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The hub status endpoint has a long 'bInterval', which is 255ms
for FS/LS device and 256ms for HS device according to USB 2.0 spec,
so the device connection change may be reported later more than 255ms
via status pipe.
The connection change in hub may have been happened already on the
downstream ports, but no status URB completes when it is killed
in hub_suspend(auto), so the connection change may be missed by some
buggy hub devices, which won't generate remote wakeup signal after
their remote wakeup is enabled and they are put into suspend state.
The problem can be observed at least on the below Genesys Logic, Inc.
hub devices:
0x05e3,0x0606
0x05e3,0x0608
In theory, there is no way to fix the problem completely, but we
can make it less likely to occur by this patch.
This patch introduces one quirk of HUB_QUIRK_CHECK_PORTS_AUTOSUSPEND
to check ports' change during hub_suspend(auto) for the buggy
devices. If ports' change is found, terminate the auto suspend and
return to working state.
So for the buggy hubs, if the connection change happend before
the ports' check, it can be handled correctly. If it happens between
the ports' check and enabling remote wakeup/entering suspend, it
will be missed. Considered the interval is quite short, it is very
less likely to happen during the window.
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch (as1620) speeds up USB root-hub resumes in the common case
where every enabled port has its suspend feature set (which currently
will be true for every runtime resume of the root hub). If all the
enabled ports are suspended then resuming the root hub won't resume
any of the downstream devices. In this case there's no need for a
Resume Recovery delay, because that delay is meant to give devices a
chance to get ready for active use.
To keep track of the port suspend features, the patch adds a
"port_is_suspended" flag to struct usb_device. This has to be tracked
separately from the device's state; it's entirely possible for a USB-2
device to be suspended while the suspend feature on its parent port is
clear. The reason is that devices will go into suspend whenever their
parent hub does.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reviewed-by: Peter Chen <peter.chen@freescale.com>
Tested-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch (as1619) improves the interface to the "hub_for_each_child"
macro. The name clearly suggests that the macro iterates over child
devices; it does not suggest that the loop will also iterate over
unnconnected ports.
The patch changes the macro so that it will skip over unconnected
ports and iterate only the actual child devices. The two existing
call sites are updated to avoid testing for a NULL child pointer,
which is now unnecessary.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
flush_work_sync and flush_work are now the same and flush_work_sync
has been deprecated. This fixes the following warning:
drivers/usb/core/hub.c: In function hub_quiesce:
drivers/usb/core/hub.c:1216:3: warning: flush_work_sync is deprecated (declared at include/linux/workqueue.h:448) [-Wdeprecated-declarations]
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch (as1611) updates the USB documentation and kerneldoc to
give a more precise meaning for the URB_ISO_ASAP flag and to explain
more of the details of scheduling for isochronous URBs.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB 3.0 Link PM fixes.
Hi Greg,
Here's four fixes for the USB 3.0 Link Power Management code. They
work around some USB 3.0 devices that don't support LPM, like the
Western Digital My Passport hard drive. They also fix an LPM disable
ref count bug that would cause LPM to remain disabled for a device
after a failed probe.
Please queue for 3.7 after the merge window closes. Several patches are
marked for stable.
Sarah Sharp
SEL and PEL are in microseconds, not milliseconds. Also, fix a split
string that will trigger checkpatch warnings.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
The Set SEL control transfer tells a device the exit latencies
associated with a device-initated U1 or U2 exit. Since a parent hub may
initiate a transition to U1 soon after a downstream port's U1 timeout is
set, we need to make sure the device receives the Set SEL transfer
before the parent hub timeout is set.
This patch should be backported to kernels as old as 3.5, that contain
the commit 1ea7e0e8e3 "USB: Add support to
enable/disable USB3 link states."
