This commit checks for the URB_ZERO_PACKET flag and creates an extra
zero-length td if the urb transfer length is a multiple of the endpoint's
max packet length.
Signed-off-by: NReyad Attiyat <reyad.attiyat@gmail.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Right now xhci-plat-hcd can be built when using one of platform specific
drivers only (mvebu/rcar). There shouldn't be such limitation as some
platforms may not require any quirks and may want to just use a generic
driver ("generic-xhci" / "xhci-hcd").
Signed-off-by: NRafał Miłecki <zajec5@gmail.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Replace redundant variable use in return statement.
Signed-off-by: NSaurabh Karajgaonkar <skarajga@visteon.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Replace redundant variable use in return statement.
Signed-off-by: NSaurabh Karajgaonkar <skarajga@visteon.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Replace redundant variable use in return statement.
Signed-off-by: NSaurabh Karajgaonkar <skarajga@visteon.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Replace redundant variable use in return statement.
Signed-off-by: NSaurabh Karajgaonkar <skarajga@visteon.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When using OF defined controllers the platform data struct is shared
between all devices, so it can't be used for device specific settings.
However it is currently used for the OF properties
needs-reset-on-resume and has-transaction-translator.

To fix this issue move setting hcd->has_tt to the probe and
move pdata->reset_on_resume to the private data.
Signed-off-by: NAlban Bedel <albeu@free.fr>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Define and use CONTROL_REGISTER_W1C_MASK to make sure that
w1c bits of usb control register do not get reset while
writing any other bit
Signed-off-by: NNikhil Badola <nikhil.badola@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Phy_clk_valid bit is checked only when the boolean
property phy-clk-valid in present in usb node device tree.
This property is added to the usb node via device tree fixup.
Signed-off-by: NNikhil Badola <nikhil.badola@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Introduce FSL_USB2_PHY_UTMI_DUAL macro for setting phy mode
in SOCs such has T4240, T1040, T2080 which have utmi dual-phy
Signed-off-by: NRamneek Mehresh <ramneek.mehresh@freescale.com>
Signed-off-by: NNikhil Badola <nikhil.badola@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

USB controller version-2.5 requires to enable internal UTMI
phy and program PTS field in PORTSC register before asserting
controller reset. This is must for successful resetting of the
controller and subsequent enumeration of usb devices
Signed-off-by: NNikhil Badola <nikhil.badola@freescale.com>
Signed-off-by: NSuresh Gupta <suresh.gupta@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Replace macros with enumerated type to represent usb ip
controller version
Signed-off-by: NNikhil Badola <nikhil.badola@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

On some boards a GPIO is needed to activate USB controller. Make it
possible to specify such a GPIO in device tree.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The Broadcom ARM SoCs with this usb core need a different
initialization and they have a different core id. This patch adds
support for these USB 2.0 core.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch makes bcma_hcd_create_pdev() not return NULL, but a prober
error code in case of an error.
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Instead of manually handling the frees use devm. There was also a free
missing in the unregister call which is not needed with devm.
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The constants for these numbers were added long time ago, use them.
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

I have never seen any bcma device with an USB host core which was not a
SoC, the bcma devices have an USB device core with a different core id.
Some SoC have IDs with 47XX and 53XX in decimal form which would be
rejected by this check. Instead of fixing this check just remove it.
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix "though" to "through" in documentation of xhci_alloc_streams().
Signed-off-by: NLuis de Bethencourt <luis@debethencourt.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

An incorrect definition of CCR_PM_USBPW3 in ohci-tmio.c is a perennial
source of invalid diagnoses from static scanners, such as in
<http://marc.info/?l=linux-usb&m=143634574527641&w=2>.  This patch
fixes the definition.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Reported-by: NDavid Binderman <dcb314@hotmail.com>
CC: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch fixes a bug introduced by commit 977dcfdc ("USB: OHCI:
don't lose track of EDs when a controller dies").  The commit changed
ed_state from ED_UNLINK to ED_IDLE too early, before finish_urb() had
been called.  The user-visible consequence is that the driver
occasionally crashes or locks up when an URB is submitted while
another URB for the same endpoint is being unlinked.

