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: Chris Bainbridge <chris.bainbridge@gmail.com>
Cc: stable <stable@vger.kernel.org>
Acked-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Init data marked const should be annotated with __initconst for
correctness and not __initdata.  This also fixes LTO builds that
otherwise fail with section mismatch errors.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usbdev_vm_ops is used in devio.c only, so declare it as static
Signed-off-by: Michele Curti <michele.curti@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

urb allocation will fail when usbtest_alloc_urb() tries to
allocate zero length buffer, but it doesn't need it in fact,
so just skips buffer allocation in the case.
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

NULL pointer dereferrence will happen when class driver
wants to allocate zero length buffer and pool_max[0]
can't be used, so simply returns NULL in the case.
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

With the addition of VUDC, the USBIP stack can now be used on
configurations without USB host support, but trying to build
it with USB gadget support disabled fails with

drivers/usb/built-in.o: In function `vep_dequeue':
vudc_main.c:(.text+0xa6ddc): undefined reference to `usb_gadget_giveback_request'
drivers/usb/built-in.o: In function `nuke':
vudc_main.c:(.text+0xa6ea8): undefined reference to `usb_gadget_giveback_request'
drivers/usb/built-in.o: In function `vudc_device_reset':
vudc_main.c:(.text+0xa720c): undefined reference to `usb_gadget_udc_reset'
drivers/usb/built-in.o: In function `vudc_probe':

This addresses both issues, by changing the dependency for USBIP_CORE
to USB_COMMON, and adding additional dependencies on USB or USB_GADGET
for the individual portions as needed.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 9360575c ("usbip: vudc: Add vudc to Kconfig")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds a code fragment to ignore completing URBs in closing
connection.

Regarding this patch, 2 execution contexts are related.

1) stub_tx.c: stub_complete() which is called from USB core
1-1) add to unlink list and free URB or
1-2) move to tx list

2) stub_dev.c: stub_shutdown_connection() which is invoked by unbind
operation through sysfs.
2-1) stop TX/RX threads
2-2) close TCP connection and set ud.tcp_socket to NULL
2-3) cleanup pending URBs by stub_device_cleanup_urbs(sdev)
2-4) free unlink list (no lock)

In the race condition, URBs which will be cleared in 2-3) may be
handled in 1).
In case 1-1), it will not be transferred bcause tx threads are stooped
in 2-1).
In case 1-2), may be freed in 2-4).

With this patch, after 2-2), completing URBs in 1) will not be handled
and cleared in 2-3).

The kernel log with this patch is as below.

kernel: usbip_core: usbip_kernel_unlink:792: shutting down tcp_socket
ef61d980
kernel: usbip-host 1-3: free sdev f5df6180
kernel: usbip-host 1-3: free urb f5df6700
kernel: usbip-host 1-3: Enter
kernel: usbip_core: usbip_stop_eh:132: usbip_eh waiting completion 5
kernel: usbip_host: stub_complete:71: complete! status 0
kernel: usbip_host: stub_complete:102: ignore urb for closed connection
e725fc00 (*)
kernel: usbip_host: stub_complete:71: complete! status -2
kernel: usbip-host 1-3: stopped by a call to usb_kill_urb() because of
cleaning up a virtual connection
kernel: usbip-host 1-3: free urb e725fc00 (**)
kernel: usbip-host 1-3: free urb e725e000
kernel: usbip_host: stub_complete:71: complete! status -2
kernel: usbip-host 1-3: stopped by a call to usb_kill_urb() because of
cleaning up a virtual connection
kernel: usbip-host 1-3: free urb e725f800
kernel: usbip_host: stub_complete:71: complete! status -2
kernel: usbip-host 1-3: stopped by a call to usb_kill_urb() because of
cleaning up a virtual connection
kernel: usbip-host 1-3: free urb e725e800
kernel: usbip_host: stub_complete:71: complete! status -2
kernel: usbip-host 1-3: stopped by a call to usb_kill_urb() because of
cleaning up a virtual connection
kernel: usbip-host 1-3: device reset
kernel: usbip-host 1-3: lock for reset
kernel: usbip_host: store_match_busid:178: del busid 1-3
kernel: uvcvideo: Found UVC 1.00 device Venus USB2.0 Camera (056e:700a)
kernel: input: Venus USB2.0 Camera as
/devices/pci0000:00/0000:00:1a.7/usb1/1-3/1-3:1.0/input/input22

(*) skipped with this patch in completion
(**) released in 2-3
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

As find_endpoint() is a global funcion rename it to vudc_find_endpoint()
to clearly mark where does it come from.
Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix NULL pointer dereference and obsolete comments forgotten when
usbip server was converted from an interface driver to a device driver.
Signed-off-by: Alexander Popov <alpopov@ptsecurity.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix WARN_ON() macro usage as suggested by Felipe.
Instead of using:
if (cond) {
   WARN_ON(1);
   do_stuff();
}

Use a better pattern with WARN_ON() placed in if condition:

if (WARN_ON(cond))
   do_stuff();
Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

As vudc provides some new attributes using sysfs infrastructure,
add a suitable documentation file for those attributes.
Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Felipe writes:

usb: changes for v4.7 merge window

Here's the big USB Gadget pull request. This time
not as large as usual with only 57 non-merge
commits.

