PREPARE_[DELAYED_]WORK() are being phased out.  They have few users
and a nasty surprise in terms of reentrancy guarantee as workqueue
considers work items to be different if they don't have the same work
function.

usb_hub->init_work is multiplexed with multiple work functions;
however, the work item is never queued while in-flight, so we can
simply use INIT_DELAYED_WORK() before each queueing.

It would probably be best to route this with other related updates
through the workqueue tree.

Lightly tested.

v2: Greg and Alan confirm that the work item is never queued while
    in-flight.  Simply use INIT_DELAYED_WORK().
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: linux-usb@vger.kernel.org

Commit 9df89d85 "usbcore: set
lpm_capable field for LPM capable root hubs" was created under the
assumption that all USB host controllers should have USB 3.0 Link PM
enabled for all devices under the hosts.

Unfortunately, that's not the case.  The xHCI driver relies on knowledge
of the host hardware scheduler to calculate the LPM U1/U2 timeout
values, and it only sets lpm_capable to one for Intel host controllers
(that have the XHCI_LPM_SUPPORT quirk set).

When LPM is enabled for some Fresco Logic hosts, it causes failures with
a AgeStar 3UBT USB 3.0 hard drive dock:

Jan 11 13:59:03 sg-laptop kernel: usb 3-1: new SuperSpeed USB device number 2 using xhci_hcd
Jan 11 13:59:03 sg-laptop kernel: usb 3-1: Set SEL for device-initiated U1 failed.
Jan 11 13:59:08 sg-laptop kernel: usb 3-1: Set SEL for device-initiated U2 failed.
Jan 11 13:59:08 sg-laptop kernel: usb-storage 3-1:1.0: USB Mass Storage device detected
Jan 11 13:59:08 sg-laptop mtp-probe[613]: checking bus 3, device 2: "/sys/devices/pci0000:00/0000:00:1c.3/0000:04:00.0/usb3/3-1"
Jan 11 13:59:08 sg-laptop mtp-probe[613]: bus: 3, device: 2 was not an MTP device
Jan 11 13:59:08 sg-laptop kernel: scsi6 : usb-storage 3-1:1.0
Jan 11 13:59:13 sg-laptop kernel: usb 3-1: Set SEL for device-initiated U1 failed.
Jan 11 13:59:18 sg-laptop kernel: usb 3-1: Set SEL for device-initiated U2 failed.
Jan 11 13:59:18 sg-laptop kernel: usbcore: registered new interface driver usb-storage
Jan 11 13:59:40 sg-laptop kernel: usb 3-1: reset SuperSpeed USB device number 2 using xhci_hcd
Jan 11 13:59:41 sg-laptop kernel: usb 3-1: device descriptor read/8, error -71
Jan 11 13:59:41 sg-laptop kernel: usb 3-1: reset SuperSpeed USB device number 2 using xhci_hcd
Jan 11 13:59:46 sg-laptop kernel: usb 3-1: device descriptor read/8, error -110
Jan 11 13:59:46 sg-laptop kernel: scsi 6:0:0:0: Device offlined - not ready after error recovery
Jan 11 13:59:46 sg-laptop kernel: usb 3-1: USB disconnect, device number 2

lspci for the affected host:

04:00.0 0c03: 1b73:1000 (rev 04) (prog-if 30 [XHCI])
        Subsystem: 1043:1039
        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
        Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
        Latency: 0, Cache Line Size: 64 bytes
        Interrupt: pin A routed to IRQ 19
        Region 0: Memory at dd200000 (32-bit, non-prefetchable) [size=64K]
        Capabilities: [50] Power Management version 3
                Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold-)
                Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
        Capabilities: [68] MSI: Enable- Count=1/1 Maskable- 64bit+
                Address: 0000000000000000  Data: 0000
        Capabilities: [80] Express (v1) Endpoint, MSI 00
                DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <2us, L1 <32us
                        ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ FLReset-
                DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
                        RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+
                        MaxPayload 128 bytes, MaxReadReq 512 bytes
                DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr- TransPend-
                LnkCap: Port #0, Speed 2.5GT/s, Width x1, ASPM L0s L1, Latency L0 unlimited, L1 unlimited
                        ClockPM- Surprise- LLActRep- BwNot-
                LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk+
                        ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
                LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
        Kernel driver in use: xhci_hcd
        Kernel modules: xhci_hcd

