When a USB device is disconnected, usb_unbind_interface is called, which
tries to enable and disable LPM. usb_enable_lpm also try to send a
control command SET SEL to the device.
Since device is already disconnected, therefore it does not make sense
to execute usb_(en/dis)able_lpm.
This patch returns from usb_(en/dis)able_lpm, if device was not in
default state atleast.
Signed-off-by: Pratyush Anand <pratyush.anand@st.com>
Tested-by: Aymen Bouattay <aymen.bouattay@st.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 9262c19d14 "usb: disable port power control if not supported in
wHubCharacteristics" gated enabling runtime pm for usb_port devices on
whether the parent hub supports power control, which causes a
regression. The port must still be allowed to carry out runtime pm
callbacks and receive a -EAGAIN or -EBUSY result. Otherwise the
usb_port device will transition to the pm error state and trigger the
same for the child usb_device.
Prior to the offending commit usb_hub_create_port_device() arranged for
runtime pm to be disabled is dev_pm_qos_expose_flags() failed. Instead,
force the default state of PM_QOS_FLAG_NO_POWER_OFF flag to be set prior
to enabling runtime pm. If that policy can not be set then fail
registration.
Report: http://marc.info/?l=linux-usb&m=140290586301336&w=2
Fixes: 9262c19d14 ("usb: disable port power control if not supported in wHubCharacteristics")
Reported-by: Bjørn Mork <bjorn@mork.no>
Reported-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reading through a recent bug report [1], Alan notes:
"Dan, the warning message in hub_suspend() should mention that the
child device isn't suspended yet."
...update the warning from:
"usb usb3-port4: not suspended yet"
...to:
"usb usb3-port4: device 3-4: not suspended yet"
[1]: http://marc.info/?l=linux-usb&m=140290586301336&w=2
Reported-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit d8521afe35 "usb: assign default peer ports for root hubs"
delayed marking a hub valid (set hdev->maxchild) until it had been fully
configured and to enable the publishing of valid hubs to be serialized
by usb_port_peer_mutex.
However, xhci_update_hub_device() in some cases depends on
hdev->maxchild already being set. Do the minimal fix and move it after
the setting of hdev->maxchild.
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Reported-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Tested-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that 3.15 is released, this merges the 'next' branch into 'master',
bringing us to the normal situation where my 'master' branch is the
merge window.
* accumulated work in next: (6809 commits)
ufs: sb mutex merge + mutex_destroy
powerpc: update comments for generic idle conversion
cris: update comments for generic idle conversion
idle: remove cpu_idle() forward declarations
nbd: zero from and len fields in NBD_CMD_DISCONNECT.
mm: convert some level-less printks to pr_*
MAINTAINERS: adi-buildroot-devel is moderated
MAINTAINERS: add linux-api for review of API/ABI changes
mm/kmemleak-test.c: use pr_fmt for logging
fs/dlm/debug_fs.c: replace seq_printf by seq_puts
fs/dlm/lockspace.c: convert simple_str to kstr
fs/dlm/config.c: convert simple_str to kstr
mm: mark remap_file_pages() syscall as deprecated
mm: memcontrol: remove unnecessary memcg argument from soft limit functions
mm: memcontrol: clean up memcg zoneinfo lookup
mm/memblock.c: call kmemleak directly from memblock_(alloc|free)
mm/mempool.c: update the kmemleak stack trace for mempool allocations
lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations
mm: introduce kmemleak_update_trace()
mm/kmemleak.c: use %u to print ->checksum
...
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Unconditionally wake up the child device when the power session is
recovered.
This addresses the following scenarios:
1/ The device may need a reset on power-session loss, without this
change port power-on recovery exposes khubd to scenarios that
usb_port_resume() is set to handle. Prior to port power control the
only time a power session would be lost is during dpm_suspend of the
hub. In that scenario usb_port_resume() is guaranteed to be called
prior to khubd running for that port. With this change we wakeup the
child device as soon as possible (prior to khubd running again for this
port).
Although khubd has facilities to wake a child device it will only do
so if the portstatus / portchange indicates a suspend state. In the
case of port power control we are not coming from a hub-port-suspend
state. This implementation simply uses pm_request_resume() to wake the
device and relies on the port_dev->status_lock to prevent any collisions
between khubd and usb_port_resume().
2/ This mechanism rate limits port power toggling. The minimum port
power on/off period is now gated by the child device suspend/resume
latency. Empirically this mitigates devices downgrading their connection
on perceived instability of the host connection. This ratelimiting is
really only relevant to port power control testing, but it is a nice
side effect of closing the above race. Namely, the race of khubd for
the given port running while a usb_port_resume() event is pending.