This patch moves the ED state change later, to the right place.  The
drawback is that now we may unnecessarily execute some instructions
multiple times when a controller dies.  Since controllers dying is an
exceptional occurrence, a little wasted time won't matter.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Reported-by: NHeiko Przybyl <lil_tux@web.de>
Tested-by: NHeiko Przybyl <lil_tux@web.de>
Fixes: 977dcfdc
CC: <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Port link change with port in resume state should not be
reported to usbcore, as this is an internal state to be
handled by xhci driver. Reporting PLC to usbcore may
cause usbcore clearing PLC first and port change event irq
won't be generated.

Cc: <stable@vger.kernel.org>
Signed-off-by: NZhuang Jin Can <jin.can.zhuang@intel.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When the link is just waken, it's in Resume state, and driver sets PLS to
U0. This refers to Phase 1. Phase 2 refers to when the link has completed
the transition from Resume state to U0.

With the fix of xhci: report U3 when link is in resume state, it also
exposes an issue that usb3 roothub and controller can suspend right
after phase 1, and this causes a hard hang in controller.

To fix the issue, we need to prevent usb3 bus suspend if any port is
resuming in phase 1.

[merge separate USB2 and USB3 port resume checking to one -Mathias]
Cc: <stable@vger.kernel.org>
Signed-off-by: NZhuang Jin Can <jin.can.zhuang@intel.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

xhci_hub_report_usb3_link_state() returns pls as U0 when the link
is in resume state, and this causes usb core to think the link is in
U0 while actually it's in resume state. When usb core transfers
control request on the link, it fails with TRB error as the link
is not ready for transfer.

To fix the issue, report U3 when the link is in resume state, thus
usb core knows the link it's not ready for transfer.

Cc: <stable@vger.kernel.org>
Signed-off-by: NZhuang Jin Can <jin.can.zhuang@intel.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When resetting a device the number of active TTs may need to be
corrected by xhci_update_tt_active_eps, but the number of old active
endpoints supplied to it was always zero, so the number of TTs and the
bandwidth reserved for them was not updated, and could rise
unnecessarily.

This affected systems using Intel's Patherpoint chipset, which rely on
software bandwidth checking.  For example, a Lenovo X230 would lose the
ability to use ports on the docking station after enough suspend/resume
cycles because the bandwidth calculated would rise with every cycle when
a suitable device is attached.

The correct number of active endpoints is calculated in the same way as
in xhci_reserve_bandwidth.

Cc: <stable@vger.kernel.org>
Signed-off-by: NBrian Campbell <bacam@z273.org.uk>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

virt_dev->num_cached_rings counts on freed ring and is not updated
correctly. In xhci_free_or_cache_endpoint_ring() function, the free ring
is added into cache and then num_rings_cache is incremented as below:
		virt_dev->ring_cache[rings_cached] =
			virt_dev->eps[ep_index].ring;
		virt_dev->num_rings_cached++;
here, free ring pointer is added to a current index and then
index is incremented.
So current index always points to empty location in the ring cache.
For getting available free ring, current index should be decremented
first and then corresponding ring buffer value should be taken from ring
cache.

But In function xhci_endpoint_init(), the num_rings_cached index is
accessed before decrement.
		virt_dev->eps[ep_index].new_ring =
			virt_dev->ring_cache[virt_dev->num_rings_cached];
		virt_dev->ring_cache[virt_dev->num_rings_cached] = NULL;
		virt_dev->num_rings_cached--;
This is bug in manipulating the index of ring cache.
And it should be as below:
		virt_dev->num_rings_cached--;
		virt_dev->eps[ep_index].new_ring =
			virt_dev->ring_cache[virt_dev->num_rings_cached];
		virt_dev->ring_cache[virt_dev->num_rings_cached] = NULL;

Cc: <stable@vger.kernel.org>
Signed-off-by: NAman Deep <aman.deep@samsung.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The xHCI in Intel CherryView / Braswell Platform requires
a driver workaround to get xHCI D3 working. Without this
workaround, xHCI might not enter D3.

