xhci_stop_device() allocates and issues stop commands for each active endpoint.
This is done with spinlock held and interrupt disabled so we can't sleep during
memory allocation. Use GFP_NOWAIT instead

Regression from commit ddba5cd0
"xhci: Use command structures when queuing commands on the command ring"
for 3.16-rc1

Fixes: ddba5cd0 ("xhci: Use command structures when queuing commands")
Reported-by: NDan Williams <dan.j.williams@intel.com>
Reported-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use one timer to control command timeout.

start/kick the timer every time a command is completed and a
new command is waiting, or a new command is added to a empty list.

If the timer runs out, then tag the current command as "aborted", and
start the xhci command abortion process.

Previously each function that submitted a command had its own timer.
If that command timed out, a new command structure for the
command was created and it was put on a cancel_cmd_list list,
then a pci write to abort the command ring was issued.

when the ring was aborted, it checked if the current command
was the one to be canceled, later when the ring was stopped the
driver got ownership of the TRBs in the command ring,
compared then to the TRBs in the cancel_cmd_list,
and turned them into No-ops.

Now, instead, at timeout we tag the status of the command in the
command queue to be aborted, and start the ring abortion.
Ring abortion stops the command ring and gives control of the
commands to us.
All the aborted commands are now turned into No-ops.

If the ring is already stopped when the command times outs its not possible
to start the ring abortion, in this case the command is turnd to No-op
right away.

All these changes allows us to remove the entire cancel_cmd_list code.

The functions waiting for a command to finish no longer have their own timeouts.
They will wait either until the command completes normally,
or until the whole command abortion is done.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove the per-device command list and handle_cmd_in_cmd_wait_list()
and use the completion and status variables found in the
command structure in the global command list.
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

To create a global command queue we require that each command put on the
command ring is submitted with a command structure.

Functions that queue commands and wait for completion need to allocate a command
before submitting it, and free it once completed. The following command queuing
functions need to be modified.

xhci_configure_endpoint()
xhci_address_device()
xhci_queue_slot_control()
xhci_queue_stop_endpoint()
xhci_queue_new_dequeue_state()
xhci_queue_reset_ep()
xhci_configure_endpoint()

xhci_configure_endpoint() could already be called with a command structure,
and only xhci_check_maxpacket and xhci_check_bandwidth did not do so. These
are changed and a command structure is now required. This change also simplifies
the configure endpoint command completion handling and the "goto bandwidth_change"
handling code can be removed.

In some cases the command queuing function is called in interrupt context.
These commands needs to be allocated atomically, and they can't wait for
completion. These commands will in this patch be freed directly after queuing,
but freeing will be moved to the command completion event handler in a later
patch once we get the global command queue up.(Just so that we won't leak
memory in the middle of the patch set)
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The xHCI driver currently uses a USB core internal field,
udev->lpm_capable, to indicate the xHCI driver knows how to calculate
the LPM timeout values.  If this value is set for the host controller
udev, it means Link PM can be enabled for child devices under that host.

Change the code so the xHCI driver isn't mucking with USB core internal
fields.  Instead, indicate the xHCI driver doesn't support Link PM on
this host by clearing the U1 and U2 exit latencies in the roothub
SuperSpeed Extended Capabilities BOS descriptor.

The code to check for the roothub setting U1 and U2 exit latencies to
zero will also disable LPM for external devices that do that same.  This
was already effectively done with commit
ae8963ad "usb: Don't enable LPM if the
exit latency is zero."  Leave that code in place, so that if a device
sets one exit latency value to zero, but the other is set to a valid
value, LPM is only enabled for the U1 or U2 state that had the valid
value.  This is the same behavior the code had before.

Also, change messages about missing Link PM information from warning
level to info level.  Only print a warning about the first device that
doesn't support LPM, to avoid log spam.  Further, cleanup some
unnecessary line breaks to help people to grep for the error messages.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>

Function xhci_writel() is used to write a 32bit value in xHC registers residing
in MMIO address space. It takes as first argument a pointer to the xhci_hcd
although it does not use it. xhci_writel() internally simply calls writel().
This creates an illusion that xhci_writel() is an xhci specific function that
has to be called in a context where a pointer to xhci_hcd is available.