The most important part here is, again, all the work
on dwc3. This time around we're treating all
endpoints (except for control endpoint) exactly the
same. They all have the same amount of TRBs on the
ring, they all treat the ring as an actual ring with
a link TRB pointing to the head, etc.

We're also helping the host side burst (on
SuperSpeed GEN1 or GEN2 at least) for as long as
possible until the endpoint returns NRDY.

Other than this big TRB ring rework on dwc3, we also
have a dwc3-omap DMA initialization fix, some extra
debugfs files to aid in some odd debug sessions and
a complete removal of our FIFO resizing logic.

We have a new quirk for some dwc3 P3 quirk in some
implementations.

The rest is basically non-critical fixes and the
usual cleanups.

Now that we calculate DCFG.NUMP, we can disable
dwc3's automatic calculation so we maximize our
chances of very high throughtput through the use of
bursts.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

NumP field of DCFG register is used on NumP field of
ACK TP header and it tells the host how many packets
an endpoint can receive before waiting for
synchronization.

Documentation says it should be set to anything
<=bMaxBurst. Interestingly, however, this setting is
not per-endpoint how it should be (different
endpoints could have different burst sizes), but
things seem to work okay right now.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

Cleanup in probe if we fail to get dr_mode.
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

In case of DDMA mode we don't need to get an SOF interrupt so disable
the unmasking of SOF interrupt in DDMA mode.
Signed-off-by: Sevak Arakelyan <sevaka@synopsys.com>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

This is safety change added while doing slub debugging.

Affected functions:
dwc2_hcd_qtd_unlink_and_free()
_dwc2_hcd_urb_enqueue()
Signed-off-by: Vardan Mikayelyan <mvardan@synopsys.com>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

In host slave mode, the core asserts the rxready, txfifoempty interrupts
that get serviced in the gadget irq handler. Prevent servicing of these
when not in the gadget mode of operation.
Signed-off-by: Vardan Mikayelyan <mvardan@synopsys.com>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

Replaced the WARN_ON with a check and return of -EINVAL in the
dwc2_hsotg_ep_enable function if ep0 is passed in.
Signed-off-by: Vahram Aharonyan <vahrama@synopsys.com>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

if Start Transfer command fails, let's try a little
harder to figure out why the command failed and give
slightly better return codes. This will be usefulf
or isochronous endpoints, at least, which could
decide to retry a given request.
Signed-off-by: Konrad Leszczynski <konrad.leszczynski@intel.com>
Signed-off-by: Rafal Redzimski <rafal.f.redzimski@intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

If a gadget driver loaded to a Superspeed-capable
peripheral controller, using a Superspeed cable,
doesn't provide Superspeed descriptors, we will get
a NULL pointer dereference.

In order to avoid that situation, we will try to
find any valid descriptors we can. If no set of
descriptors is passed in, then we'll let that gadget
oops anyhow.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

For convenience, passing the dwc3 platform device as a
parameter to dwc3_pci_quirks() function.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

Setting the ACPI companion before calling dwc3_pci_quirks.
The ACPI companion will be set unconditionally as the
primary fwnode, overriding any previously set primary
fwnode. This will make sure that any build-in properties
added to the platform device will be added as the secondary
fwnode in cases where also ACPI companion exists.
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

In case host sends us an unsupported test mode, we
*must* stall this request. This will tell the host
that the selector is invalid and we won't put the
controller in unsupported test modes which could
have undetermined side-effects.
Signed-off-by: Fei Yang <fei.yang@intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

whc_init already calls whc_clean_up if an error occurs during
the initialization, so calling it again if whc_init fails at
the end of wch_probe will cause double free errors.  Fix this
by bailing out on an whc_init failure to a new label that avoids
doing the duplicated whc_clean_up.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Thanks to switching to devm_gpiod_get:
1) We don't have to pass fwnode pointer
2) We can request initial GPIO value at getting call
This was successfully tested on Netgear R6250 (BCM4708).
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Now that there are no more users for
xhci_plat_type_is(), we can safely remove it.
Acked-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Now that the code has been refactored enough,
switching over to using ->plat_start() and
->init_quirk() becomes a very simple patch.

