This patch adds a new function 'f_uac1'
(f_uac1 with virtual "ALSA card") that
uses recently created u_audio API. Comparing
to legacy f_uac1 function implementation it
doesn't require any real Audio codec to be
present on the device. In f_uac1 audio
streams are simply sinked to and sourced
from a virtual ALSA sound card created
using u_audio API.

Legacy f_uac1 approach is to write audio
samples directly to existing ALSA sound
card

f_uac1 approach is more generic/flexible
one - create an ALSA sound card that
represents USB Audio function and allows to
be used by userspace application that
may choose to do whatever it wants with the
data received from the USB Host and choose
to provide whatever it wants as audio data
to the USB Host.

f_uac1 also has capture support (gadget->host)
thanks to easy implementation via u_audio.
By default, capture interface has 48000kHz/2ch
configuration, same as playback channel has.

f_uac1 descriptors naming convention
uses f_uac2 driver naming convention that
makes it more common and meaningful.

Comparing to f_uac1_legacy, the f_uac1 doesn't
have volume/mute functionality. This is because
the f_uac1 volume/mute feature unit was dummy
implementation since that driver creation (2009)
and never had any real volume control or mute
functionality, so there is no any difference
here.

Since f_uac1 functionality, exposed
interface to userspace (virtual ALSA card),
input parameters are so different comparing
to f_uac1_legacy, that there is no any
reason to keep them in the same file/module,
and separate function was created.

g_audio can be built using one of existing
UAC functions (f_uac1, f_uac1_legacy or f_uac2)
Signed-off-by: NRuslan Bilovol <ruslan.bilovol@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Before introducing new f_uac1 function (with virtual
ALSA card) make current implementation legacy.

This includes renaming of existing files, some
variables, config options and documentation
Signed-off-by: NRuslan Bilovol <ruslan.bilovol@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Abstract the peripheral side ALSA sound card code from
the f_uac2 function into a component that can be called
by various functions, so the various flavors can be split
apart and selectively reused.

Visible changes:
 - add uac_params structure to pass audio paramteres for
   g_audio_setup
 - make ALSA sound card's name configurable
 - add [in/out]_ep_maxpsize
 - allocate snd_uac_chip structure during g_audio_setup
 - add u_audio_[start/stop]_[capture/playback] functions
Signed-off-by: NRuslan Bilovol <ruslan.bilovol@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Simplify f_uac2 by removing platform driver/device
creation; use composite's usb_gadget device as
parent for sound card and for debug prints.
This removes extra layer of code without any functional
change.
Signed-off-by: NRuslan Bilovol <ruslan.bilovol@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

After commit 7e4da3fc ("usb: gadget: composite:
Test get_alt() presence instead of set_alt()") f_uac1
function became broken because it doesn't have
get_alt() callback implementation and composite
framework never set altsetting 1 for audiostreaming
interface. On host site it looks like:

 [424339.017711] 21:1:1: usb_set_interface failed (-32)

Since host can't set altsetting 1, it can't start
playing audio.

In order to fix it implemented get_alt along with
minor improvements (error conditions checking)
similar to what existing f_uac2 has.

Cc: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: NRuslan Bilovol <ruslan.bilovol@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

commit 46ddd79e ("usb: gadget: udc: atmel: Remove AVR32 bits from the
driver") left the accessor macros introduced by commit a3dd3bef ("usb:
gadget: atmel_usba: use endian agnostic IO on ARM"). They can now be
removed.
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Corrected the register to check the 64-bit pointer
capability state. 64-bit pointer implementation capability
was checking in wrong register, which causes the BDC
enumeration failure in 64-bit memory address.

Fixes: efed421a ("usb: gadget: Add UDC driver for
Broadcom USB3.0 device controller IP BDC")
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NSrinath Mannam <srinath.mannam@broadcom.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

finish_td() could be called with a skip option to bypass most of the
function and only call xhci_td_cleanup() at the end.

Remove this skip option and call xhci_td_cleanup() directly instead
when needed

No functional changes
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Get rid of stopped_stream member in virtual endpoint structure as
it is only used in one case when cleaning a halted endpoint.

Pass it as function parameter instead.

