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>
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: Sarah Sharp <sarah.a.sharp@linux.intel.com>
hub_initiated_lpm_disable_count is not used by any code, so remove it.
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
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
The USB 3.0 Set/Clear Feature U1/U2 Enable cannot be sent to a device in
the Default or Addressed state. It can only be sent to a configured
device. Change the USB core to initialize the LPM disable count to 1
(disabled), which reflects this limitation.
Change usb_set_configuration() to ensure that if the device is
unconfigured on entry, usb_lpm_disable() is not called. This avoids
sending the Clear Feature U1/U2 when the device is in the Addressed
state. When usb_set_configuration() exits with a successfully installed
configuration, usb_lpm_enable() will be called.
Once the new configuration is installed, make sure
usb_set_configuration() only calls usb_enable_lpm() if the device moved
to the Configured state. If we have unconfigured the device by sending
it a Set Configuration for config 0, don't enable LPM.
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
The USB 3.0 specification says that sending a Set Feature or Clear
Feature for U1/U2 Enable is not a valid request when the device is in
the Default or Addressed state. It is only valid when the device is in
the Configured state.
The original LPM patch attempted to disable LPM after the device had
been reset by hub_port_init(), before it had the configuration
reinstalled. The TI hub I tested with did not fail the Clear Feature
U1/U2 Enable request that khubd sent while it was in the addressed
state, which is why I didn't catch it.
Move the LPM disable before the device reset, so that we can send the
Clear Feature U1/U2 Enable successfully, and balance the LPM disable
count.
Also delete any calls to usb_enable_lpm() on error paths that lead to
re-enumeration. The calls will fail because the device isn't
configured, and it's not useful to balance the LPM disable count because
the usb_device is about to be destroyed before re-enumeration.
Fix the early exit path ("done" label) to call usb_enable_lpm() to
balance the LPM disable count.
Note that calling usb_reset_and_verify_device() with an unconfigured
device may fail on the first call to usb_disable_lpm(). That's because
the LPM disable count is initialized to 0 (LPM enabled), and
usb_disable_lpm() will attempt to send a Clear Feature U1/U2 request to
a device in the Addressed state. The next patch will fix that.
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
This patch (as1564c) converts the EHCI platform drivers to use the
central ehci_setup() routine for generic controller initialization
rather than each having its own idiosyncratic approach.
The major point of difficulty lies in ehci-pci's many vendor- and
device-specific workarounds. Some of them have to be applied before
calling ehci_setup() and some after, which necessitates a fair amount
of code motion. The other platform drivers require much smaller
changes.
One point not addressed by the patch is whether ports should be
powered on or off following initialization. The different drivers
appear to handle this pretty much at random. In fact it shouldn't
matter, because the hub driver turns on power to all ports when it
binds to the root hub. Straightening that out will be left for
another day.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Sometimes, the driver bindings may know what phy they use.
For example, when using device tree, the usb controller may have a
phandler pointing to usb phy.
Signed-off-by: Richard Zhao <richard.zhao@freescale.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Acked-by: Felipe Balbi <balbi@ti.com>
Tested-by: Subodh Nijsure <snijsure@grid-net.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixed a mistake in the merge conflict resoultion commit(ff9cce) in file
twl6030-usb.c
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch (as1563) removes a lot of duplicated code by moving the
EHCI controller suspend/resume routines into the core driver, where
the various platform drivers can invoke them as needed.
Not only does this simplify these platform drivers, this also makes it
easier for other platform drivers to add suspend/resume support in the
future.
Note: The patch does not touch the ehci-fsl.c file, because its
approach to suspend and resume is so different from all the others.
It will have to be handled specially by its maintainer.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As reported by Dan Carpenter, there is a NULL check in udc_start() that
follows a dereference of the pointer that's being checked. However, at
that point udc pointer shouldn't ever be NULL and if it is, the dereference
should cause an oops.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Richard Zhao <richard.zhao@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Sarah Sharp
Alan Stern
Richard Zhao
Kuninori Morimoto
Kishon Vijay Abraham I
Hans de Goede
Lan Tianyu
Felipe Balbi
Alexander Shishkin