The commit was backported to stable kernels, and will need to be
reverted there as well.
Signed-off-by: NSarah Sharp <sarah.a.sharp@intel.com>
Reported-by: NSergey Galanov <sergey.e.galanov@gmail.com>
Cc: stable@vger.kernel.org

When we are doing compliance test with xHCI, we found that if we
enable CONFIG_USB_SUSPEND and plug in a bad device which causes
over-current condition to the root port, software will not be noticed.
The reason is that current code don't set hub->change_bits in
hub_activate() when over-current happens, and then hub_events() will
not check the port status because it thinks nothing changed.
If CONFIG_USB_SUSPEND is disabled, the interrupt pipe of the hub will
report the change and set hub->event_bits, and then hub_events() will
check what events happened.In this case over-current can be detected.
Signed-off-by: NShen Guang <shenguang10@gmail.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Acked-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NRahul Bedarkar <rahulbedarkar89@gmail.com>
Acked-by: NRandy Dunlap <rdunlap@infradead.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is a race in the hub driver between hub_disconnect() and
recursively_mark_NOTATTACHED().  This race can be triggered if the
driver is unbound from a device at the same time as the bus's root hub
is removed.  When the race occurs, it can cause an oops:

BUG: unable to handle kernel NULL pointer dereference at 0000015c
IP: [<c16d5fb0>] recursively_mark_NOTATTACHED+0x20/0x60
Call Trace:
 [<c16d5fc4>] recursively_mark_NOTATTACHED+0x34/0x60
 [<c16d5fc4>] recursively_mark_NOTATTACHED+0x34/0x60
 [<c16d5fc4>] recursively_mark_NOTATTACHED+0x34/0x60
 [<c16d5fc4>] recursively_mark_NOTATTACHED+0x34/0x60
 [<c16d6082>] usb_set_device_state+0x92/0x120
 [<c16d862b>] usb_disconnect+0x2b/0x1a0
 [<c16dd4c0>] usb_remove_hcd+0xb0/0x160
 [<c19ca846>] ? _raw_spin_unlock_irqrestore+0x26/0x50
 [<c1704efc>] ehci_mid_remove+0x1c/0x30
 [<c1704f26>] ehci_mid_stop_host+0x16/0x30
 [<c16f7698>] penwell_otg_work+0xd28/0x3520
 [<c19c945b>] ? __schedule+0x39b/0x7f0
 [<c19cdb9d>] ? sub_preempt_count+0x3d/0x50
 [<c125e97d>] process_one_work+0x11d/0x3d0
 [<c19c7f4d>] ? mutex_unlock+0xd/0x10
 [<c125e0e5>] ? manage_workers.isra.24+0x1b5/0x270
 [<c125f009>] worker_thread+0xf9/0x320
 [<c19ca846>] ? _raw_spin_unlock_irqrestore+0x26/0x50
 [<c125ef10>] ? rescuer_thread+0x2b0/0x2b0
 [<c1264ac4>] kthread+0x94/0xa0
 [<c19d0f77>] ret_from_kernel_thread+0x1b/0x28
 [<c1264a30>] ? kthread_create_on_node+0xc0/0xc0

One problem is that recursively_mark_NOTATTACHED() uses the intfdata
value and hub->hdev->maxchild while hub_disconnect() is clearing them.
Another problem is that it uses hub->ports[i] while the port device is
being released.

To fix this race, we need to hold the device_state_lock while
hub_disconnect() changes the values.  (Note that usb_disconnect()
and hub_port_connect_change() already acquire this lock at similar
critical times during a USB device's life cycle.)  We also need to
remove the port devices after maxchild has been set to 0, instead of
before.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Reported-by: N"Du, Changbin" <changbinx.du@intel.com>
Tested-by: N"Du, Changbin" <changbinx.du@intel.com>
CC: <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

CONFIG_USB_DEBUG is going away, so remove the few places in the USB core
that relied on them.

This means that we always now do the "debug" checks for every urb
submitted, which is a good idea, as who knows how many driver bugs we
have been ignoring when people forget to enable this option.  Also, with
the overall speed of USB, doing these extra checks should not cause any
additional overhead.

Also, no longer announce all devices being added to the system if
CONFIG_USB_DEBUG is enabled, as it's not going to be around much longer.
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Change the default enumeration scheme for xhci attached non-SuperSpeed
devices from:

   Reset
   SetAddress [xhci address-device BSR = 0]
   GetDescriptor(8)
   GetDescriptor(18)

...to:

   Reset
   [xhci address-device BSR = 1]
   GetDescriptor(64)
   Reset
   SetAddress [xhci address-device BSR = 0]
   GetDescriptor(18)

...as some devices misbehave when encountering a SetAddress command
prior to GetDescriptor.  There are known legacy devices that require
this scheme, but testing has found at least one USB3 device that fails
enumeration when presented with this ordering.  For now, follow the ehci
case and enable 'new scheme' by default for non-SuperSpeed devices.