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org
Some USB 3.0 devices signal that they don't implement Link PM by having
all zeroes in the U1/U2 exit latencies in their SuperSpeed BOS
descriptor. Don found that a Western Digital device he has experiences
transfer errors when LPM is enabled. The lsusb shows the U1/U2 exit
latencies are set to zero:
Binary Object Store Descriptor:
bLength 5
bDescriptorType 15
wTotalLength 22
bNumDeviceCaps 2
SuperSpeed USB Device Capability:
bLength 10
bDescriptorType 16
bDevCapabilityType 3
bmAttributes 0x00
Latency Tolerance Messages (LTM) Supported
wSpeedsSupported 0x000e
Device can operate at Full Speed (12Mbps)
Device can operate at High Speed (480Mbps)
Device can operate at SuperSpeed (5Gbps)
bFunctionalitySupport 1
Lowest fully-functional device speed is Full Speed (12Mbps)
bU1DevExitLat 0 micro seconds
bU2DevExitLat 0 micro seconds
The fix is to not enable LPM for a particular link state if we find its
corresponding exit latency is zero.
This patch should be backported to kernels as old as 3.5, that contain
the commit 1ea7e0e8e3 "USB: Add support to
enable/disable USB3 link states."
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: Don Zickus <dzickus@redhat.com>
Tested-by: Don Zickus <dzickus@redhat.com>
Cc: stable@vger.kernel.org
Before a driver is probed, we want to disable USB 3.0 Link Power
Management (LPM), in case the driver needs hub-initiated LPM disabled.
After the probe finishes, we want to attempt to re-enable LPM, order to
balance the LPM ref count.
When a probe fails (such as when libusual doesn't want to bind to a USB
3.0 mass storage device), make sure to balance the LPM ref counts by
re-enabling LPM.
This patch should be backported to kernels as old as 3.5, that contain
the commit 8306095fd2 "USB: Disable USB
3.0 LPM in critical sections."
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org
Pul ACPI & Power Management updates from Len Brown:
- acpidump utility added
- intel_idle driver now supports IVB Xeon
- turbostat utility can now count SMIs
- ACPI can now bind to USB3 hubs
- misc fixes
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux: (49 commits)
ACPI: Add new sysfs interface to export device description
ACPI: Harden acpi_table_parse_entries() against BIOS bug
tools/power/turbostat: add option to count SMIs, re-name some options
tools/power turbostat: add [-d MSR#][-D MSR#] options to print counter deltas
intel_idle: enable IVB Xeon support
tools/power turbostat: add [-m MSR#] option
tools/power turbostat: make -M output pretty
tools/power turbostat: print more turbo-limit information
tools/power turbostat: delete unused line
tools/power turbostat: run on IVB Xeon
tools/power/acpi/acpidump: create acpidump(8), local make install targets
tools/power/acpi/acpidump: version 20101221 - find dynamic tables in sysfs
ACPI: run _OSC after ACPI_FULL_INITIALIZATION
tools/power/acpi/acpidump: create acpidump(8), local make install targets
tools/power/acpi/acpidump: version 20101221 - find dynamic tables in sysfs
tools/power/acpi/acpidump: version 20071116
tools/power/acpi/acpidump: version 20070714
tools/power/acpi/acpidump: version 20060606
tools/power/acpi/acpidump: version 20051111
xo15-ebook: convert to module_acpi_driver()
...
This patch (as1607) fixes a race that can occur if a USB host
controller is removed while a process is reading the
/sys/kernel/debug/usb/devices file.
The usb_device_read() routine uses the bus->root_hub pointer to
determine whether or not the root hub is registered. The is not a
valid test, because the pointer is set before the root hub gets
registered and remains set even after the root hub is unregistered and
deallocated. As a result, usb_device_read() or usb_device_dump() can
access freed memory, causing an oops.
The patch changes the test to use the hcd->rh_registered flag, which
does get set and cleared at the appropriate times. It also makes sure
to hold the usb_bus_list_lock mutex while setting the flag, so that
usb_device_read() will become aware of new root hubs as soon as they
are registered.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Don Zickus <dzickus@redhat.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch (as1607) fixes a race that can occur if a USB host
controller is removed while a process is reading the
/sys/kernel/debug/usb/devices file.