Workaround is to configure SSIC PORT as "unused" before D3
entry and "used" after D3 exit. This is done through a
vendor specific register (PORT2_SSIC_CONFIG_REG2 at offset
0x883c), in xhci suspend / resume callbacks.

Verified xHCI D3 works fine in CherryView / Braswell platform.
Signed-off-by: NRajmohan Mani <rajmohan.mani@intel.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Intel xhci hw that require XHCI_PME_STUCK quirk have as default disabled
xhci from going to D3 state in runtime suspend. Driver needs to verify
it can deal with the hw by calling an ACPI _DSM method to get D3 enabled.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The Octeon OHCI is now supported by the ohci-platform driver, and
USB_OCTEON_OHCI is marked as deprecated.  However, it is currently
still necessary to enable it in order to select
USB_OHCI_BIG_ENDIAN_MMIO.  Make CPU_CAVIUM_OCTEON select that as well,
so that USB_OCTEON_OHCI is really obsolete.

The old ohci-octeon and ehci-octeon drivers also only enabled big-endian
MMIO in case the CPU was big-endian.  Make the selections of
USB_EHCI_BIG_ENDIAN_MMIO and USB_OHCI_BIG_ENDIAN_MMIO conditional, to
match this.

Fixes: 2193dda5 ("USB: host: Remove ehci-octeon and ohci-octeon drivers")
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: linux-mips@linux-mips.org
Cc: David Daney <david.daney@cavium.com>
Cc: Chandrakala Chavva <cchavva@caviumnetworks.com>
Cc: Paul Martin <paul.martin@codethink.co.uk>
Patchwork: https://patchwork.linux-mips.org/patch/10178/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Instead of manually handling the frees use devm. There was also a free
missing in the unregister call which is not needed with devm.
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch makes bcma_hcd_create_pdev() not return NULL, but a prober
error code in case of an error.
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix compilation error in fsl ehci drv because ehci_reset()
and ehci_adjust_port_wakeup_flags() were not exported, and
are used when PM is enabled
Signed-off-by: NRamneek Mehresh <ramneek.mehresh@freescale.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add support for USB controller version-2.5 used in
T4240 rev2.0, T1024, T1040, T2080, LS1021A
Signed-off-by: NNikhil Badola <nikhil.badola@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Check IP version 2.4 for multi port host USB controller and
return FSL_USB_VER_2_4 macro
Signed-off-by: NNikhil Badola <nikhil.badola@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The comment stating that xhci_setup_device() is protected by the address
mutex is not true since
commit 6fecd4f2 ("USB: separate usb_address0 mutexes for each bus")
as xhci handles two buses.
Signed-off-by: NChris Bainbridge <chris.bainbridge@gmail.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix the xhci driver from bluntly setting the transferred length to 0 if
we get a STALL on anything else than the data stage of a control transfer.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We used to write the root port state changes in turn for every port,
sleeping 20ms after every port state change. Suspended usb2 ports need
two state changes, taking minimun 40ms per port.

Now instead poll the Port Link State Change (PLC) bit as
the state change to U0 will set this bit.
Suspended usb2 ports still need the extra 20ms delay, but we now change
all the port states at once so we only need to sleep 20ms once all together
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In the OTG case, the controller might not yet have been
added or is removed before the system suspends.

Assign xhci->main_hcd during probe to prevent NULL
pointer de-reference in xhci_suspend/resume().

Use the hcd->state flag to check if HCD is halted
and if that is so do nothing for xhci_suspend/resume().

[Only for xhci-plat devices, pci devices need it in gen_setup -Mathias]
Signed-off-by: NRoger Quadros <rogerq@ti.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The problem seems to be that if a new device is detected
while we have already removed the shared HCD, then many of the
xhci operations (e.g.  xhci_alloc_dev(), xhci_setup_device())
hang as command never completes.

I don't think XHCI can operate without the shared HCD as we've
already called xhci_halt() in xhci_only_stop_hcd() when shared HCD
goes away. We need to prevent new commands from being queued
not only when HCD is dying but also when HCD is halted.

