Non-static xHCI driver symbols should start with the "xhci_" prefix, in
order to avoid namespace pollution.  Rename the "handshake" function to
"xhci_handshake".
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: NBen Hutchings <ben@decadent.org.uk>

When a device with an isochronous endpoint is behind a hub plugged into
the Intel Panther Point xHCI host controller, and the driver submits
multiple frames per URB, the xHCI driver will set the Block Event
Interrupt (BEI) flag on all but the last TD for the URB.  This causes
the host controller to place an event on the event ring, but not send an
interrupt.  When the last TD for the URB completes, BEI is cleared, and
we get an interrupt for the whole URB.

However, under a Panther Point xHCI host controller, if the parent hub
is unplugged when one or more events from transfers with BEI set are on
the event ring, a port status change event is placed on the event ring,
but no interrupt is generated.  This means URBs stop completing, and the
USB device disconnect is not noticed.  Something like a USB headset will
cause mplayer to hang when the device is disconnected.

If another transfer is sent (such as running `sudo lsusb -v`), the next
transfer event seems to "unstick" the event ring, the xHCI driver gets
an interrupt, and the disconnect is reported to the USB core.

The fix is not to use the BEI flag under the Panther Point xHCI host.
This will impact power consumption and system responsiveness, because
the xHCI driver will receive an interrupt for every frame in all
isochronous URBs instead of once per URB.

Intel chipset developers confirm that this bug will be hit if the BEI
flag is used on any endpoint, not just ones that are behind a hub.

This patch should be backported to kernels as old as 3.0, that contain
the commit 69e848c2 "Intel xhci: Support
EHCI/xHCI port switching."
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

The patch is used to cancel command when the command isn't
acknowledged and a timeout occurs.

This patch should be backported to kernels as old as 3.0, that contain
the commit 7ed603ec "xhci: Add an
assertion to check for virt_dev=0 bug." That commit papers over a NULL
pointer dereference, and this patch fixes the underlying issue that
caused the NULL pointer dereference.
Signed-off-by: NElric Fu <elricfu1@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: NMiroslav Sabljic <miroslav.sabljic@avl.com>
Cc: stable@vger.kernel.org

Software have to abort command ring and cancel command
when a command is failed or hang. Otherwise, the command
ring will hang up and can't handle the others. An example
of a command that may hang is the Address Device Command,
because waiting for a SET_ADDRESS request to be acknowledged
by a USB device is outside of the xHC's ability to control.

To cancel a command, software will initialize a command
descriptor for the cancel command, and add it into a
cancel_cmd_list of xhci.

Sarah: Fixed missing newline on "Have the command ring been stopped?"
debugging statement.

This patch should be backported to kernels as old as 3.0, that contain
the commit 7ed603ec "xhci: Add an
assertion to check for virt_dev=0 bug." That commit papers over a NULL
pointer dereference, and this patch fixes the underlying issue that
caused the NULL pointer dereference.
Signed-off-by: NElric Fu <elricfu1@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: NMiroslav Sabljic <miroslav.sabljic@avl.com>
Cc: stable@vger.kernel.org

Adding cmd_ring_state for command ring. It helps to verify
the current command ring state for controlling the command
ring operations.

This patch should be backported to kernels as old as 3.0.  The commit
7ed603ec "xhci: Add an assertion to
check for virt_dev=0 bug." papers over the NULL pointer dereference that
I now believe is related to a timed out Set Address command.  This (and
the four patches that follow it) contain the real fix that also allows
VIA USB 3.0 hubs to consistently re-enumerate during the plug/unplug
stress tests.
Signed-off-by: NElric Fu <elricfu1@gmail.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: NMiroslav Sabljic <miroslav.sabljic@avl.com>
Cc: stable@vger.kernel.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

The Intel desktop boards DH77EB and DH77DF have a hardware issue that
can be worked around by BIOS.  If the USB ports are switched to xHCI on
shutdown, the xHCI host will send a spurious interrupt, which will wake
the system.  Some BIOS will work around this, but not all.

The bug can be avoided if the USB ports are switched back to EHCI on
shutdown.  The Intel Windows driver switches the ports back to EHCI, so
change the Linux xHCI driver to do the same.

Unfortunately, we can't tell the two effected boards apart from other
working motherboards, because the vendors will change the DMI strings
for the DH77EB and DH77DF boards to their own custom names.  One example
is Compulab's mini-desktop, the Intense-PC.  Instead, key off the
Panther Point xHCI host PCI vendor and device ID, and switch the ports
over for all PPT xHCI hosts.

