When checking a new device's descriptors, the USB core does not check
for duplicate endpoint addresses.  This can cause a problem when the
sysfs files for those endpoints are created; trying to create multiple
files with the same name will provoke a WARNING:

WARNING: CPU: 2 PID: 865 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x8a/0xa0
sysfs: cannot create duplicate filename
'/devices/platform/dummy_hcd.0/usb2/2-1/2-1:64.0/ep_05'
Kernel panic - not syncing: panic_on_warn set ...

CPU: 2 PID: 865 Comm: kworker/2:1 Not tainted 4.9.0-rc7+ #34
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Workqueue: usb_hub_wq hub_event
 ffff88006bee64c8 ffffffff81f96b8a ffffffff00000001 1ffff1000d7dcc2c
 ffffed000d7dcc24 0000000000000001 0000000041b58ab3 ffffffff8598b510
 ffffffff81f968f8 ffffffff850fee20 ffffffff85cff020 dffffc0000000000
Call Trace:
 [<     inline     >] __dump_stack lib/dump_stack.c:15
 [<ffffffff81f96b8a>] dump_stack+0x292/0x398 lib/dump_stack.c:51
 [<ffffffff8168c88e>] panic+0x1cb/0x3a9 kernel/panic.c:179
 [<ffffffff812b80b4>] __warn+0x1c4/0x1e0 kernel/panic.c:542
 [<ffffffff812b8195>] warn_slowpath_fmt+0xc5/0x110 kernel/panic.c:565
 [<ffffffff819e70ca>] sysfs_warn_dup+0x8a/0xa0 fs/sysfs/dir.c:30
 [<ffffffff819e7308>] sysfs_create_dir_ns+0x178/0x1d0 fs/sysfs/dir.c:59
 [<     inline     >] create_dir lib/kobject.c:71
 [<ffffffff81fa1b07>] kobject_add_internal+0x227/0xa60 lib/kobject.c:229
 [<     inline     >] kobject_add_varg lib/kobject.c:366
 [<ffffffff81fa2479>] kobject_add+0x139/0x220 lib/kobject.c:411
 [<ffffffff82737a63>] device_add+0x353/0x1660 drivers/base/core.c:1088
 [<ffffffff82738d8d>] device_register+0x1d/0x20 drivers/base/core.c:1206
 [<ffffffff82cb77d3>] usb_create_ep_devs+0x163/0x260 drivers/usb/core/endpoint.c:195
 [<ffffffff82c9f27b>] create_intf_ep_devs+0x13b/0x200 drivers/usb/core/message.c:1030
 [<ffffffff82ca39d3>] usb_set_configuration+0x1083/0x18d0 drivers/usb/core/message.c:1937
 [<ffffffff82cc9e2e>] generic_probe+0x6e/0xe0 drivers/usb/core/generic.c:172
 [<ffffffff82caa7fa>] usb_probe_device+0xaa/0xe0 drivers/usb/core/driver.c:263

This patch prevents the problem by checking for duplicate endpoint
addresses during enumeration and skipping any duplicates.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Reported-by: NAndrey Konovalov <andreyknvl@google.com>
Tested-by: NAndrey Konovalov <andreyknvl@google.com>
CC: <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The gpiod_get* function family does not want the -gpio suffix.
Use devm_gpiod_get_index_optional instead of devm_gpiod_get_optional.
The descriptor based APIs handle active high/low automatically.
The vbus-gpios are output, request enable while getting the gpio.
Don't try to get any vbus-gpios for ports outside num-ports.

WTF? Big sigh.

Fixes: 054d4b7b ("usb: ohci-at91: Use descriptor-based gpio APIs")
Signed-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This device gives the following error on detection.
xhci_hcd 0000:00:11.0: ERROR Transfer event for disabled endpoint or
incorrect stream ring

The same error is not seen when it is added to unusual_device
list with US_FL_NO_REPORT_OPCODES passed.
Signed-off-by: NGeorge Cherian <george.cherian@cavium.com>
Signed-off-by: NOliver Neukum <oneukun@suse.com>
CC: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If CONFIG_PM=n:

    drivers/usb/core/hub.c:107: warning: ‘hub_usb3_port_prepare_disable’ declared inline after being called
    drivers/usb/core/hub.c:107: warning: previous declaration of ‘hub_usb3_port_prepare_disable’ was here

To fix this, move hub_port_disable() after
hub_usb3_port_prepare_disable(), and adjust forward declarations.