The following lockup was detected while testing the otg state
machine.

[  178.199951] xhci-hcd xhci-hcd.0.auto: xHCI Host Controller
[  178.205799] xhci-hcd xhci-hcd.0.auto: new USB bus registered, assigned bus number 1
[  178.214458] xhci-hcd xhci-hcd.0.auto: hcc params 0x0220f04c hci version 0x100 quirks 0x00010010
[  178.223619] xhci-hcd xhci-hcd.0.auto: irq 400, io mem 0x48890000
[  178.230677] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002
[  178.237796] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[  178.245358] usb usb1: Product: xHCI Host Controller
[  178.250483] usb usb1: Manufacturer: Linux 4.0.0-rc1-00024-g6111320 xhci-hcd
[  178.257783] usb usb1: SerialNumber: xhci-hcd.0.auto
[  178.267014] hub 1-0:1.0: USB hub found
[  178.272108] hub 1-0:1.0: 1 port detected
[  178.278371] xhci-hcd xhci-hcd.0.auto: xHCI Host Controller
[  178.284171] xhci-hcd xhci-hcd.0.auto: new USB bus registered, assigned bus number 2
[  178.294038] usb usb2: New USB device found, idVendor=1d6b, idProduct=0003
[  178.301183] usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[  178.308776] usb usb2: Product: xHCI Host Controller
[  178.313902] usb usb2: Manufacturer: Linux 4.0.0-rc1-00024-g6111320 xhci-hcd
[  178.321222] usb usb2: SerialNumber: xhci-hcd.0.auto
[  178.329061] hub 2-0:1.0: USB hub found
[  178.333126] hub 2-0:1.0: 1 port detected
[  178.567585] dwc3 48890000.usb: usb_otg_start_host 0
[  178.572707] xhci-hcd xhci-hcd.0.auto: remove, state 4
[  178.578064] usb usb2: USB disconnect, device number 1
[  178.586565] xhci-hcd xhci-hcd.0.auto: USB bus 2 deregistered
[  178.592585] xhci-hcd xhci-hcd.0.auto: remove, state 1
[  178.597924] usb usb1: USB disconnect, device number 1
[  178.603248] usb 1-1: new high-speed USB device number 2 using xhci-hcd
[  190.597337] INFO: task kworker/u4:0:6 blocked for more than 10 seconds.
[  190.604273]       Not tainted 4.0.0-rc1-00024-g6111320 #1058
[  190.610228] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  190.618443] kworker/u4:0    D c05c0ac0     0     6      2 0x00000000
[  190.625120] Workqueue: usb_otg usb_otg_work
[  190.629533] [<c05c0ac0>] (__schedule) from [<c05c10ac>] (schedule+0x34/0x98)
[  190.636915] [<c05c10ac>] (schedule) from [<c05c1318>] (schedule_preempt_disabled+0xc/0x10)
[  190.645591] [<c05c1318>] (schedule_preempt_disabled) from [<c05c23d0>] (mutex_lock_nested+0x1ac/0x3fc)
[  190.655353] [<c05c23d0>] (mutex_lock_nested) from [<c046cf8c>] (usb_disconnect+0x3c/0x208)
[  190.664043] [<c046cf8c>] (usb_disconnect) from [<c0470cf0>] (_usb_remove_hcd+0x98/0x1d8)
[  190.672535] [<c0470cf0>] (_usb_remove_hcd) from [<c0485da8>] (usb_otg_start_host+0x50/0xf4)
[  190.681299] [<c0485da8>] (usb_otg_start_host) from [<c04849a4>] (otg_set_protocol+0x5c/0xd0)
[  190.690153] [<c04849a4>] (otg_set_protocol) from [<c0484b88>] (otg_set_state+0x170/0xbfc)
[  190.698735] [<c0484b88>] (otg_set_state) from [<c0485740>] (otg_statemachine+0x12c/0x470)