The only impact this will have on non-effected boards is to add a couple
hundred milliseconds delay on boot when the BIOS has to switch the ports
over from EHCI to xHCI.

This patch should be backported to kernels as old as 3.0, that contain
the commit 69e848c2 "Intel xhci: Support
EHCI/xHCI port switching."
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: NDenis Turischev <denis@compulab.co.il>
Tested-by: NDenis Turischev <denis@compulab.co.il>
Cc: stable@vger.kernel.org

When we encounter an xHCI host that needs the XHCI_TRUST_TX_LENGTH
quirk, the xHCI driver ends up spewing messages about the quirk into
dmesg every time a short packet occurs.  Change the xHCI driver to
rate-limit such warnings.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: NMatthew Hall <mhall@mhcomputing.net>
Reported-by: NGary E. Miller <gem@rellim.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

All Intel xHCI host controllers support USB 3.0 Link Power Management.

The Panther Point xHCI host controller needs the xHCI driver to
calculate the U1 and U2 timeout values, because it will blindly accept a
MEL that would cause scheduling issues.

The Lynx Point xHCI host controller will reject MEL values that are too
high, but internally it implements the same algorithm that is needed for
Panther Point xHCI.

Simplify the code paths by just having the xHCI driver calculate what
the U1/U2 timeouts should be.  Comments on the policy are in the code.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The choice of U1 and U2 timeouts for USB 3.0 Link Power Management (LPM)
is highly host controller specific.  Here are a few examples of why it's
host specific:

 1. Setting the U1/U2 timeout too short may cause the link to go into
    U1/U2 in between service intervals, which some hosts may tolerate,
    and some may not.

 2. The host controller has to modify its bus schedule in order to take
    into account the Maximum Exit Latency (MEL) to bring all the links
    from the host to the device into U0.  If the MEL is too big, and it
    takes too long to bring the links into an active state, the host
    controller may not be able to service periodic endpoints in time.

 3. Host controllers may also have scheduling limitations that force
    them to disable U1 or U2 if a USB device is behind too many tiers of
    hubs.

We could take an educated guess at what U1/U2 timeouts may work for a
particular host controller.  However, that would result in a binary
search on every new configuration or alt setting installation, with
multiple failed Evaluate Context commands.  Worse, the host may blindly
accept the timeouts and just fail to update its schedule for U1/U2 exit
latencies, which could result in randomly delayed periodic transfers.

Since we don't want to cause jitter in periodic transfers, or delay
config/alt setting changes too much, lay down a framework that xHCI
vendors can extend in order to add their own U1/U2 timeout policies.

To extend the framework, they will need to:

 - Modify the PCI init code to add a new xhci->quirk for their host, and
   set the XHCI_LPM_SUPPORT quirk flag.
 - Add their own vendor-specific hooks, like the ones that will be added
   in xhci_call_host_update_timeout_for_endpoint() and
   xhci_check_tier_policy()
 - Make the LPM enable/disable methods call those functions based on the
   xhci->quirk for their host.

An example will be provided for the Intel xHCI host controller in the
next patch.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

We want to do everything we can to ensure that USB 3.0 Link Power
Management (LPM) can be disabled when it is enabled.  If LPM can't be
disabled, we can't suspend USB 3.0 devices, or reset them.  To make sure
we can submit the command to disable LPM, allocate a command in the
xhci_hcd structure, and reserve one TRB on the command ring.

We only need one command per xHCI driver instance, because LPM is only
disabled or enabled while the USB core is holding the bandwidth_mutex
that is shared between the xHCI USB 2.0 and USB 3.0 roothubs.  The
bandwidth_mutex will be held until the command completes, or times out.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

The upcoming USB 3.0 Link PM patches will introduce new API to enable
and disable low-power link states.  We must be able to disable LPM in
order to reset a device, or place the device into U3 (device suspend).
Therefore, we need to make sure the Evaluate Context command to disable
the LPM timeouts can't fail due to there being no room on the command
ring.

Introduce a new flag to the function that queues the Evaluate Context
command, command_must_succeed.  This tells the ring handler that a TRB
has already been reserved for the command (by incrementing
xhci->cmd_ring_reserved_trbs), and basically ensures that prepare_ring()
won't fail.  A similar flag was already implemented for the Configure
Endpoint command queuing function.

