_mailbox(), and
reset cached linkstat to MUSB_UNKNOWN on error. Sorry to cause
a bit of churn here, I should have added that already last time
patching musb_mailbox().
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

By default user could store only valid UDC name in configfs UDC
attr by doing:

echo $UDC_NAME > UDC

Commit (855ed04a "usb: gadget: udc-core: independent registration of
gadgets and gadget drivers") broke this behavior and allowed to store
any arbitrary string in UDC file and udc core was waiting for such
controller to appear.

echo "any arbitrary string here" > UDC

This commit fix this by adding a flag which prevents configfs
gadget from being added to list of pending drivers if UDC with
given name has not been found.
Signed-off-by: NKrzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

The XHCI controller presents two USB buses to the system - one for USB2
and one for USB3. The hub init code (hub_port_init) is reentrant but
only locks one bus per thread, leading to a race condition failure when
two threads attempt to simultaneously initialise a USB2 and USB3 device:

[    8.034843] xhci_hcd 0000:00:14.0: Timeout while waiting for setup device command
[   13.183701] usb 3-3: device descriptor read/all, error -110

On a test system this failure occurred on 6% of all boots.

The call traces at the point of failure are:

Call Trace:
 [<ffffffff81b9bab7>] schedule+0x37/0x90
 [<ffffffff817da7cd>] usb_kill_urb+0x8d/0xd0
 [<ffffffff8111e5e0>] ? wake_up_atomic_t+0x30/0x30
 [<ffffffff817dafbe>] usb_start_wait_urb+0xbe/0x150
 [<ffffffff817db10c>] usb_control_msg+0xbc/0xf0
 [<ffffffff817d07de>] hub_port_init+0x51e/0xb70
 [<ffffffff817d4697>] hub_event+0x817/0x1570
 [<ffffffff810f3e6f>] process_one_work+0x1ff/0x620
 [<ffffffff810f3dcf>] ? process_one_work+0x15f/0x620
 [<ffffffff810f4684>] worker_thread+0x64/0x4b0
 [<ffffffff810f4620>] ? rescuer_thread+0x390/0x390
 [<ffffffff810fa7f5>] kthread+0x105/0x120
 [<ffffffff810fa6f0>] ? kthread_create_on_node+0x200/0x200
 [<ffffffff81ba183f>] ret_from_fork+0x3f/0x70
 [<ffffffff810fa6f0>] ? kthread_create_on_node+0x200/0x200

Call Trace:
 [<ffffffff817fd36d>] xhci_setup_device+0x53d/0xa40
 [<ffffffff817fd87e>] xhci_address_device+0xe/0x10
 [<ffffffff817d047f>] hub_port_init+0x1bf/0xb70
 [<ffffffff811247ed>] ? trace_hardirqs_on+0xd/0x10
 [<ffffffff817d4697>] hub_event+0x817/0x1570
 [<ffffffff810f3e6f>] process_one_work+0x1ff/0x620
 [<ffffffff810f3dcf>] ? process_one_work+0x15f/0x620
 [<ffffffff810f4684>] worker_thread+0x64/0x4b0
 [<ffffffff810f4620>] ? rescuer_thread+0x390/0x390
 [<ffffffff810fa7f5>] kthread+0x105/0x120
 [<ffffffff810fa6f0>] ? kthread_create_on_node+0x200/0x200
 [<ffffffff81ba183f>] ret_from_fork+0x3f/0x70
 [<ffffffff810fa6f0>] ? kthread_create_on_node+0x200/0x200

Which results from the two call chains:

hub_port_init
 usb_get_device_descriptor
  usb_get_descriptor
   usb_control_msg
    usb_internal_control_msg
     usb_start_wait_urb
      usb_submit_urb / wait_for_completion_timeout / usb_kill_urb

hub_port_init
 hub_set_address
  xhci_address_device
   xhci_setup_device

Mathias Nyman explains the current behaviour violates the XHCI spec:

 hub_port_reset() will end up moving the corresponding xhci device slot
 to default state.

 As hub_port_reset() is called several times in hub_port_init() it
 sounds reasonable that we could end up with two threads having their
 xhci device slots in default state at the same time, which according to
 xhci 4.5.3 specs still is a big no no:

 "Note: Software shall not transition more than one Device Slot to the
  Default State at a time"

 So both threads fail at their next task after this.
 One fails to read the descriptor, and the other fails addressing the
 device.

Fix this in hub_port_init by locking the USB controller (instead of an
individual bus) to prevent simultaneous initialisation of both buses.

Fixes: 638139eb ("usb: hub: allow to process more usb hub events in parallel")
Link: https://lkml.org/lkml/2016/2/8/312
Link: https://lkml.org/lkml/2016/2/4/748Signed-off-by: NChris Bainbridge <chris.bainbridge@gmail.com>
Cc: stable <stable@vger.kernel.org>
Acked-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>