To support this enumeration scheme on xhci the AddressDevice operation
needs to be performed twice.  The first instance of the command enables
the HC's device and slot context info for the device, but omits sending
the device a SetAddress command (BSR == block set address request).
Then, after GetDescriptor completes, follow up with the full
AddressDevice+SetAddress operation.

As mentioned before, this ordering of events with USB3 devices causes an
extra state transition to be exposed to xhci.  Previously USB3 devices
would transition directly from 'enabled' to 'addressed' and never need
to underrun responses to 'get descriptor'. We do see the 64-byte
descriptor fetch the correct data, but the following 18-byte descriptor
read after the reset gets:

bLength            = 0
bDescriptorType    = 0
bcdUSB             = 0
bDeviceClass       = 0
bDeviceSubClass    = 0
bDeviceProtocol    = 0
bMaxPacketSize0    = 9

instead of:

bLength            = 12
bDescriptorType    = 1
bcdUSB             = 300
bDeviceClass       = 0
bDeviceSubClass    = 0
bDeviceProtocol    = 0
bMaxPacketSize0    = 9

which results in the discovery process looping until falling back to
'old scheme' enumeration.
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Reported-by: NDavid Moore <david.moore@gmail.com>
Suggested-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

There is no need to skip querying the config and string descriptors for
unauthorized WUSB devices when usb_new_device is called.  It is allowed
by WUSB spec.  The only action that needs to be delayed until
authorization time is the set config.  This change allows user mode
tools to see the config and string descriptors earlier in enumeration
which is needed for some WUSB devices to function properly on Android
systems.  It also reduces the amount of divergent code paths needed
for WUSB devices.
Signed-off-by: NThomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds a check for USB_STATE_NOTATTACHED to the
hub_port_warm_reset_required() workaround for ports that end up in
Compliance Mode in hub_events() when trying to decide which reset
function to use. Trying to call usb_reset_device() with a NOTATTACHED
device will just fail and leave the port broken.
Signed-off-by: NJulius Werner <jwerner@chromium.org>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since DEVICE_ACPI_HANDLE() is now literally identical to
ACPI_HANDLE(), replace it with the latter everywhere and drop its
definition from include/acpi.h.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove a few extra lines and make it clear that all implementations
disable the port by sharing the same line of code.
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This patch adds the Port Reset Change flag to the set of bits that are
preemptively cleared on init/resume of a hub. In theory this bit should
never be set unexpectedly... in practice it can still happen if BIOS,
SMM or ACPI code plays around with USB devices without cleaning up
correctly. This is especially dangerous for XHCI root hubs, which don't
generate any more Port Status Change Events until all change bits are
cleared, so this is a good precaution to have (similar to how it's
already done for the Warm Port Reset Change flag).
Signed-off-by: NJulius Werner <jwerner@chromium.org>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some usb3 devices falsely claim they support usb2 hardware Link PM
when connected to a usb2 port. We only trust hardwired devices
or devices with the later BESL LPM support to be LPM enabled as default.

[Note: Sarah re-worked the original patch to move the code into the USB
core, and updated it to check whether the USB device supports BESL,
instead of checking if the xHCI port it's connected to supports BESL
encoding.]

This patch should be backported to kernels as old as 3.11, that
contain the commit a558ccdc "usb: xhci:
add USB2 Link power management BESL support".  Without this fix, some
USB 3.0 devices will not enumerate or work properly under USB 2.0 ports
on Haswell-ULT systems.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

How it's supposed to work:
--------------------------

USB 2.0 Link PM is a lower power state that some newer USB 2.0 devices
support.  USB 3.0 devices certified by the USB-IF are required to
support it if they are plugged into a USB 2.0 only port, or a USB 2.0
cable is used.  USB 2.0 Link PM requires both a USB device and a host
controller that supports USB 2.0 hardware-enabled LPM.

USB 2.0 Link PM is designed to be enabled once by software, and the host
hardware handles transitions to the L1 state automatically.  The premise
of USB 2.0 Link PM is to be able to put the device into a lower power
link state when the bus is idle or the device NAKs USB IN transfers for
a specified amount of time.