[  190.707326] [<c0485740>] (otg_statemachine) from [<c0053c84>] (process_one_work+0x1b4/0x4a0)
[  190.716162] [<c0053c84>] (process_one_work) from [<c00540f8>] (worker_thread+0x154/0x44c)
[  190.724742] [<c00540f8>] (worker_thread) from [<c0058f88>] (kthread+0xd4/0xf0)
[  190.732328] [<c0058f88>] (kthread) from [<c000e810>] (ret_from_fork+0x14/0x24)
[  190.739898] 5 locks held by kworker/u4:0/6:
[  190.744274]  #0:  ("%s""usb_otg"){.+.+.+}, at: [<c0053bf4>] process_one_work+0x124/0x4a0
[  190.752799]  #1:  ((&otgd->work)){+.+.+.}, at: [<c0053bf4>] process_one_work+0x124/0x4a0
[  190.761326]  #2:  (&otgd->fsm.lock){+.+.+.}, at: [<c048562c>] otg_statemachine+0x18/0x470
[  190.769934]  #3:  (usb_bus_list_lock){+.+.+.}, at: [<c0470ce8>] _usb_remove_hcd+0x90/0x1d8
[  190.778635]  #4:  (&dev->mutex){......}, at: [<c046cf8c>] usb_disconnect+0x3c/0x208
[  190.786700] INFO: task kworker/1:0:14 blocked for more than 10 seconds.
[  190.793633]       Not tainted 4.0.0-rc1-00024-g6111320 #1058
[  190.799567] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  190.807783] kworker/1:0     D c05c0ac0     0    14      2 0x00000000
[  190.814457] Workqueue: usb_hub_wq hub_event
[  190.818866] [<c05c0ac0>] (__schedule) from [<c05c10ac>] (schedule+0x34/0x98)
[  190.826252] [<c05c10ac>] (schedule) from [<c05c4e40>] (schedule_timeout+0x13c/0x1ec)
[  190.834377] [<c05c4e40>] (schedule_timeout) from [<c05c19f0>] (wait_for_common+0xbc/0x150)
[  190.843062] [<c05c19f0>] (wait_for_common) from [<bf068a3c>] (xhci_setup_device+0x164/0x5cc [xhci_hcd])
[  190.852986] [<bf068a3c>] (xhci_setup_device [xhci_hcd]) from [<c046b7f4>] (hub_port_init+0x3f4/0xb10)
[  190.862667] [<c046b7f4>] (hub_port_init) from [<c046eb64>] (hub_event+0x704/0x1018)
[  190.870704] [<c046eb64>] (hub_event) from [<c0053c84>] (process_one_work+0x1b4/0x4a0)
[  190.878919] [<c0053c84>] (process_one_work) from [<c00540f8>] (worker_thread+0x154/0x44c)
[  190.887503] [<c00540f8>] (worker_thread) from [<c0058f88>] (kthread+0xd4/0xf0)
[  190.895076] [<c0058f88>] (kthread) from [<c000e810>] (ret_from_fork+0x14/0x24)
[  190.902650] 5 locks held by kworker/1:0/14:
[  190.907023]  #0:  ("usb_hub_wq"){.+.+.+}, at: [<c0053bf4>] process_one_work+0x124/0x4a0
[  190.915454]  #1:  ((&hub->events)){+.+.+.}, at: [<c0053bf4>] process_one_work+0x124/0x4a0
[  190.924070]  #2:  (&dev->mutex){......}, at: [<c046e490>] hub_event+0x30/0x1018
[  190.931768]  #3:  (&port_dev->status_lock){+.+.+.}, at: [<c046eb50>] hub_event+0x6f0/0x1018
[  190.940558]  #4:  (&bus->usb_address0_mutex){+.+.+.}, at: [<c046b458>] hub_port_init+0x58/0xb10
Signed-off-by: NRoger Quadros <rogerq@ti.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Don't set xhci->shared_hcd to NULL in xhci_stop() as we have
still not de-allocated it. It was resulting in a NULL pointer
de-reference if usb_add/remove_hcd() is called repeatedly.

We want repeated add/remove to work for the OTG use case.
Signed-off-by: NRoger Quadros <rogerq@ti.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>