The usb_device_read() routine uses the bus->root_hub pointer to
determine whether or not the root hub is registered. The is not a
valid test, because the pointer is set before the root hub gets
registered and remains set even after the root hub is unregistered and
deallocated. As a result, usb_device_read() or usb_device_dump() can
access freed memory, causing an oops.
The patch changes the test to use the hcd->rh_registered flag, which
does get set and cleared at the appropriate times. It also makes sure
to hold the usb_bus_list_lock mutex while setting the flag, so that
usb_device_read() will become aware of new root hubs as soon as they
are registered.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Don Zickus <dzickus@redhat.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
retval is 0, and carefully assigned - and tested as non zero.
This is not useful. While we are at it remove some other bogus initialisation
in the function
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This resolves the merge problems with:
drivers/usb/dwc3/gadget.c
drivers/usb/musb/tusb6010.c
that had been seen in linux-next.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit ff823c79a5 ("usb: move children
to struct usb_port") forgot to consider the hub_disconnect sequence,
which releases ports before quiescing the hub, which will lead to a
use-after-free, since hub_quiesce() will try to disconnect ports'
children, which are already deallocated. Simple modprobe dummy_hcd &&
rmmod dummy_hcd will illustrate the problem.
This patch moves deallocation of hub's ports after hub_quiesce() call
in hub_disconnect().
Cc: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Because the IRQF_DISABLED as the flag is now a NOOP and has been
deprecated and in hardirq context the interrupt is disabled.
so in usb/host code:
Removing the usage of flag IRQF_DISABLED;
Removing the calling local_irq save/restore actions in irq
handler usb_hcd_irq();
Signed-off-by: liu chuansheng <chuansheng.liu@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds two sysfs files for each usb hub port to allow userspace
to control the port power policy.
For an upcoming Intel xHCI roothub, this will translate into ACPI calls
to completely power off or power on the port. As a reminder, when these
ports are completely powered off, the USB host and device will see a
physical disconnect. All future USB device connections will be lost,
and the device will not be able to signal a remote wakeup.
The control sysfs file can be written to with two options:
"on" - port power must be on.
"off" - port must be off.
The state sysfs file reports usb port's power state:
"on" - powered on
"off" - powered off
"error" - can't get power state
For now, let userspace dictate the port power off policy. Future
patches may add an in-kernel policy.
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Alan Stern pointed out that a USB port could potentially get powered off
when the attached USB device is in the middle of enumerating, due to
race conditions:
http://marc.info/?l=linux-usb&m=134130616707548&w=2
If that happens, we need to ensure the enumeration fails. If a call to
usb_get_descriptor() fails for a reason other than a Stall, return an
error. That should handle the case where the port is powered off.
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the upcoming USB port power off patches, we need to know whether a
USB port can ever see a disconnect event. Often USB ports are internal
to a system, and users can't disconnect USB devices from that port.
Sometimes those ports will remain empty, because the OEM chose not to
connect an internal USB device to that port.
According to ACPI Spec 9.13, PLD indicates whether USB port is
user visible and _UPC indicates whether a USB device can be connected to
the USB port (we'll call this "connectible"). Here's a matrix of the
possible combinations:
Visible Connectible
Name Example
-------------------------------------------------------------------------
Yes No Unknown (Invalid state.)
Yes Yes Hot-plug USB ports on the outside of a laptop.
A user could freely connect and disconnect
USB devices.
No Yes Hard-wired A USB modem hard-wired to a port on the
inside of a laptop.
No No Not used The port is internal to the system and
will remain empty.
Represent each of these four states with an enum usb_port_connect_type.
The four states are USB_PORT_CONNECT_TYPE_UNKNOWN,
USB_PORT_CONNECT_TYPE_HOT_PLUG, USB_PORT_CONNECT_TYPE_HARD_WIRED, and
USB_PORT_NOT_USED. When we get the USB port's acpi_handle, store the
state in connect_type in struct usb_port.