Fixes: 37be6676 ("usb: hub: Fix auto-remount of safely removed or ejected USB-3 devices")
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The function bfin_fifo_offset is defined but not used:

drivers/usb/musb/blackfin.c:36:12: warning: ‘bfin_fifo_offset’ defined
but not used [-Wunused-function]
 static u32 bfin_fifo_offset(u8 epnum)
             ^~~~~~~~~~~~~~~~

Adding bfin_fifo_offset to bfin_ops fixes this warning and allows musb
core to call this function instead of default_fifo_offset.

Fixes: cc92f681 ("usb: musb: Populate new IO functions for blackfin")
Signed-off-by: NJérémy Lefaure <jeremy.lefaure@lse.epita.fr>
Signed-off-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The function musb_run_resume_work is called only when CONFIG_PM is
enabled. So this function should not be defined when CONFIG_PM is
disabled. Otherwise the compiler issues a warning:

drivers/usb/musb/musb_core.c:2057:12: error: ‘musb_run_resume_work’ defined but
not used [-Werror=unused-function]
 static int musb_run_resume_work(struct musb *musb)
            ^~~~~~~~~~~~~~~~~~~~
Signed-off-by: NJérémy Lefaure <jeremy.lefaure@lse.epita.fr>
Signed-off-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When unloading omap2430, we can get the following splat:

WARNING: CPU: 1 PID: 295 at kernel/irq/manage.c:1478 __free_irq+0xa8/0x2c8
Trying to free already-free IRQ 4
...
[<c01a8b78>] (free_irq) from [<bf0aea84>]
(musbhs_dma_controller_destroy+0x28/0xb0 [musb_hdrc])
[<bf0aea84>] (musbhs_dma_controller_destroy [musb_hdrc]) from
[<bf09f88c>] (musb_remove+0xf0/0x12c [musb_hdrc])
[<bf09f88c>] (musb_remove [musb_hdrc]) from [<c056a384>]
(platform_drv_remove+0x24/0x3c)
...

This is because the irq number in use is 260 nowadays, and the dma
controller is using u8 instead of int.

Fixes: 6995eb68 ("USB: musb: enable low level DMA operation for Blackfin")
Signed-off-by: NTony Lindgren <tony@atomide.com>
[b-liu@ti.com: added Fixes tag]
Signed-off-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

During dma teardown for dequque urb, if musb load is high, musb might
generate bogus rx ep interrupt even when the rx fifo is flushed. In such
case any of the follow log messages could happen.

    musb_host_rx 1853: BOGUS RX2 ready, csr 0000, count 0

    musb_host_rx 1936: RX3 dma busy, csr 2020

As mentioned in the current inline comment, clearing ep interrupt in the
teardown path avoids the bogus interrupt, so implement clear_ep_rxintr()
callback.

This bug seems to be existing since the initial driver for musb support,
but I only validated the fix back to v4.1, so only cc stable for v4.1+.

cc: stable@vger.kernel.org # 4.1+
Signed-off-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

During dma teardown for dequque urb, if musb load is high, musb might
generate bogus rx ep interrupt even when the rx fifo is flushed. In such
case any of the follow log messages could happen.

	musb_host_rx 1853: BOGUS RX2 ready, csr 0000, count 0

	musb_host_rx 1936: RX3 dma busy, csr 2020

As mentioned in the current inline comment, clearing ep interrupt in the
teardown path avoids the bogus interrupt.

Clearing ep interrupt is platform dependent, so this patch adds a
platform callback to allow glue driver to clear the ep interrupt.

This bug seems to be existing since the initial driver for musb support,
but I only validated the fix back to v4.1, so only cc stable for v4.1+.

cc: stable@vger.kernel.org # 4.1+
Signed-off-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Merge tag 'usb-serial-4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial into usb-linus

Johan writes:

USB-serial fixes for v4.10-rc3

These fixes address a number of long-standing issues in various
USB-serial drivers which would lead to crashes should a malicious device
lack the expected endpoints.

Included are also a few related fixes, and a couple of unrelated ones
that were found during my survey (e.g. a memleak and a
sleep-while-atomic).