Remove xhci_writel() wrapper function and replace its calls with calls to
writel() to make the code more straight-forward.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Function xhci_readl() is used to read 32bit xHC registers residing in MMIO
address space. It takes as first argument a pointer to the xhci_hcd although
it does not use it. xhci_readl() internally simply calls readl(). This creates
an illusion that xhci_readl() is an xhci specific function that has to be
called in a context where a pointer to xhci_hcd is available.

Remove the unnecessary xhci_readl() wrapper function and replace its calls to
with calls to readl() to make the code more straightforward.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The usage of USB_CTRL_SET_TIMEOUT in xhci is incorrect.
The definition of USB_CTRL_SET_TIMEOUT is 5000ms. The
input timeout to wait_for_completion_interruptible_timeout
is jiffies. That makes the timeout be longer than what
we want, such as 50s in some platform.

The patch is to use XHCI_CMD_DEFAULT_TIMEOUT instead of
USB_CTRL_SET_TIMEOUT as command completion event timeout.
Signed-off-by: Nxiao jin <jin.xiao@intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

'xhci_del_comp_mod_timer' is local to this file.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The RWE bit of the USB 2.0 PORTPMSC register is supposed to enable
remote wakeup for devices in the lower power link state L1.  It has
nothing to do with the device suspend remote wakeup from L2.  The RWE
bit is designed to be set once (when USB 2.0 LPM is enabled for the
port) and cleared only when USB 2.0 LPM is disabled for the port.

The xHCI bus suspend method was setting the RWE bit erroneously, and the
bus resume method was clearing it.  The xHCI 1.0 specification with
errata up to Aug 12, 2012 says in section 4.23.5.1.1.1 "Hardware
Controlled LPM":

"While Hardware USB2 LPM is enabled, software shall not modify the
HIRDBESL or RWE fields of the USB2 PORTPMSC register..."

If we have previously enabled USB 2.0 LPM for a device, that means when
the USB 2.0 bus is resumed, we violate the xHCI specification by
clearing RWE.  It also means that after a bus resume, the host would
think remote wakeup is disabled from L1 for ports with USB 2.0 Link PM
enabled, which is not what we want.

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 kernel that supported USB 2.0
Link PM.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

When a device signals remote wakeup on a roothub, and the suspend change
bit is set, the host controller driver must not give control back to the
USB core until the port goes back into the active state.

EHCI accomplishes this by waiting in the get port status function until
the PORT_RESUME bit is cleared:

                        /* stop resume signaling */
                        temp &= ~(PORT_RWC_BITS | PORT_SUSPEND | PORT_RESUME);
                        ehci_writel(ehci, temp, status_reg);
                        clear_bit(wIndex, &ehci->resuming_ports);
                        retval = ehci_handshake(ehci, status_reg,
                                        PORT_RESUME, 0, 2000 /* 2msec */);

Similarly, the xHCI host should wait until the port goes into U0, before
passing control up to the USB core.  When the port transitions from the
RExit state to U0, the xHCI driver will get a port status change event.
We need to wait for that event before passing control up to the USB
core.

After the port transitions to the active state, the USB core should time
a recovery interval before it talks to the device.  The length of that
recovery interval is TRSMRCY, 10 ms, mentioned in the USB 2.0 spec,
section 7.1.7.7.  The previous xHCI code (which did not wait for the
port to go into U0) would cause the USB core to violate that recovery
interval.

This bug caused numerous USB device disconnects on remote wakeup under
ChromeOS and a Lynx Point LP xHCI host that takes up to 20 ms to move
from RExit to U0.  ChromeOS is very aggressive about power savings, and
sets the autosuspend_delay to 100 ms, and disables USB persist.