All functions that currently call xhci_configure_endpoint() to issue an
Evaluate Context command pass "false" for the "must_succeed" parameter,
so this patch should have no effect on current xHCI driver behavior.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

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>

Sergio reported that when he recorded audio from a USB headset mic
plugged into the USB 3.0 port on his ASUS N53SV-DH72, the audio sounded
"robotic".  When plugged into the USB 2.0 port under EHCI on the same
laptop, the audio sounded fine.  The device is:

Bus 002 Device 004: ID 046d:0a0c Logitech, Inc. Clear Chat Comfort USB Headset

The problem was tracked down to the Fresco Logic xHCI host controller
not correctly reporting short transfers on isochronous IN endpoints.
The driver would submit a 96 byte transfer, the device would only send
88 or 90 bytes, and the xHCI host would report the transfer had a
"successful" completion code, with an untransferred buffer length of 8
or 6 bytes.

The successful completion code and non-zero untransferred length is a
contradiction.  The xHCI host is supposed to only mark a transfer as
successful if all the bytes are transferred.  Otherwise, the transfer
should be marked with a short packet completion code.  Without the EHCI
bus trace, we wouldn't know whether the xHCI driver should trust the
completion code or the untransferred length.  With it, we know to trust
the untransferred length.

Add a new xHCI quirk for the Fresco Logic host controller.  If a
transfer is reported as successful, but the untransferred length is
non-zero, print a warning.  For the Fresco Logic host, change the
completion code to COMP_SHORT_TX and process the transfer like a short
transfer.

This should be backported to stable kernels that contain the commit
f5182b41 "xhci: Disable MSI for some
Fresco Logic hosts."  That commit was marked for stable kernels as old
as 2.6.36.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: NSergio Correia <lists@uece.net>
Tested-by: NSergio Correia <lists@uece.net>
Cc: stable@vger.kernel.org
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

While we're at that, define IMAN bitfield to aid readability.

The interrupt enable bit should be set once on driver init, and we
shouldn't need to continually re-enable it.  Commit c21599a3 introduced
a read of the irq_pending register, and that allows us to preserve the
state of the IE bit.  Before that commit, we were blindly writing 0x3 to
the register.

This patch should be backported to kernels as old as 2.6.36, or ones
that contain the commit c21599a3 "USB:
xhci: Reduce reads and writes of interrupter registers".
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

This adds a fairly simple xhci-platform driver support. Currently it is
used by the dwc3 driver for supporting host mode.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

If room_on_ring() check fails, try to expand the ring and check again.

When expand a ring, use a cached ring or allocate new segments, link
the original ring and the new ring or segments, update the original ring's
segment numbers and the last segment pointer.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: NPaul Zimmerman <Paul.Zimmerman@synopsys.com>

In the past, the room_on_ring() check was implemented by walking all over
the ring, which is wasteful and complicated.

Count the number of free TRBs instead. The free TRBs number should be
updated when enqueue/dequeue pointer is updated, or upon the completion
of a set dequeue pointer command.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: NPaul Zimmerman <Paul.Zimmerman@synopsys.com>

Store the ring's last segment pointer and number of segments for ring
expansion usage.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: NPaul Zimmerman <Paul.Zimmerman@synopsys.com>

When allocate a ring, store its type - four transfer types for endpoint,
TYPE_STREAM for stream transfer, and TYPE_COMMAND/TYPE_EVENT for xHCI host.

This helps to get rid of three bool function parameters: link_trbs, isoc
and consumer.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: NPaul Zimmerman <Paul.Zimmerman@synopsys.com>

__ffs() can tell us which is the SEGMENT_SHIFT value
to be used. This will prevent problems when users are
too fast and don't pay attention to the need of fixing
the Shift after changing TRBS_PER_SEGMENT.
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

USB 3.0 hubs don't have a port suspend change bit (that bit is now
reserved).  Instead, when a host-initiated resume finishes, the hub sets
the port link state change bit.

When a USB 3.0 device initiates remote wakeup, the parent hubs with
their upstream links in U3 will pass the LFPS up the chain.  The first
hub that has an upstream link in U0 (which may be the roothub) will
reflect that LFPS back down the path to the device.

However, the parent hubs in the resumed path will not set their link
state change bit.  Instead, the device that initiated the resume has to
send an asynchronous "Function Wake" Device Notification up to the host
controller.  Therefore, we need a way to notify the USB core of a device
resume without going through the normal hub URB completion method.

First, make the xHCI roothub act like an external USB 3.0 hub and not
pass up the port link state change bit when a device-initiated resume
finishes.  Introduce a new xHCI bit field, port_remote_wakeup, so that
we can tell the difference between a port coming out of the U3Exit state
(host-initiated resume) and the RExit state (ending state of
device-initiated resume).

Since the USB core can't tell whether a port on a hub has resumed by
looking at the Hub Status buffer, we need to introduce a bitfield,
wakeup_bits, that indicates which ports have resumed.  When the xHCI
driver notices a port finishing a device-initiated resume, we call into
a new USB core function, usb_wakeup_notification(), that will set
the right bit in wakeup_bits, and kick khubd for that hub.