A compiler warning revealed an error-handling issue in the new f81534
driver which is also fixed.
Signed-off-by: NJohan Hovold <johan@kernel.org>

Fix NULL-pointer dereference in open() should a malicious device lack
the expected endpoints:

Unable to handle kernel NULL pointer dereference at virtual address 00000030
..
[<bf06a6b0>] (ti_open [ti_usb_3410_5052]) from [<bf02e118>] (serial_port_activate+0x68/0x98 [usbserial])

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Fix NULL-pointer dereference in open() should the device lack the
expected endpoints:

Unable to handle kernel NULL pointer dereference at virtual address 00000030
...
PC is at spcp8x5_open+0x30/0xd0 [spcp8x5]

Fixes: 619a6f1d ("USB: add usb-serial spcp8x5 driver")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

The write URB was being killed using the synchronous interface while
holding a spin lock in close().

Simply drop the lock and busy-flag update, something which would have
been taken care of by the completion handler if the URB was in flight.

Fixes: f7a33e60 ("USB: serial: add quatech2 usb to serial driver")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Fix NULL-pointer dereference in open() should a type-0 or type-1 device
lack the expected endpoints:

Unable to handle kernel NULL pointer dereference at virtual address 00000030
...
PC is at pl2303_open+0x38/0xec [pl2303]

Note that a missing interrupt-in endpoint would have caused open() to
fail.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Fix NULL-pointer dereference in open() should the device lack the
expected endpoints:

Unable to handle kernel NULL pointer dereference at virtual address 00000030
...
PC is at oti6858_open+0x30/0x1d0 [oti6858]

Note that a missing interrupt-in endpoint would have caused open() to
fail.

Fixes: 49cdee0e ("USB: oti6858 usb-serial driver (in Nokia CA-42
cable)")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Fix NULL-pointer dereferences at open() and disconnect() should the
device lack the expected bulk-out endpoints:

Unable to handle kernel NULL pointer dereference at virtual address 000000b4
...
[c0170ff0>] (__lock_acquire) from [<c0172f00>] (lock_acquire+0x108/0x264)
[<c0172f00>] (lock_acquire) from [<c06a5090>] (_raw_spin_lock_irqsave+0x58/0x6c)
[<c06a5090>] (_raw_spin_lock_irqsave) from [<c0470684>] (tty_port_tty_set+0x28/0xa4)
[<c0470684>] (tty_port_tty_set) from [<bf08d384>] (omninet_open+0x30/0x40 [omninet])
[<bf08d384>] (omninet_open [omninet]) from [<bf07c118>] (serial_port_activate+0x68/0x98 [usbserial])

Unable to handle kernel NULL pointer dereference at virtual address 00000234
...
[<bf01f418>] (omninet_disconnect [omninet]) from [<bf0016c0>] (usb_serial_disconnect+0xe4/0x100 [usbserial])

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

The interrupt URB is killed at final port close since commit
0de9a702 ("USB: overhaul of mos7840 driver").

Fixes: 0de9a702 ("USB: overhaul of mos7840 driver")
Signed-off-by: NJohan Hovold <johan@kernel.org>

Remove code to manage a write URB that was never allocated.
Signed-off-by: NJohan Hovold <johan@kernel.org>

Fix NULL-pointer dereference in open() should the device lack the
expected endpoints:

Unable to handle kernel NULL pointer dereference at virtual address 00000030
...
PC is at mos7840_open+0x88/0x8dc [mos7840]

Note that we continue to treat the interrupt-in endpoint as optional for
now.

Fixes: 3f542974 ("USB: Moschip 7840 USB-Serial Driver")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Since commit b69578df ("USB: usbserial: mos7720: add support for
parallel port on moschip 7715"), the interrupt urb is no longer
submitted at first port open and the endpoint-address initialisation at
port-probe is no longer used.
Signed-off-by: NJohan Hovold <johan@kernel.org>

A static usb-serial-driver structure that is used to initialise the
interrupt URB was modified during probe depending on the currently
probed device type, something which could break a parallel probe of a
device of a different type.

Fix this up by overriding the default completion callback for MCS7715
devices in attach() instead. We may want to use two usb-serial driver
instances for the two types later.

Fixes: fb088e33 ("USB: serial: add support for serial port on the
moschip 7715")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Do not submit the interrupt URB until after the parport has been
successfully registered to avoid another use-after-free in the
completion handler when accessing the freed parport private data in case
of a racing completion.