I attempted to replicate this bug with Ubuntu 12.04, but could not.  I
used Ubuntu 12.04 on the same platform, with the same BIOS that the bug
was triggered on ChromeOS with.  I also changed the USB sysfs settings
as described above, but still could not reproduce the bug under Ubuntu.
It may be that ChromeOS userspace triggers this bug through additional
settings.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

If a command on the command ring needs to be cancelled before it is handled
it can be turned to a no-op operation when the ring is stopped.
We want to store the command ring enqueue pointer in the command structure
when the command in enqueued for the cancellation case.

Some commands used to store the command ring dequeue pointers instead of enqueue
(these often worked because enqueue happends to equal dequeue quite often)

Other commands correctly used the enqueue pointer but did not check if it pointed
to a valid trb or a link trb, this caused for example stop endpoint command to timeout in
xhci_stop_device() in about 2% of suspend/resume cases.

This should also solve some weird behavior happening in command cancellation cases.

This patch is based on a patch submitted by Sarah Sharp to linux-usb, but
then forgotten:
    http://marc.info/?l=linux-usb&m=136269803207465&w=2

This patch should be backported to kernels as old as 3.7, that contain
the commit b92cc66c "xHCI: add aborting
command ring function"
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

This patch defines a new trace event, which is called xhci_dbg_quirks
and belongs in the event class xhci_log_msg, and adds tracepoints that
trace the debug messages associated with xHCs' quirks.
Signed-off-by: NXenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

USB 2.1 devices can go into a lower power link state, L1.  When they are
active, they are in the L0 state.  The L1 transition can be purely
driven by software, or some USB host controllers (including some xHCI
1.0 hosts) allow the host hardware to track idleness and automatically
place a port into L1.

The USB 2.1 Link Power Management ECN gives a way for USB 2.1 hubs that
support LPM to report that a port is in L1.  The port status bit 5 will
be set when the port is in L1.  The xHCI host reports the root port as
being in 'U2' when the devices is in L1, and as being in 'U0' when the
port is active (in L0).

Translate the xHCI USB 2.1 link status into the format external hubs
use, and pass the L1 status up to the USB core and tools like lsusb.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The hub control function is *way* too long.  Refactor it into a new
function, and document the side effects of calling that function.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

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>

The USB core hub thread (khubd) is designed with external USB hubs in
mind.  It expects that if a port status change bit is set, the hub will
continue to send a notification through the hub status data transfer.
Basically, it expects hub notifications to be level-triggered.

The xHCI host controller is designed to be edge-triggered on the logical
'OR' of all the port status change bits.  When all port status change
bits are clear, and a new change bit is set, the xHC will generate a
Port Status Change Event.  If another change bit is set in the same port
status register before the first bit is cleared, it will not send
another event.

This means that the hub code may lose port status changes because of
race conditions between clearing change bits.  The user sees this as a
"dead port" that doesn't react to device connects.

The fix is to turn on port polling whenever a new change bit is set.
Once the USB core issues a hub status request that shows that no change
bits are set in any USB ports, turn off port polling.

We can't allow the USB core to poll the roothub for port events during
host suspend because if the PCI host is in D3cold, the port registers
will be all f's.  Instead, stop the port polling timer, and
unconditionally restart it when the host resumes.  If there are no port
change bits set after the resume, the first call to hub_status_data will
disable polling.

This patch should be backported to stable kernels with the first xHCI
support, 2.6.31 and newer, that include the commit
0f2a7930 "USB: xhci: Root hub support."
There will be merge conflicts because the check for HC_STATE_SUSPENDED
was moved into xhci_suspend in 3.8.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Cc: stable@vger.kernel.org

If hot and warm reset fails, or a port remains in the Compliance Mode,
the USB core needs to be able to disable a USB 3.0 port.  Unlike USB 2.0
ports, once the port is placed into the Disabled link state, it will not
report any new device connects.  To get device connect notifications, we
need to put the link into the Disabled state, and then the RxDetect
state.