After this patch, there are no further uses for
xhci_plat_type_is() which will be removed in a
follow-up patch.
Acked-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Just like RCAR's init_quirk() we want mvebu's to use
struct usb_hcd * as argument too. This is another
step towards removing xhci_plat_type_is().
Acked-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

xhci_plat_setup() is the rightful place for
xhci_mvebu_mbus_init_quirk(), so let's move it there
in order to make it simpler to get rid of
xhci_plat_type_is() later on.
Acked-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

these two methods will be used to hide
platform-specific details so we can get rid of
xhci_plat_type_is() in a later patch.
Acked-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

We're preparing to remove xhci_plat_type_is() in
favor of a better approach where we define function
pointers ahead of time. This will let us make
assumptions about which platforms we're running on
and which platform-specific functions we should call.
Acked-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
[delete extra comma in function parameters -Mathias]
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Move duplicate code from xhci_queue_intr_tx()
and xhci_queue_isoc_tx_prepare() to the check_interval() function.
Signed-off-by: Alexandr Ivanov <alexandr.sky@gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove duplicate function xhci_urb_to_transfer_ring from xhci.c.
We have same function in xhci-ring.c.
Signed-off-by: Alexandr Ivanov <alexandr.sky@gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In drivers/usb/host/xhci-ring.c there are two functions
(xhci_queue_bulk_tx and queue_bulk_sg_tx) that are very similar,
so a lot of code duplication.
This patch merges these functions into to one xhci_queue_bulk_tx.
Also counting the needed TRBs is merged and refactored.
Signed-off-by: Alexandr Ivanov <alexandr.sky@gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Restructure usb_sg_cancel() so we don't have to disable interrupts
while cancelling the URBs.
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: David Mosberger <davidm@egauge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb_submit_urb() may take quite long to execute.  For example, a
single sg list may have 30 or more entries, possibly leading to that
many calls to DMA-map pages.  This can cause interrupt latency of
several hundred micro-seconds.

Avoid the problem by releasing the io->lock spinlock and re-enabling
interrupts before calling usb_submit_urb().  This opens races with
usb_sg_cancel() and sg_complete().  Handle those races by using
usb_block_urb() to stop URBs from being submitted after
usb_sg_cancel() or sg_complete() with error.

Note that usb_unlink_urb() is guaranteed to return -ENODEV if
!io->urbs[i]->dev and since the -ENODEV case is already handled,
we don't have to check for !io->urbs[i]->dev explicitly.

Before this change, reading 512MB from an ext3 filesystem on a USB
memory stick showed a throughput of 12 MB/s with about 500 missed
deadlines.

With this change, reading the same file gave the same throughput but
only one or two missed deadlines.
Signed-off-by: David Mosberger <davidm@egauge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Add the driver to Kconfig to make it visible in menuconfig
and allow people to compile it.

This commit is a result of cooperation between Samsung R&D Institute
Poland and Open Operating Systems Student Society at University
of Warsaw (O2S3@UW) consisting of:

    Igor Kotrasinski <ikotrasinsk@gmail.com>
    Karol Kosik <karo9@interia.eu>
    Ewelina Kosmider <3w3lfin@gmail.com>
    Dawid Lazarczyk <lazarczyk.dawid@gmail.com>
    Piotr Szulc <ps347277@students.mimuw.edu.pl>

Tutor and project owner:
    Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Igor Kotrasinski <i.kotrasinsk@samsung.com>
Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Modify userspace tools to allow exporting and connecting to vudc.

This commit is a result of cooperation between Samsung R&D Institute
Poland and Open Operating Systems Student Society at University
of Warsaw (O2S3@UW) consisting of:

   Igor Kotrasinski <ikotrasinsk@gmail.com>
   Karol Kosik <karo9@interia.eu>
   Ewelina Kosmider <3w3lfin@gmail.com>
   Dawid Lazarczyk <lazarczyk.dawid@gmail.com>
   Piotr Szulc <ps347277@students.mimuw.edu.pl>

Tutor and project owner:
   Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Igor Kotrasinski <i.kotrasinsk@samsung.com>
Signed-off-by: Ewelina Kosmider <3w3lfin@gmail.com>
[Various bug fixes and improvements]
Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Adds an equivalent of usbip_host_driver for the vudc. Most
of the code is already shared, but this adds some vudc specific
code for getting information about devices.

Based on code created in cooperation with Open Operating Systems
Student Society at University of Warsaw (O2S3@UW) consisting of:

   Igor Kotrasinski <ikotrasinsk@gmail.com>
   Karol Kosik <karo9@interia.eu>
   Ewelina Kosmider <3w3lfin@gmail.com>
   Dawid Lazarczyk <lazarczyk.dawid@gmail.com>
   Piotr Szulc <ps347277@students.mimuw.edu.pl>

Tutor and project owner:
   Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>