Fixes: b69578df ("USB: usbserial: mos7720: add support for parallel
port on moschip 7715")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

The interrupt URB was submitted on probe but never stopped on probe
errors. This can lead to use-after-free issues in the completion
handler when accessing the freed usb-serial struct:

Unable to handle kernel paging request at virtual address 6b6b6be7
...
[<bf052e70>] (mos7715_interrupt_callback [mos7720]) from [<c052a894>] (__usb_hcd_giveback_urb+0x80/0x140)
[<c052a894>] (__usb_hcd_giveback_urb) from [<c052a9a4>] (usb_hcd_giveback_urb+0x50/0x138)
[<c052a9a4>] (usb_hcd_giveback_urb) from [<c0550684>] (musb_giveback+0xc8/0x1cc)

Fixes: b69578df ("USB: usbserial: mos7720: add support for parallel
port on moschip 7715")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Fix NULL-pointer dereference at port open if a device lacks the expected
bulk in and out endpoints.

Unable to handle kernel NULL pointer dereference at virtual address 00000030
...
[<bf071c20>] (mos7720_open [mos7720]) from [<bf0490e0>] (serial_port_activate+0x68/0x98 [usbserial])
[<bf0490e0>] (serial_port_activate [usbserial]) from [<c0470ca4>] (tty_port_open+0x9c/0xe8)
[<c0470ca4>] (tty_port_open) from [<bf049d98>] (serial_open+0x48/0x6c [usbserial])
[<bf049d98>] (serial_open [usbserial]) from [<c0469178>] (tty_open+0xcc/0x5cc)

Fixes: 0f64478c ("USB: add USB serial mos7720 driver")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Fix NULL-pointer dereference in write() should the device lack the
expected interrupt-out endpoint:

Unable to handle kernel NULL pointer dereference at virtual address 00000054
...
PC is at kobil_write+0x144/0x2a0 [kobil_sct]

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Check for the expected endpoints in attach() and fail loudly if not
present.

Note that failing to do this appears to be benign since da280e34
("USB: keyspan_pda: clean up write-urb busy handling") which prevents a
NULL-pointer dereference in write() by never marking a non-existent
write-urb as free.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>	# < v3.3
Signed-off-by: NJohan Hovold <johan@kernel.org>

Fix NULL-pointer dereference at open should the device lack a bulk-in or
bulk-out endpoint:

Unable to handle kernel NULL pointer dereference at virtual address 00000030
...
PC is at iuu_open+0x78/0x59c [iuu_phoenix]

Fixes: 07c3b1a1 ("USB: remove broken usb-serial num_endpoints
check")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Bind to the interface, but do not register any ports, after having
downloaded the firmware. The device will still disconnect and
re-enumerate, but this way we avoid an error messages from being logged
as part of the process:

io_ti: probe of 1-1.3:1.0 failed with error -5
Signed-off-by: NJohan Hovold <johan@kernel.org>

Cancel the heartbeat work on driver unbind in order to avoid I/O after
disconnect in case the port is held open.

Note that the cancel in release() is still needed to stop the heartbeat
after late probe errors.

Fixes: 26c78daa ("USB: io_ti: Add heartbeat to keep idle EP/416
ports from disconnecting")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

In case a device is left in "boot-mode" we must not register any port
devices in order to avoid a NULL-pointer dereference on open due to
missing endpoints. This could be used by a malicious device to trigger
an OOPS:

Unable to handle kernel NULL pointer dereference at virtual address 00000030
...
[<bf0caa84>] (edge_open [io_ti]) from [<bf0b0118>] (serial_port_activate+0x68/0x98 [usbserial])
[<bf0b0118>] (serial_port_activate [usbserial]) from [<c0470ca4>] (tty_port_open+0x9c/0xe8)
[<c0470ca4>] (tty_port_open) from [<bf0b0da0>] (serial_open+0x48/0x6c [usbserial])
[<bf0b0da0>] (serial_open [usbserial]) from [<c0469178>] (tty_open+0xcc/0x5cc)

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Fix NULL-pointer dereference when clearing halt at open should a
malicious device lack the expected endpoints when in download mode.

Unable to handle kernel NULL pointer dereference at virtual address 00000030
...
[<bf011ed8>] (edge_open [io_ti]) from [<bf000118>] (serial_port_activate+0x68/0x98 [usbserial])
[<bf000118>] (serial_port_activate [usbserial]) from [<c0470ca4>] (tty_port_open+0x9c/0xe8)
[<c0470ca4>] (tty_port_open) from [<bf000da0>] (serial_open+0x48/0x6c [usbserial])
[<bf000da0>] (serial_open [usbserial]) from [<c0469178>] (tty_open+0xcc/0x5cc)

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Fix NULL-pointer dereference when initialising URBs at open should a
non-EPIC device lack a bulk-in or interrupt-in endpoint.