...but hardware is broken:
--------------------------

It turns out many USB 3.0 devices claim to support USB 2.0 Link PM (by
setting the LPM bit in their USB 2.0 BOS descriptor), but they don't
actually implement it correctly.  This manifests as the USB device
refusing to respond to transfers when it is plugged into a USB 2.0 only
port under the Haswell-ULT/Lynx Point LP xHCI host.

These devices pass the xHCI driver's simple test to enable USB 2.0 Link
PM, wait for the port to enter L1, and then bring it back into L0.  They
only start to break when L1 entry is interleaved with transfers.

Some devices then fail to respond to the next control transfer (usually
a Set Configuration).  This results in devices never enumerating.

Other mass storage devices (such as a later model Western Digital My
Passport USB 3.0 hard drive) respond fine to going into L1 between
control transfers.  They ACK the entry, come out of L1 when the host
needs to send a control transfer, and respond properly to those control
transfers.  However, when the first READ10 SCSI command is sent, the
device NAKs the data phase while it's reading from the spinning disk.
Eventually, the host requests to put the link into L1, and the device
ACKs that request.  Then it never responds to the data phase of the
READ10 command.  This results in not being able to read from the drive.

Some mass storage devices (like the Corsair Survivor USB 3.0 flash
drive) are well behaved.  They ACK the entry into L1 during control
transfers, and when SCSI commands start coming in, they NAK the requests
to go into L1, because they need to be at full power.

Not all USB 3.0 devices advertise USB 2.0 link PM support.  My Point
Grey USB 3.0 webcam advertises itself as a USB 2.1 device, but doesn't
have a USB 2.0 BOS descriptor, so we don't enable USB 2.0 Link PM.  I
suspect that means the device isn't certified.

What do we do about it?
-----------------------

There's really no good way for the kernel to test these devices.
Therefore, the kernel needs to disable USB 2.0 Link PM by default, and
distros will have to enable it by writing 1 to the sysfs file
/sys/bus/usb/devices/../power/usb2_hardware_lpm.  Rip out the xHCI Link
PM test, since it's not sufficient to detect these buggy devices, and
don't automatically enable LPM after the device is addressed.

This patch should be backported to kernels as old as 3.11, that
contain the commit a558ccdc "usb: xhci:
add USB2 Link power management BESL support".  Without this fix, some
USB 3.0 devices will not enumerate or work properly under USB 2.0 ports
on Haswell-ULT systems.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

Before the USB core resets a device, we need to disable the L1 timeout
for the roothub, if USB 2.0 Link PM is enabled.  Otherwise the port may
transition into L1 in between descriptor fetches, before we know if the
USB device descriptors changed.  LPM will be re-enabled after the
full device descriptors are fetched, and we can confirm the device still
supports USB 2.0 LPM after the reset.

We don't need to wait for the USB device to exit L1 before resetting the
device, since the xHCI roothub port diagrams show a transition to the
Reset state from any of the Ux states (see Figure 34 in the 2012-08-14
xHCI specification update).

This patch should be backported to kernels as old as 3.2, that contain
the commit 65580b43 "xHCI: set USB2
hardware LPM".  That was the first commit to enable USB 2.0
hardware-driven Link Power Management.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

Signed-off-by: NMatthias Beyer <mail@beyermatthias.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

including:

- removing of trailing whitespace
- removing spaces before array indexing (foo [] to foo[])
- reindention of a switch-case block
- spaces to tabs
Signed-off-by: NMatthias Beyer <mail@beyermatthias.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

These aren't necessary after switch and if blocks.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

usb_disconnect() no longer acquires usb_bus_list_lock, so update its
comment to that effect.
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Set SEL control urbs cannot be sent to a device in unconfigured state.
This patch adds a check in usb_req_set_sel() to ensure the usb device's
state is USB_STATE_CONFIGURED.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Reported-by: NMartin MOKREJS <mmokrejs@gmail.com>
Suggested-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

In the bos usb_ss_cap_descriptor structure, bU2DevExitLat is of type __le16.
This value is used as it is, without being first converted to the CPU
byteorder, for the setup of usb device's usb3_lpm_parameters.
This patch fixes that by converting bU2DevExitLat field to the CPU byteorder
before the assignmenment to [udev/hub]_u2_del variables.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch sets the lpm_capable field for root hubs with LPM capabilities.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Reported-by: NMartin MOKREJS <mmokrejs@gmail.com>
Suggested-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch fixes the incorrect assignment of a variable with type 'le16'
to a variable with type 'unsigned int'.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In usb_reset_and_verify_device(), hub_port_init() allocates a new bos
descriptor to hold the value read by the device. The new bos descriptor
has to be compared with the old one in order to figure out if device 's
firmware has changed in which case the device has to be reenumerated.
In the original code, none of the two descriptors was deallocated leading
to memory leaks.