No functional changes
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Most transfer events have a TRB pointer indicating which TRB caused
the event.
In the case of streams, transfer events such as
USB Transaction error may have its TRB pointer set to zero.

driver won't know which stream or what TRB on that stream caused
the error, but it can issue a soft reset to recover the transfer.
A soft reset will clear the host side halt of the endpoint without
clearing Data toggle or sequence number, and let the transfer
continue from where it halted.

see xhci section 4.12 streams and 4.6.8.2 soft retry.

USB Transaction errors with a zero TRB pointer are seen with
UAS usb devices.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add soft reset support to cleanup_halted_endpoint().
using soft reset will prevent it from setting a new dequeue pointer to
start the transfer from. Let it continue where it halted.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

xhci supports soft retry recovery when the host halted the host side of an
endopint but the connected USB device is not aware of the halt.

In this case xhci needs to issue a reset endopint command  with a TSP
(Transfer State Preserve) flag set which preserves the Data toggle
and Sequence number of the endpoint.

This feature is needed to handle a few special transfer event types
such as USB Transaction error that don't always point to a causing TRB.

see xhci 4.6.8.1 for more details
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Parse the transfer event first, and remove duplicate debugging
code.

Reorder completion codes according to endpoint state.

No functional changes

We are not handling some transfer events correcly and need to
clean up this before fixing it
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Anurag Kumar Vulisha reported several issues with xhci endpoint
ring caching.

31 Rings are cached per device before a ring is freed.
These cached rings are not used as default if a new ring is needed.
They are only used if the driver fails to allocate memory for a ring.

The current ring cache is more a reason to why we run out memory than a
help when we actually do so.

Anurag Kumar Vulisha tried to use cached rings as a first option and
found new issues with cached ring initialization.
Cached rings were first zeroed and then manually reinitialized with link
trbs etc, but forgetting to set some important bits like cycle toggle bit.

Remove the ring cache completely as it's a faulty premature optimization
eating memory
Reported-by: NAnurag Kumar Vulisha <anuragku@xilinx.com>
Tested-by: NAnurag Kumar Vulisha <anuragku@xilinx.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The original motivation for disabling/enabling Link PM at device
suspend/resume was to force link state to go via U0 before suspend sets
the link state to U3. Going directly from U2 to U3 is not allowed.

Disabling LPM will forced the link state to U0, but will send a lot of
Set port feature requests for evert suspend and resume.

This is not needed as Hub hardware will take care of going via U0
when a U2 -> U3 transition is requested [1]

[1] USB 3.1 specification section 10.16.2.10 Set Port Feature:

"If the value is 3, then host software wants to selectively suspend the
device connected to this port. The hub shall transition the link to U3
from any of the other U states using allowed link state transitions.
If the port is not already in the U0 state, then it shall transition the
port to the U0 state and then initiate the transition to U3.
While this state is active, the hub does not propagate downstream-directed
traffic to this port, but the hub will respond to resume signaling from the
port"
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Using the syzkaller kernel fuzzer, Andrey Konovalov generated the
following error in gadgetfs:

> BUG: KASAN: use-after-free in __lock_acquire+0x3069/0x3690
> kernel/locking/lockdep.c:3246
> Read of size 8 at addr ffff88003a2bdaf8 by task kworker/3:1/903
>
> CPU: 3 PID: 903 Comm: kworker/3:1 Not tainted 4.12.0-rc4+ #35
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
> Workqueue: usb_hub_wq hub_event
> Call Trace:
>  __dump_stack lib/dump_stack.c:16 [inline]
>  dump_stack+0x292/0x395 lib/dump_stack.c:52
>  print_address_description+0x78/0x280 mm/kasan/report.c:252
>  kasan_report_error mm/kasan/report.c:351 [inline]
>  kasan_report+0x230/0x340 mm/kasan/report.c:408
>  __asan_report_load8_noabort+0x19/0x20 mm/kasan/report.c:429
>  __lock_acquire+0x3069/0x3690 kernel/locking/lockdep.c:3246
>  lock_acquire+0x22d/0x560 kernel/locking/lockdep.c:3855
>  __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
>  _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151
>  spin_lock include/linux/spinlock.h:299 [inline]
>  gadgetfs_suspend+0x89/0x130 drivers/usb/gadget/legacy/inode.c:1682
>  set_link_state+0x88e/0xae0 drivers/usb/gadget/udc/dummy_hcd.c:455
>  dummy_hub_control+0xd7e/0x1fb0 drivers/usb/gadget/udc/dummy_hcd.c:2074
>  rh_call_control drivers/usb/core/hcd.c:689 [inline]
>  rh_urb_enqueue drivers/usb/core/hcd.c:846 [inline]
>  usb_hcd_submit_urb+0x92f/0x20b0 drivers/usb/core/hcd.c:1650
>  usb_submit_urb+0x8b2/0x12c0 drivers/usb/core/urb.c:542
>  usb_start_wait_urb+0x148/0x5b0 drivers/usb/core/message.c:56
>  usb_internal_control_msg drivers/usb/core/message.c:100 [inline]
>  usb_control_msg+0x341/0x4d0 drivers/usb/core/message.c:151
>  usb_clear_port_feature+0x74/0xa0 drivers/usb/core/hub.c:412
>  hub_port_disable+0x123/0x510 drivers/usb/core/hub.c:4177
>  hub_port_init+0x1ed/0x2940 drivers/usb/core/hub.c:4648
>  hub_port_connect drivers/usb/core/hub.c:4826 [inline]
>  hub_port_connect_change drivers/usb/core/hub.c:4999 [inline]
>  port_event drivers/usb/core/hub.c:5105 [inline]
>  hub_event+0x1ae1/0x3d40 drivers/usb/core/hub.c:5185
>  process_one_work+0xc08/0x1bd0 kernel/workqueue.c:2097
>  process_scheduled_works kernel/workqueue.c:2157 [inline]
>  worker_thread+0xb2b/0x1860 kernel/workqueue.c:2233
>  kthread+0x363/0x440 kernel/kthread.c:231
>  ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:424
>
> Allocated by task 9958:
>  save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59
>  save_stack+0x43/0xd0 mm/kasan/kasan.c:513
>  set_track mm/kasan/kasan.c:525 [inline]
>  kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:617
>  kmem_cache_alloc_trace+0x87/0x280 mm/slub.c:2745
>  kmalloc include/linux/slab.h:492 [inline]
>  kzalloc include/linux/slab.h:665 [inline]
>  dev_new drivers/usb/gadget/legacy/inode.c:170 [inline]
>  gadgetfs_fill_super+0x24f/0x540 drivers/usb/gadget/legacy/inode.c:1993
>  mount_single+0xf6/0x160 fs/super.c:1192
>  gadgetfs_mount+0x31/0x40 drivers/usb/gadget/legacy/inode.c:2019
>  mount_fs+0x9c/0x2d0 fs/super.c:1223
>  vfs_kern_mount.part.25+0xcb/0x490 fs/namespace.c:976
>  vfs_kern_mount fs/namespace.c:2509 [inline]
>  do_new_mount fs/namespace.c:2512 [inline]
>  do_mount+0x41b/0x2d90 fs/namespace.c:2834
>  SYSC_mount fs/namespace.c:3050 [inline]
>  SyS_mount+0xb0/0x120 fs/namespace.c:3027
>  entry_SYSCALL_64_fastpath+0x1f/0xbe
>
> Freed by task 9960:
>  save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59
>  save_stack+0x43/0xd0 mm/kasan/kasan.c:513
>  set_track mm/kasan/kasan.c:525 [inline]
>  kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:590
>  slab_free_hook mm/slub.c:1357 [inline]
>  slab_free_freelist_hook mm/slub.c:1379 [inline]
>  slab_free mm/slub.c:2961 [inline]
>  kfree+0xed/0x2b0 mm/slub.c:3882
>  put_dev+0x124/0x160 drivers/usb/gadget/legacy/inode.c:163
>  gadgetfs_kill_sb+0x33/0x60 drivers/usb/gadget/legacy/inode.c:2027
>  deactivate_locked_super+0x8d/0xd0 fs/super.c:309
>  deactivate_super+0x21e/0x310 fs/super.c:340
>  cleanup_mnt+0xb7/0x150 fs/namespace.c:1112
>  __cleanup_mnt+0x1b/0x20 fs/namespace.c:1119
>  task_work_run+0x1a0/0x280 kernel/task_work.c:116
>  exit_task_work include/linux/task_work.h:21 [inline]
>  do_exit+0x18a8/0x2820 kernel/exit.c:878
>  do_group_exit+0x14e/0x420 kernel/exit.c:982
>  get_signal+0x784/0x1780 kernel/signal.c:2318
>  do_signal+0xd7/0x2130 arch/x86/kernel/signal.c:808
>  exit_to_usermode_loop+0x1ac/0x240 arch/x86/entry/common.c:157
>  prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
>  syscall_return_slowpath+0x3ba/0x410 arch/x86/entry/common.c:263
>  entry_SYSCALL_64_fastpath+0xbc/0xbe
>
> The buggy address belongs to the object at ffff88003a2bdae0
>  which belongs to the cache kmalloc-1024 of size 1024
> The buggy address is located 24 bytes inside of
>  1024-byte region [ffff88003a2bdae0, ffff88003a2bdee0)
> The buggy address belongs to the page:
> page:ffffea0000e8ae00 count:1 mapcount:0 mapping:          (null)
> index:0x0 compound_mapcount: 0
> flags: 0x100000000008100(slab|head)
> raw: 0100000000008100 0000000000000000 0000000000000000 0000000100170017
> raw: ffffea0000ed3020 ffffea0000f5f820 ffff88003e80efc0 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
>  ffff88003a2bd980: fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>  ffff88003a2bda00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> >ffff88003a2bda80: fc fc fc fc fc fc fc fc fc fc fc fc fb fb fb fb
>                                                                 ^
>  ffff88003a2bdb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>  ffff88003a2bdb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================