Unable to handle kernel NULL pointer dereference at virtual address 00000028
...
PC is at edge_open+0x24c/0x3e8 [io_edgeport]

Note that the EPIC-device probe path has the required sanity checks so
this makes those checks partially redundant.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Make sure to free the URB transfer buffer in case submission fails (e.g.
due to a disconnect).

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Fix NULL-pointer dereference when clearing halt at open should the device
lack a bulk-out endpoint.

Unable to handle kernel NULL pointer dereference at virtual address 00000030
...
PC is at cyberjack_open+0x40/0x9c [cyberjack]

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Stop Endpoint command can come at any point and we
have no control of that. We should make sure to
handle COMP_STOP on SETUP phase as well, otherwise
urb->actual_length might be set to negative values
in some occasions such as below:

 urb->length = 4;
 build_control_transfer_td_for(urb, ep);

 					stop_endpoint(ep);

COMP_STOP:
	[...]
	urb->actual_length = urb->length - trb->length;

trb->length is 8 for SETUP stage (8 control request
bytes), so actual_length would be set to -4 in this
case.

While doing that, also make sure to use TRB_TYPE
field of the actual TRB instead of matching pointers
to figure out in which stage of the control transfer
we got our completion event.

Cc: <stable@vger.kernel.org>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Intel Apollo Lake also requires XHCI_PME_STUCK_QUIRK.
Adding its PCI ID to quirk.

Cc: <stable@vger.kernel.org>
Signed-off-by: NWan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@intel.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Current abort operation has race.

    xhci_handle_command_timeout()
      xhci_abort_cmd_ring()
        xhci_write_64(CMD_RING_ABORT)
        xhci_handshake(5s)
	  do {
	    check CMD_RING_RUNNING
            udelay(1)
					 ...
					 COMP_CMD_ABORT event
					 COMP_CMD_STOP event
					 xhci_handle_stopped_cmd_ring()
					   restart cmd_ring
                                           CMD_RING_RUNNING become 1 again
	  } while ()
          return -ETIMEDOUT
        xhci_write_64(CMD_RING_ABORT)
        /* can abort random command */

To do abort operation correctly, we have to wait both of COMP_CMD_STOP
event and negation of CMD_RING_RUNNING.

But like above, while timeout handler is waiting negation of
CMD_RING_RUNNING, event handler can restart cmd_ring. So timeout
handler never be notice negation of CMD_RING_RUNNING, and retry of
CMD_RING_ABORT can abort random command (BTW, I guess retry of
CMD_RING_ABORT was workaround of this race).

To fix this race, this moves xhci_handle_stopped_cmd_ring() to
xhci_abort_cmd_ring().  And timeout handler waits COMP_CMD_STOP event.

At this point, timeout handler is owner of cmd_ring, and safely
restart cmd_ring by using xhci_handle_stopped_cmd_ring().

[FWIW, as bonus, this way would be easily extend to add CMD_RING_PAUSE
operation]

[locks edited as patch is rebased on other locking fixes -Mathias]
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This is preparation to fix abort operation race (See "xhci: Fix race
related to abort operation"). To make timeout sleepable, use
delayed_work instead of timer.

[change a newly added pending timer fix to pending work -Mathias]
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In command timer function, xhci_handle_command_timeout(), xhci->lock
is unlocked before call into xhci_abort_cmd_ring(). This might cause
race between the timer function and the event handler.

The xhci_abort_cmd_ring() function sets the CMD_RING_ABORT bit in the
command register and polling it until the setting takes effect. A stop
command ring event might be handled between writing the abort bit and
polling for it. The event handler will restart the command ring, which
causes the failure of polling, and we ever believed that we failed to
stop it.

As a bonus, this also fixes some issues of calling functions without
locking in xhci_handle_command_timeout().

Cc: <stable@vger.kernel.org> # 3.7+
Signed-off-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If we get a command completion event at the same time as the command
timeout work starts on another cpu we might end up aborting the wrong
command.

If the command completion takes the xhci lock before the timeout work, it
will handle the command, pick the next command, mark it as current_cmd, and
re-queue the timeout work. When the timeout work finally gets the lock
It will start aborting the wrong command.

This case can be resolved by checking if the timeout work is pending inside
the timeout function itself. A new timeout work can only be pending if the
command completed and a new command was queued.

If there are no more commands pending then command completion will set
the current_cmd to NULL, which is already handled in the timeout work.

Cc: <stable@vger.kernel.org>
Reported-by: NBaolin Wang <baolin.wang@linaro.org>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>