The xHCI driver needs to atomically clear all change bits on USB 3.0
port disable, so that we get Port Status Change Events for future port
changes.  We could technically do this in the USB core instead of in the
xHCI roothub code, since the port state machine can't advance out of the
disabled state until we set the link state to RxDetect.  However,
external USB 3.0 hubs don't need this code.  They are level-triggered,
not edge-triggered like xHCI, so they will continue to send interrupt
events when any change bit is set.  Therefore it doesn't make sense to
put this code in the USB core.

This patch is part of a series to fix several reports of infinite loops
on device enumeration failure.  This includes John, when he boots with
a USB 3.0 device (Roseweil eusb3 enclosure) attached to his NEC 0.96
host controller.  The fix requires warm reset support, so it does not
make sense to backport this patch to stable kernels without warm reset
support.

This patch should be backported to kernels as old as 3.2, contain the
commit ID 75d7cf72 "usbcore: refine warm
reset logic"
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Reported-by: NJohn Covici <covici@ccs.covici.com>
Cc: stable@vger.kernel.org

Struct usb_hub_descriptor.ss.DeviceRemovable has been defined as __le16
and (__force__ __u16) doesn't need.
Signed-off-by: NLan Tianyu <tianyu.lan@intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

usb/xhci: release xhci->lock during turning on/off usb port's acpi power resource and checking the existence of port's power resource

When setting usb port's acpi power resource, there will be some xhci hub requests.
This will cause dead lock since xhci->lock has been held before setting acpi power
resource in the xhci_hub_control(). The usb_acpi_power_manageable() function might
fall into sleep so release xhci->lock before invoking it.
Signed-off-by: NLan Tianyu <tianyu.lan@intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The comment is a quote of Alan Stern and reflects the data structure
better than the the initial comment.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

drivers/usb/host/xhci.c:1826:14: warning: symbol 'xhci_get_block_size' was not declared. Should it be static?
drivers/usb/host/xhci.c:1844:14: warning: symbol 'xhci_get_largest_overhead' was not declared. Should it be static?
drivers/usb/host/xhci-ring.c:2304:36: warning: context imbalance in 'handle_tx_event' - unexpected unlock
drivers/usb/host/xhci-hub.c:425:6: warning: symbol 'xhci_set_remote_wake_mask' was not declared. Should it be static?
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Upcoming Intel systems will have an ACPI method to control whether a USB
port can be completely powered off.  The implication of powering off a
USB port is that the device and host sees a physical disconnect, and
subsequent port connections and remote wakeups will be lost.

Add a new function, usb_acpi_power_manageable(), that can be used to
find whether the usb port has ACPI power resources that can be used to
power on and off the port on these machines. Also add a new function
called usb_acpi_set_power_state() that controls the port power via these
ACPI methods.

When the USB core calls into the xHCI hub driver to power off a port,
check whether the port can be completely powered off via this new ACPI
mechanism.  If so, call into these new ACPI methods.  Also use the ACPI
methods when the USB core asks to power on a port.
Signed-off-by: NLan Tianyu <tianyu.lan@intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch makes the xHCI roothub code handle the clear PORT_POWER
feature request.  Setting port power is already handled.
Signed-off-by: NLan Tianyu <tianyu.lan@intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch is intended to work around a known issue on the
SN65LVPE502CP USB3.0 re-driver that can delay the negotiation
between a device and the host past the usual handshake timeout.

If that happens on the first insertion, the host controller
port will enter in Compliance Mode and NO port status event will
be generated (as per xHCI Spec) making impossible to detect this
event by software. The port will remain in compliance mode until
a warm reset is applied to it.

As a result of this, the port will seem "dead" to the user and no
device connections or disconnections will be detected.

For solving this, the patch creates a timer which polls every 2
seconds the link state of each host controller's port (this
by reading the PORTSC register) and recovers the port by issuing a
Warm reset every time Compliance mode is detected.

If a xHC USB3.0 port has previously entered to U0, the compliance
mode issue will NOT occur only until system resumes from
sleep/hibernate, therefore, the compliance mode timer is stopped
when all xHC USB 3.0 ports have entered U0. The timer is initialized
again after each system resume.