This patch compares the old bos descriptor with the new one to detect change
in firmware and releases the newly allocated bos descriptor to prevent memory
leak.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Reported-by: NMartin MOKREJS <mmokrejs@gmail.com>
Tested-by: NMartin MOKREJS <mmokrejs@gmail.com>
Suggested-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

After successful initialization hub->descriptor->bNbrPorts and
hub->hdev->maxchild are equal, but using hub->hdev->maxchild is
preferred because that value is explicitly used for initialization
of hub->ports[].
Signed-off-by: NKrzysztof Mazur <krzysiek@podlesie.net>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Ignoring usb_hub_create_port_device() errors cause later NULL pointer
deference when uninitialized hub->ports[i] entries are dereferenced
after port memory allocation error.
Signed-off-by: NKrzysztof Mazur <krzysiek@podlesie.net>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If the hub_configure() fails after setting the hdev->maxchild
the hub->ports might be NULL or point to uninitialized kzallocated
memory causing NULL pointer dereference in hub_quiesce() during cleanup.

Now after such error the hdev->maxchild is set to 0 to avoid cleanup
of uninitialized ports.
Signed-off-by: NKrzysztof Mazur <krzysiek@podlesie.net>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The pm qos NO_POWER_OFF flag is checked twice during usb device suspend
to see if the usb port power off condition is met. This is redundant and
also will prevent the port from being powered off if the NO_POWER_OFF
flag is changed to 1 from 0 after the device was already suspended.

More detail in the following link.
	http://marc.info/?l=linux-usb&m=136543949130865&w=2

This patch should be backported to kernels as old as 3.7, that
contain the commit f7ac7787 "usb/acpi:
Use ACPI methods to power off ports."
Signed-off-by: NLan Tianyu <tianyu.lan@intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

The hub driver's usb_port_suspend() routine doesn't handle errors
related to Link Power Management properly.  It always returns failure,
it doesn't try to clean up the wakeup setting, (in the case of system
sleep) it doesn't try to go ahead with the port suspend regardless,
and it doesn't try to apply the new power-off mechanism.

This patch fixes these problems.

Note: Sarah fixed this patch to apply against 3.11, since the original
commit (4fae6f0f "USB: handle LPM errors
during device suspend correctly") called usb_disable_remote_wakeup,
which won't be added until 3.12.

This patch should be backported to kernels as old as 3.5, that
contain the commit 8306095f "USB:
Disable USB 3.0 LPM in critical sections.".  There will be merge
conflicts, since LTM wasn't added until 3.6.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

When building the htmldocs (in verbose mode), scripts/kernel-doc reports the
following type of warnings:

Warning(drivers/usb/core/usb.c:76): No description found for return value of
'usb_find_alt_setting'

Fix them by:
- adding some missing descriptions of return values
- using "Return" sections for those descriptions
Signed-off-by: NYacine Belkadi <yacine.belkadi.1@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The hub driver's usb_port_suspend() routine doesn't handle errors
related to Link Power Management properly.  It always returns failure,
it doesn't try to clean up the wakeup setting, (in the case of system
sleep) it doesn't try to go ahead with the port suspend regardless,
and it doesn't try to apply the new power-off mechanism.

This patch fixes these problems.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Acked-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The hub driver is inconsistent in its organization of code for
enabling and disabling remote wakeup.  There is a special routine to
disable wakeup for SuperSpeed devices but not for slower devices, and
there is no special routine to enable wakeup.

This patch refactors the code.  It renames and changes the existing
function to make it handle both SuperSpeed and non-SuperSpeed devices,
and it adds a corresponding routine to enable remote wakeup.  It also
changes the speed determination to look at the device's speed rather
than the speed of the parent hub -- this shouldn't make any difference
because a SuperSpeed device always has to be attached to a SuperSpeed
hub and conversely.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch simplifies the interface presented by usb_get_status().
Instead of forcing callers to check for the proper data length and
convert the status value to host byte order, the function will now
do these things itself.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The USB hub driver's event handler contains a check to catch SuperSpeed
devices that transitioned into the SS.Inactive state and tries to fix
them with a reset. It decides whether to do a plain hub port reset or
call the usb_reset_device() function based on whether there was a device
attached to the port.