What this means is that the gadgetfs_suspend() routine was trying to
access dev->lock after it had been deallocated.  The root cause is a
race in the dummy_hcd driver; the dummy_udc_stop() routine can race
with the rest of the driver because it contains no locking.  And even
when proper locking is added, it can still race with the
set_link_state() function because that function incorrectly drops the
private spinlock before invoking any gadget driver callbacks.

The result of this race, as seen above, is that set_link_state() can
invoke a callback in gadgetfs even after gadgetfs has been unbound
from dummy_hcd's UDC and its private data structures have been
deallocated.

include/linux/usb/gadget.h documents that the ->reset, ->disconnect,
->suspend, and ->resume callbacks may be invoked in interrupt context.
In general this is necessary, to prevent races with gadget driver
removal.  This patch fixes dummy_hcd to retain the spinlock across
these calls, and it adds a spinlock acquisition to dummy_udc_stop() to
prevent the race.

The net2280 driver makes the same mistake of dropping the private
spinlock for its ->disconnect and ->reset callback invocations.  The
patch fixes it too.

Lastly, since gadgetfs_suspend() may be invoked in interrupt context,
it cannot assume that interrupts are enabled when it runs.  It must
use spin_lock_irqsave() instead of spin_lock_irq().  The patch fixes
that bug as well.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: NAndrey Konovalov <andreyknvl@google.com>
CC: <stable@vger.kernel.org>
Acked-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

clk_prepare_enable() can fail here and we must check its return value.
Reviewed-by: NKrzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: NArvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

clk_prepare_enable() can fail here and we must check its return value.
Signed-off-by: NArvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

The commit 47d3946e

	usb: dwc3: refactor gadget endpoint count calculation

refactored dwc3_gadget_init_endpoints() and in particular changed in or
out endpoint numbering to be through. It's not always convenient and
makes code a slightly harder to read.

Introduce a new temporary variable to make it easier to understand what
is going on inside the function.

While doing that, rename local variables as follows:
	u8 num	-> u8 total
	int num -> int kbytes

Replace implicit direction check via epnum with explicit use of
direction variable.