Since the issue is being caused by a piece of hardware, the timer
will be enabled ONLY on those systems that have the SN65LVPE502CP
installed (this patch uses DMI strings for detecting those systems)
therefore making this patch to act as a quirk (XHCI_COMP_MODE_QUIRK
has been added to the xhci stack).

This patch applies for these systems:
Vendor: Hewlett-Packard. System Models: Z420, Z620 and Z820.

This patch should be backported to kernels as old as 3.2, as that was
the first kernel to support warm reset.  The kernels will need to
contain both commit 10d674a8 "USB: When
hot reset for USB3 fails, try warm reset" and commit
8bea2bd3 "usb: Add support for root hub
port status CAS".  The first patch add warm reset support, and the
second patch modifies the USB core to issue a warm reset when the port
is in compliance mode.
Signed-off-by: NAlexis R. Cortes <alexis.cortes@ti.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

Some xHCI host controllers may have optional support for Latency
Tolerance Messaging (LTM).  This allows USB 3.0 devices that support LTM
to pass information about how much latency they can tolerate to the xHC.
A PCI xHCI host will use this information to update the PCI Latency
Tolerance Request (LTR) info.  The goal of this is to gather latency
information for the system, to enable hardware-driven C states, and the
shutting down of PLLs.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The host controller port status register supports CAS (Cold Attach
Status) bit. This bit could be set when USB3.0 device is connected
when system is in Sx state. When the system wakes to S0 this port
status with CAS bit is reported and this port can't be used by any
device.

When CAS bit is set the port should be reset by warm reset. This
was not supported by xhci driver.

The issue was found when pendrive was connected to suspended
platform. The link state of "Compliance Mode" was reported together
with CAS bit. This link state was also not supported by xhci and
core/hub.c.

The CAS bit is defined only for xhci root hub port and it is
not supported on regular hubs. The link status is used to force
warm reset on port. Make the USB core issue a warm reset when port
is in ether the 'inactive' or 'compliance mode'. Change the xHCI driver
to report 'compliance mode' when the CAS is set. This force warm reset
on the root hub port.

This patch should be backported to stable kernels as old as 3.2, that
contain the commit 10d674a8 "USB: When
hot reset for USB3 fails, try warm reset."
Signed-off-by: NStanislaw Ledwon <staszek.ledwon@linux.intel.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Acked-by: NAndiry Xu <andiry.xu@amd.com>
Cc: stable@vger.kernel.org

USB 3.0 hubs can be put into a mode where the hub can automatically
request that the link go into a deeper link power state after the link
has been idle for a specified amount of time.  Each of the new USB 3.0
link states (U1 and U2) have their own timeout that can be programmed
per port.

Change the xHCI roothub emulation code to handle the request to set the
U1 and U2 timeouts.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This commit adds a bit-array to xhci bus_state for keeping track of
which ports are undergoing a resume transition. If any of the bits
are set when xhci_hub_status_data() is called, the routine will return
a non-zero value even if no ports have any status changes pending.
This will allow usbcore to handle races between root-hub suspend and
port wakeup.

This patch should be backported to kernels as old as 3.4, that contain
the commit 879d38e6 "USB: fix race
between root-hub suspend and remote wakeup".
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: stable@vger.kernel.org

USB 3.0 hubs have a different remote wakeup policy than USB 2.0 hubs.
USB 2.0 hubs, once they have remote wakeup enabled, will always send
remote wakes when anything changes on a port.

However, USB 3.0 hubs have a per-port remote wake up policy that is off
by default.  The Set Feature remote wake mask can be changed for any
port, enabling remote wakeup for a connect, disconnect, or overcurrent
event, much like EHCI and xHCI host controller "wake on" port status
bits.  The bits are cleared to zero on the initial hub power on, or
after the hub has been reset.