However, there are device/hub combinations (found with a JetFlash
Transcend mass storage stick (8564:1000) on the root hub of an Intel
LynxPoint PCH) which can transition to the SS.Inactive state on
disconnect (and stay there long enough for the host to notice). In this
case, above-mentioned reset check will call usb_reset_device() on the
stale device data structure. The kernel will send pointless LPM control
messages to the no longer connected device address and can even cause
several 5 second khubd stalls on some (buggy?) host controllers, before
finally accepting the device's fate amongst a flurry of error messages.

This patch makes the choice of reset dependent on the port status that
has just been read from the hub in addition to the existence of an
in-kernel data structure for the device, and only proceeds with the more
extensive reset if both are valid.
Signed-off-by: NJulius Werner <jwerner@chromium.org>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The USB hub driver's event handler contains a check to catch SuperSpeed
devices that transitioned into the SS.Inactive state and tries to fix
them with a reset. It decides whether to do a plain hub port reset or
call the usb_reset_device() function based on whether there was a device
attached to the port.

However, there are device/hub combinations (found with a JetFlash
Transcend mass storage stick (8564:1000) on the root hub of an Intel
LynxPoint PCH) which can transition to the SS.Inactive state on
disconnect (and stay there long enough for the host to notice). In this
case, above-mentioned reset check will call usb_reset_device() on the
stale device data structure. The kernel will send pointless LPM control
messages to the no longer connected device address and can even cause
several 5 second khubd stalls on some (buggy?) host controllers, before
finally accepting the device's fate amongst a flurry of error messages.

This patch makes the choice of reset dependent on the port status that
has just been read from the hub in addition to the existence of an
in-kernel data structure for the device, and only proceeds with the more
extensive reset if both are valid.
Signed-off-by: NJulius Werner <jwerner@chromium.org>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This patch removes a redundant nested "#ifdef CONFIG_PM" from the hub
driver.  It also adds a label to the "#endif" line corresponding to
the outer "#ifdef CONFIG_PM".
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Control transfers have both IN and OUT (or SETUP) packets, so when
clearing TT buffers for a control transfer it's necessary to send
two HUB_CLEAR_TT_BUFFER requests to the hub.
Signed-off-by: NWilliam Gulland <wgulland@google.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The hub driver was recently changed to use "global" suspend for system
suspend transitions on non-SuperSpeed buses.  This means that we don't
suspend devices individually by setting the suspend feature on the
upstream hub port; instead devices all go into suspend automatically
when the root hub stops transmitting packets.  The idea was to save
time and to avoid certain kinds of wakeup races.

Now it turns out that many hubs are buggy; they don't relay wakeup
requests from a downstream port to their upstream port if the
downstream port's suspend feature is not set (depending on the speed
of the downstream port, whether or not the hub is enabled for remote
wakeup, and possibly other factors).

We can't have hubs dropping wakeup requests.  Therefore this patch
goes partway back to the old policy: It sets the suspend feature for a
port if the device attached to that port or any of its descendants is
enabled for wakeup.  People will still be able to benefit from the
time savings if they don't care about wakeup and leave it disabled on
all their devices.

In order to accomplish this, the patch adds a new field to the usb_hub
structure: wakeup_enabled_descendants is a count of how many devices
below a suspended hub are enabled for remote wakeup.  A corresponding
new subroutine determines the number of wakeup-enabled devices at or
below an arbitrary suspended USB device.

This should be applied to the 3.10 stable kernel.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: NToralf Förster <toralf.foerster@gmx.de>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

usb_hub_to_struct_hub() can return NULL in some unlikely cases.
Add checks where appropriate, or pass the hub pointer as an additional
argument if it's known to be valid.

The places it makes sense to check usb_hub_to_struct_hub()
are picked based on feedback from Alan Stern.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch (as1675) removes the CONFIG_USB_SUSPEND option, essentially
replacing it everywhere with CONFIG_PM_RUNTIME (except for one place
in hub.c, where it is replaced with CONFIG_PM because the code needs
to be used in both runtime and system PM).  The net result is code
shrinkage and simplification.

There's very little point in keeping CONFIG_USB_SUSPEND because almost
everybody enables it.  The few that don't will find that the usbcore
module has gotten somewhat bigger and they will have to take active
measures if they want to prevent hubs from being runtime suspended.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
CC: Peter Chen <peter.chen@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>