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the ACPI DSDT table, only usb root hub and usb ports are ACPI device
nodes. Originally, we bound the usb port's ACPI node to the usb device
attached to the port. However, we want to access those ACPI port
methods when the port is empty, and there's no usb_device associated
with that port.
Now that the usb port is a real device, we can bind the port's ACPI node
to struct usb_port instead.
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The usb_device structure contains an array of usb_device "children".
This array is only valid if the usb_device is a hub, so it makes no
sense to store it there. Instead, store the usb_device child
in its parent usb_port structure.
Since usb_port is an internal USB core structure, add a new function to
get the USB device child, usb_hub_find_child(). Add a new macro,
usb_hub_get_each_child(), to iterate over all the children attached to a
particular USB hub.
Remove the printing the USB children array pointer from the usb-ip
driver, since it's really not necessary.
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch turns each USB port on a hub into a new struct device. This
new device has the USB hub interface device as its parent. The port
devices are stored in a new structure (usb_port), and an array of
usb_ports are dynamically allocated once we know how many ports the USB
hub has.
Move the port_owner variable out of usb_hub and into this new structure.
A new file will be created in the hub interface sysfs directory, so
add documentation.
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The kernel's version number is used as decimal in the bcdDevice field of
the RH descriptor. For kernel version v3.12 we would see 3.0c in lsusb.
I am not sure how important it is to stick with bcd values since this is
this way since we started git history and nobody complained (however back
then we reported only 2.6).
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Apps which deal with devices which also have a kernel driver, need to do
the following:
1) Check which driver is attached, so as to not detach the wrong driver
(ie detaching usbfs while another instance of the app is using the device)
2) Detach the kernel driver
3) Claim the interface
Where moving from one step to the next for both 1-2 and 2-3 consists of
a (small) race window. So currently such apps are racy and people just live
with it.
This patch adds a new ioctl which makes it possible for apps to do this
in a race free manner. For flexibility apps can choose to:
1) Specify the driver to disconnect
2) Specify to disconnect any driver except for the one named by the app
3) Disconnect any driver
Note that if there is no driver attached, the ioctl will just act like the
regular claim-interface ioctl, this is by design, as returning an error for
this condition would open a new bag of race-conditions.
Changes in v2:
-Fix indentation of if blocks where the condition spans multiple lines
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since the attribute avoid_reset_quirk is work for all devices including
those devices that can't morph, convert USB_QUIRK_RESET_MORPHS to
USB_QUIRK_RESET.
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For following the way the rest of the usb core does, this patch is to change
the place of setting release callback.
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In USB, the word "config" already has aseparate meaning. So it will
cause confusion if use "config" as variable's name for other purposes.
This patch is to convert the "config" to "val"
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull random subsystem patches from Ted Ts'o:
"This patch series contains a major revamp of how we collect entropy
from interrupts for /dev/random and /dev/urandom.
The goal is to addresses weaknesses discussed in the paper "Mining
your Ps and Qs: Detection of Widespread Weak Keys in Network Devices",
by Nadia Heninger, Zakir Durumeric, Eric Wustrow, J. Alex Halderman,
which will be published in the Proceedings of the 21st Usenix Security
Symposium, August 2012. (See https://factorable.net for more
information and an extended version of the paper.)"