Without this patch, when a USB 3.0 hub gets suspended, it will not send
a remote wakeup on device connect or disconnect.  This would show up to
the user as "dead ports" unless they ran lsusb -v (since newer versions
of lsusb use the sysfs files, rather than sending control transfers).

Change the hub driver's suspend method to enable remote wake up for
disconnect, connect, and overcurrent for all ports on the hub.  Modify
the xHCI driver's roothub code to handle that request, and set the "wake
on" bits in the port status registers accordingly.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The code to set the device removable bits in the USB 2.0 roothub
descriptor was accidentally looking at the USB 3.0 port registers
instead of the USB 2.0 registers.  This can cause an oops if there are
more USB 2.0 registers than USB 3.0 registers.

This should be backported to kernels as old as 2.6.39, that contain the
commit 4bbb0ace "xhci: Return a USB 3.0
hub descriptor for USB3 roothub."
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

xhci-hub used some numerical values for initialisation of root hub
descriptors. #define values are addded in usb 2.0 hub specification
file and these values are used for root hub characteristics
initialisation.

Also use some #defines in places where magic numbers are being used.
Signed-off-by: NAman Deep <amandeep3986@gmail.com>
Acked-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

To fix this build error on ARM:

drivers/usb/host/xhci-hub.c: In function 'xhci_stop_device':
drivers/usb/host/xhci-hub.c:261: error: 'GFP_NOIO' undeclared (first use in this function)
make[4]: *** [drivers/usb/host/xhci-hub.o] Error 1
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

To add USB 3.0 link power management (LPM), we need to know what the U1
and U2 exit latencies are for the xHCI host controller.  External USB 3.0
hubs report these values through the SuperSpeed Capabilities descriptor in
the BOS descriptor.  Make the USB 3.0 roothub for the xHCI host behave
like an external hub and return the BOS descriptors.

The U1 and U2 exit latencies will vary across each host controller, so we
need to dynamically fill those values in by reading the exit latencies out
of the xHC registers.  Make the roothub code in the USB core handle
hub_control() returning the length of the data copied.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

If the device pass the USB2 software LPM and the host supports hardware
LPM, enable hardware LPM for the device to let the host decide when to
put the link into lower power state.

If hardware LPM is enabled for a port and driver wants to put it into
suspend, it must first disable hardware LPM, resume the port into U0,
and then suspend the port.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Introduce xhci_test_and_clear_bit() to clear RWC bit in PORTSC register.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Introduce xhci_set_link_state() to remove redundant codes.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Sometimes, when a USB 3.0 device is disconnected, the Intel Panther
Point xHCI host controller will report a link state change with the
state set to "SS.Inactive".  This causes the xHCI host controller to
issue a warm port reset, which doesn't finish before the USB core times
out while waiting for it to complete.

When the warm port reset does complete, and the xHC gives back a port
status change event, the xHCI driver kicks khubd.  However, it fails to
set the bit indicating there is a change event for that port because the
logic in xhci-hub.c doesn't check for the warm port reset bit.

After that, the warm port status change bit is never cleared by the USB
core, and the xHC stops reporting port status change bits.  (The xHCI
spec says it shouldn't report more port events until all change bits are
cleared.) This means any port changes when a new device is connected
will never be reported, and the port will seem "dead" until the xHCI
driver is unloaded and reloaded, or the computer is rebooted.  Fix this
by making the xHCI driver set the port change bit when a warm port reset
change bit is set.

A better solution would be to make the USB core handle warm port reset
in differently, merging the current code with the standard port reset
code that does an incremental backoff on the timeout, and tries to
complete the port reset two more times before giving up.  That more
complicated fix will be merged next window, and this fix will be
backported to stable.

This should be backported to kernels as old as 3.0, since that was the
first kernel with commit a11496eb ("xHCI: warm reset support").
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The "port" field in xhci_virt_dev stores the port number associated with
one of the two xHCI split roothubs, not the unique port number the xHCI
hardware uses.  Since we'll need to store the real hardware port number in
future patches, rename this field to "fake_port".
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>