We also call usb_wakeup_notification() when the Function Wake Device
Notification is received by the xHCI driver.  This covers the case where
the link between the roothub and the first-tier hub is in U0, and the
hub reflects the resume signaling back to the device without giving any
indication it has done so until the device sends the Function Wake
notification.

Change the code in khubd that handles the remote wakeup to look at the
state the USB core thinks the device is in, and handle the remote wakeup
if the port's wakeup bit is set.

This patch only takes care of the case where the device is attached
directly to the roothub, or the USB 3.0 hub that is attached to the root
hub is the device sending the Function Wake Device Notification (e.g.
because a new USB device was attached).  The other cases will be covered
in a second patch.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

I encountered a result of COMP_2ND_BW_ERR while improving how the pwc
webcam driver handles not having the full usb1 bandwidth available to
itself.

I created the following test setup, a NEC xhci controller with a
single TT USB 2 hub plugged into it, with a usb keyboard and a pwc webcam
plugged into the usb2 hub. This caused the following to show up in dmesg
when trying to stream from the pwc camera at its highest alt setting:

xhci_hcd 0000:01:00.0: ERROR: unexpected command completion code 0x23.
usb 6-2.1: Not enough bandwidth for altsetting 9

And usb_set_interface returned -EINVAL, which caused my pwc code to not
do the right thing as it expected -ENOSPC.

This patch makes the xhci driver properly handle COMP_2ND_BW_ERR and makes
usb_set_interface return -ENOSPC as expected.

This should be backported to stable kernels as old as 2.6.32.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

The xHCI driver will create an xhci_hcd structure, not an ehci_hci
structure.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This removes the need of ifdefs within the init function and with it the
headache about the correct clean without bus X but with bus/platform Y &
Z.
xhci-pci is only compiled if CONFIG_PCI is selected which can be
de-selected now without trouble. For now the result is kinda useless
because we have no other glue code. However, since nobody is using
USB_ARCH_HAS_XHCI then it should not be an issue :)
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

xhci_gen_setup() is generic so it can be used to perform the bare xhci
setup even on non-pci based platform. The typedef for the function
pointer is moved into the headerfile
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Setting the chain (CH) bit in the link TRB of isochronous transfer rings
is required by AMD 0.96 xHCI host controller to successfully transverse
multi-TRB TD that span through different memory segments.

When a Missed Service Error event occurs, if the chain bit is not set in
the link TRB and the host skips TDs which just across a link TRB, the
host may falsely recognize the link TRB as a normal TRB. You can see
this may cause big trouble - the host does not jump to the right address
which is pointed by the link TRB, but continue fetching the memory which
is after the link TRB address, which may not even belong to the host,
and the result cannot be predicted.

This causes some big problems. Without the former patch I sent: "xHCI:
prevent infinite loop when processing MSE event", the system may hang.
With that patch applied, system does not hang, but the host still access
wrong memory address and isoc transfer will fail. With this patch,
isochronous transfer works as expected.

This patch should be applied to kernels as old as 2.6.36, which was when
the first isochronous support was added for the xHCI host controller.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
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>

This patch tests USB2 software LPM for a USB2 LPM-capable device.

When a lpm-capable device is addressed, if the host also supports software
LPM, apply a test by putting the device into L1 state and resume it to see
if the device can do L1 suspend/resume successfully.

If the device fails to enter L1 or resume from L1 state, it may not
function normally and usbcore may disconnect and re-enumerate it. In this
case, store the device's Vid and Pid information, make sure the host will
not test LPM for it twice.

The test result is per device/host. Some devices claim to be lpm-capable,
but fail to enter L1 or resume. So the test is necessary.

The xHCI 1.0 errata has modified the USB2.0 LPM implementation. It redefines
the HIRD field to BESL, and adds another register Port Hardware LPM Control
(PORTHLPMC). However, this should not affect the LPM behavior on xHC which
does not implement 1.0 errata.

USB2.0 LPM errata defines a new bit BESL in the device's USB 2.0 extension
descriptor. If the device reports it uses BESL, driver should use BESL
instead of HIRD for it.
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>

Check the host's USB2 LPM capability.

USB2 software LPM support is optional for xHCI 0.96 hosts. xHCI 1.0 hosts
should support software LPM, and may support hardware LPM.
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>

The Intel Panther Point xHCI host tracks SuperSpeed endpoints in a
different way than USB 2.0/1.1 endpoints.  The bandwidth interval tables
are not used, and instead the bandwidth is calculated in a very simple
way.  Bandwidth for SuperSpeed endpoints is tracked individually in each
direction, since each direction has the full USB 3.0 bandwidth available.
10% of the bus bandwidth is reserved for non-periodic transfers.