Fix up trivial conflicts due to nearby changes in
drivers/{mfd/ab3100-core.c, usb/gadget/omap_udc.c}
* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random: (33 commits)
random: mix in architectural randomness in extract_buf()
dmi: Feed DMI table to /dev/random driver
random: Add comment to random_initialize()
random: final removal of IRQF_SAMPLE_RANDOM
um: remove IRQF_SAMPLE_RANDOM which is now a no-op
sparc/ldc: remove IRQF_SAMPLE_RANDOM which is now a no-op
[ARM] pxa: remove IRQF_SAMPLE_RANDOM which is now a no-op
board-palmz71: remove IRQF_SAMPLE_RANDOM which is now a no-op
isp1301_omap: remove IRQF_SAMPLE_RANDOM which is now a no-op
pxa25x_udc: remove IRQF_SAMPLE_RANDOM which is now a no-op
omap_udc: remove IRQF_SAMPLE_RANDOM which is now a no-op
goku_udc: remove IRQF_SAMPLE_RANDOM which was commented out
uartlite: remove IRQF_SAMPLE_RANDOM which is now a no-op
drivers: hv: remove IRQF_SAMPLE_RANDOM which is now a no-op
xen-blkfront: remove IRQF_SAMPLE_RANDOM which is now a no-op
n2_crypto: remove IRQF_SAMPLE_RANDOM which is now a no-op
pda_power: remove IRQF_SAMPLE_RANDOM which is now a no-op
i2c-pmcmsp: remove IRQF_SAMPLE_RANDOM which is now a no-op
input/serio/hp_sdc.c: remove IRQF_SAMPLE_RANDOM which is now a no-op
mfd: remove IRQF_SAMPLE_RANDOM which is now a no-op
...
Most Logitech UVC webcams (both early models that don't advertise UVC
compatibility and newer UVC-advertised devices) require the RESET_RESUME
quirk. Instead of listing each and every model, match the devices based
on the UVC interface information.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a whole class of devices (possibly from a specific vendor, or
across multiple vendors) require a quirk, explictly listing all devices
in the class make the quirks table unnecessarily large. Fix this by
allowing matching devices based on interface information.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: Link PM fixes and Latency Tolerance Messaging
Hi Greg,
Here's four bug fix patches for Link PM (LPM), which are marked for
3.5-stable. There's also three patches that turn on Latency Tolerance
Messaging (LTM) for xHCI host controllers and USB 3.0 devices that support
this low power feature.
Please queue for 3.6.
Sarah Sharp
USB 3.0 devices can optionally support Latency Tolerance Messaging
(LTM). Add a new sysfs file in the device directory to show whether a
device is LTM capable. This file will be present for both USB 2.0 and
USB 3.0 devices.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
USB 3.0 devices may optionally support a new feature called Latency
Tolerance Messaging. If both the xHCI host controller and the device
support LTM, it should be turned on in order to give the system hardware
a better clue about the latency tolerance values of its PCI devices.
Once a Set Feature request to enable LTM is received, the USB 3.0 device
will begin to send LTM updates as its buffers fill or empty, and it can
tolerate more or less latency.
The USB 3.0 spec, section C.4.2 says that LTM should be disabled just
before the device is placed into suspend. Then the device will send an
updated LTM notification, so that the system doesn't think it should
remain in an active state in order to satisfy the latency requirements
of the suspended device.
The Set and Clear Feature LTM enable command can only be sent to a
configured device. The device will respond with an error if that
command is sent while it is in the Default or Addressed state. Make
sure to check udev->actconfig in usb_enable_ltm() and usb_disable_ltm(),
and don't send those commands when the device is unconfigured.
LTM should be enabled once a new configuration is installed in
usb_set_configuration(). If we end up sending duplicate Set Feature LTM
Enable commands on a switch from one installed configuration to another
configuration, that should be harmless.
Make sure that LTM is disabled before the device is unconfigured in
usb_disable_device(). If no drivers are bound to the device, it doesn't
make sense to allow the device to control the latency tolerance of the
xHCI host controller.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
When a user runs `echo 0 > bConfigurationValue` for a USB 3.0 device,
usb_disable_device() is called. This function disables all drivers,
deallocates interfaces, and sets the device configuration value to 0
(unconfigured).
With the new scheme to ensure that unconfigured devices have LPM
disabled, usb_disable_device() must call usb_unlocked_disable_lpm() once
it unconfigures the device.
This commit should be backported to kernels as old as 3.5, that contain
the commit 8306095fd2 "USB: Disable USB
3.0 LPM in critical sections."
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org