While here, replace %d to %u when compounding endpoint name since we are
using unsigned type.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

If there is no UDC available, the msg register will fail and this
flag will not be set, but the driver is already added into pending
driver list, then the module removal modprobe -r can not remove
the driver from the pending list.
Signed-off-by: NLi Jun <jun.li@nxp.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

The USB3.0 peripheral controller on R-Car SoCs has a dedicated DMAC.
The DMAC needs a "PRD table" in system memory and the DMAC can have
four PRD tables. This patch adds support for the DMAC.
Signed-off-by: NYoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

AVR32 is gone. Now it's time to clean up the driver by removing
leftovers that was used by AVR32 related code.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

clk_prepare_enable() can fail here and we must check its return value.
Signed-off-by: NArvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

If PHY is entering Host mode, we need to enable VBUS.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

If don't reorder initialization like this, we will never be able to
get a reference to ULPI PHYs.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

If PHY is suspended by the time we want to issue ULPI transfers, we
will observe timeouts on the ULPI interface. In order to avoid such
issue, let's make sure PHY is resumed before issuing a ULPI transfer.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

We don't (yet) support PTM_STATUS messages so let's not reply to them
erroneously.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

This file will print out the name of the currently running USB Gadget
Driver. It can be read even when there are no functions loaded.
Suggested-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Move the code which was part of pullup() to the newly introduced
method.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Use this method to make sure we don't try to connect on speeds not
supported by the gadget driver.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

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 patch adds platform driver support for Synopsys UDC.

A new driver file (snps_udc_plat.c) is created for this purpose
where the platform driver registration is done based on OF
node.

Currently, UDC integrated into Broadcom's iProc SoCs (Northstar2
and Cygnus) work with this driver.

New members are added to the UDC data structure for having platform
device support along with extcon and phy support.

Kconfig and Makefiles are modified to select platform driver for
compilation.
Signed-off-by: NRaviteja Garimella <raviteja.garimella@broadcom.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Change the argument from NULL to a struct device for the
dma_pool_create call during dma init.
Signed-off-by: NRaviteja Garimella <raviteja.garimella@broadcom.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

This patch adds a struct device member to UDC data structure and
makes changes to the arguments of dev_err and dev_dbg calls so that
the debug prints work for both pci and platform devices.
Signed-off-by: NRaviteja Garimella <raviteja.garimella@broadcom.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

This patch renames the amd5536udc.c that has the core driver
functionality of Synopsys UDC to snps_udc_core.c

The symbols exported here can be used by any UDC driver that uses
the same Synopsys IP.
Signed-off-by: NRaviteja Garimella <raviteja.garimella@broadcom.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Other unsigned properties return hexadecimal values, follow this
convention when printing b_vendor_code too. Also add newlines to
the OS Descriptor support related properties, like other sysfs
files use.
Reviewed-by: NKrzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: NStefan Agner <stefan@agner.ch>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Currently qw_sign requires UTF-8 character to set, but returns UTF-16
when read. This isn't obvious when simply using cat since the null
characters are not visible, but hexdump unveils the true string:

  # echo MSFT100 > os_desc/qw_sign
  # hexdump -C os_desc/qw_sign
  00000000  4d 00 53 00 46 00 54 00  31 00 30 00 30 00        |M.S.F.T.1.0.0.|

Make qw_sign symmetric by returning an UTF-8 string too. Also follow
common convention and add a new line at the end.
Reviewed-by: NKrzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: NStefan Agner <stefan@agner.ch>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

In an attempt to work around a pinmux over-allocation issue in driver
core, commit dc5878ab ("usb: core: move root hub's device node
assignment after it is added to bus") moved the device-tree node
assignment until after the root hub had been registered.

This not only makes the device-tree node unavailable to the usb driver
during probe, but also prevents the of_node from being linked to in
sysfs and causes a race with user-space for the (recently added) devspec
attribute.

Use the new device_set_of_node_from_dev() helper to reuse the node of
the sysdev device, something which now prevents driver core from trying
to reclaim any pinctrl pins during probe.

Fixes: dc5878ab ("usb: core: move root hub's device node assignment after it is added to bus")
Fixes: 51fa9147 ("usb/core: Added devspec sysfs entry for devices behind the usb hub")
Signed-off-by: NJohan Hovold <johan@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Document that the child-node lookup helper takes a reference to the
device-tree node which needs to be dropped after use.
Signed-off-by: NJohan Hovold <johan@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Make sure to release any OF device-node reference taken when creating
the USB device.

Note that we currently do not hold a reference to the root hub
device-tree node (i.e. the parent controller node).

Fixes: 69bec725 ("USB: core: let USB device know device node")
Cc: stable <stable@vger.kernel.org>	# v4.6
Acked-by: NPeter Chen <peter.chen@nxp.com>
Signed-off-by: NJohan Hovold <johan@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>