This checking would be more complex if we had USB 3.0 LPM enabled, because
an additional latency for isochronous ping times need to be taken into
account.  However, we don't have USB 3.0 LPM support in Linux yet.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The "Mult" bits in the SuperSpeed Endpoint Companion Descriptor are
zero-based, and the xHCI host controller wants them to be zero-based in
the input context.  However, for the bandwidth math, we want them to be
one-based.  Fix this.

Fix the documentation about the endpoint bandwidth mult variable in the
xhci.h file, which says it is zero-based.  Also fix the documentation
about num_packets, which is also one-based, not zero-based.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

instead of reading the xhci interface version each time _even_ if the
quirk is not required, simply check if the quirk flag is set. This flag
is only set of the module parameter is set and here is where I moved the
version check to.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Now that we have a bandwidth interval table per root port or TT that
describes the endpoint bandwidth information, we can finally use it to
check whether the bus bandwidth is oversubscribed for a new device
configuration/alternate interface setting.

The complication for this algorithm is that the bit of hardware logic that
creates the bus schedule is only 12-bit logic.  In order to make sure it
can represent the maximum bus bandwidth in 12 bits, it has to convert the
endpoint max packet size and max esit payload into "blocks" (basically a
less-precise representation).  The block size for each speed of device is
different, aside from low speed and full speed.  In order to make sure we
don't allow a setup where the scheduler might fail, we also have to do the
bandwidth checking in blocks.

After checking that the endpoints fit in the schedule, we store the
bandwidth used for this root port or TT.  If this is a FS/LS device under
an external HS hub, we also update the TT bandwidth and the root port
bandwidth (if this is a newly activated or deactivated TT).

I won't go into the details of the algorithm, as it's pretty well
documented in the comments.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

In order to update the root port or TT's bandwidth interval table, we will
need to keep track of a list of endpoints, per interval.  That way we can
easily know the new largest max packet size when we have to remove an
endpoint.

Add an endpoint list for each root port or TT structure, sorted by
endpoint max packet size.  Insert new endpoints into the list such that
the head of the list always has the endpoint with the greatest max packet
size.  Only insert endpoints and update the interval table with new
information when those endpoints are periodic.

Make sure to update the number of active TTs when we add or drop periodic
endpoints.  A TT is only considered active if it has one or more periodic
endpoints attached (control and bulk are best effort, and counted in the
20% reserved on the high speed bus).  If the number of active endpoints
for a TT was zero, and it's now non-zero, increment the number of active
TTs for the rootport.  If the number of active endpoints was non-zero, and
it's now zero, decrement the number of active TTs.

We have to be careful when we're checking the bandwidth for a new
configuration/alt setting.  If we don't have enough bandwidth, we need to
be able to "roll back" the bandwidth information stored in the endpoint
and the root port/TT interval bandwidth table.  We can't just create a
copy of the interval bandwidth table, modify it, and check the bandwidth
with the copy because we have lists of endpoints and entries can't be on
more than one list.  Instead, we copy the old endpoint bandwidth
information, and use it to revert the interval table when the bandwidth
check fails.

We don't check the bandwidth after endpoints are dropped from the interval
table when a device is reset or freed after a disconnect, because having
endpoints use less bandwidth should not push the bandwidth usage over the
limits.  Besides which, we can't fail a device disconnect.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

In the upcoming patches, we'll use some stored endpoint information to
make software keep track of the worst-case bandwidth schedule.  We need to
store several variables associated with each periodic endpoint:
 - the type of endpoint
 - Max Packet Size
 - Mult
 - Max ESIT payload
 - Max Burst Size (aka number of packets, stored in one-based form)
 - the endpoint interval (normalized to powers of 2 microframes)

All this information is available to the hardware, and stored in its
device output context.  However, we need to ensure that the new
information is stored before the xHCI driver drops the xhci->lock to wait
on the Configure Endpoint command, so that another driver requesting a
configuration or alt setting change will see the update.  The Configure
Endpoint command will never fail on the hardware that needs this software
bandwidth checking (assuming the slot is enabled and the flags are set
properly), so updating the endpoint info before the command completes
should be fine.

Until we add in the bandwidth checking code, just update the endpoint
information after the Configure Endpoint command completes, and after a
Reset Device command completes.  Don't bother to clear the endpoint
bandwidth info when a device is being freed, since the xhci_virt_ep is
just going to be freed anyway.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>