3/ Going forward we are finding that power-session recovery requires
warm-resets (http://marc.info/?t=138659232900003&r=1&w=2). This
mechanism allows for warm-resets to be requested at the same point in
the resume path for hub dpm_suspend power session losses, or port
rpm_suspend power session losses.
4/ If the device *was* disconnected the only time we'll know for sure is
after a failed resume, so it's necessary for usb_port_runtime_resume()
to expedite a usb_port_resume() to clean up the removed device. The
reasoning for this is "least surprise" for the user. Turning on a port
means that hotplug detection is again enabled for the port, it is
surprising that devices that were removed while the port was off are not
disconnected until they are attempted to be used. As a user "why would
I try to use a device I removed from the system?"
1, 2, and 4 are not a problem in the system dpm_resume() case because,
although the power-session is lost, khubd is frozen until after device
resume. For the rpm_resume() case pm_request_resume() is used to
request re-validation of the device, and if it happens to collide with a
khubd run we rely on the port_dev->status_lock to synchronize those
operations.
Besides testing, the primary scenario where this mechanism is expected
to be triggered is when the user changes the port power policy
(control/pm_qos_no_poweroff, or power/control). Each time power is
enabled want to revalidate the child device, where the revalidation is
handled by usb_port_resume().
Given that this arranges for port_dev->child to be de-referenced in
usb_port_runtime_resume() we need to make sure not to collide with
usb_disconnect() that frees the usb_device. To this end we hold the
port active with the "child_usage" reference across the disconnect
event. Subsequently, the need to access hub->child_usage_bits lead to
the creation of hub_disconnect_children() to remove any ambiguity of
which "hub" is being acted on in usb_disconnect() (prompted-by sharp
eyes from Alan).
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Per Alan:
"You mean from within hub_handle_remote_wakeup()? That routine will
never get called if CONFIG_PM_RUNTIME isn't enabled, because khubd
never sees wakeup requests if they arise during system suspend.
In fact, that routine ought to go inside the "#ifdef CONFIG_PM_RUNTIME"
portion of hub.c, along with the other suspend/resume code."
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In general we do not want khubd to act on port status changes that are
the result of in progress resets or USB runtime PM operations.
Specifically port power control testing has been able to trigger an
unintended disconnect in hub_port_connect_change(), paraphrasing:
if ((portstatus & USB_PORT_STAT_CONNECTION) && udev &&
udev->state != USB_STATE_NOTATTACHED) {
if (portstatus & USB_PORT_STAT_ENABLE) {
/* Nothing to do */
} else if (udev->state == USB_STATE_SUSPENDED &&
udev->persist_enabled) {
...
} else {
/* Don't resuscitate */;
}
}
...by falling to the "Don't resuscitate" path or missing
USB_PORT_STAT_CONNECTION because usb_port_resume() was in the middle of
modifying the port status.
So, we want a new lock to hold off khubd for a given port while the
child device is being suspended, resumed, or reset. The lock ordering
rules are now usb_lock_device() => usb_lock_port(). This is mandated by
the device core which may hold the device_lock on the usb_device before
invoking usb_port_{suspend|resume} which in turn take the status_lock on
the usb_port. We attempt to hold the status_lock for the duration of a
port_event() run, and drop/re-acquire it when needing to take the
device_lock. The lock is also dropped/re-acquired during
hub_port_reconnect().
This patch also deletes hub->busy_bits as all use cases are now covered
by port PM runtime synchronization or the port->status_lock and it
pushes down usb_device_lock() into usb_remote_wakeup().
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a port is powered-off, or in the process of being powered-off, prevent
khubd from operating on it. Otherwise, the following sequence of events
leading to an unintended disconnect may occur:
Events:
(0) <set pm_qos_no_poweroff to '0' for port1>
(1) hub 2-2:1.0: hub_resume
(2) hub 2-2:1.0: port 1: status 0301 change 0000
(3) hub 2-2:1.0: state 7 ports 4 chg 0002 evt 0000
(4) hub 2-2:1.0: port 1, power off status 0000, change 0000, 12 Mb/s
(5) usb 2-2.1: USB disconnect, device number 5
Description:
(1) hub is resumed before sending a ClearPortFeature request
(2) hub_activate() notices the port is connected and sets
hub->change_bits for the port
(3) hub_events() starts, but at the same time the port suspends
(4) hub_connect_change() sees the disabled port and triggers disconnect
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In preparation for synchronizing port handling with pm_runtime
transitions refactor port handling into its own subroutine.
We expect that clearing some status flags will be required regardless of
the port state, so handle those first and group all non-trivial actions
at the bottom of the routine.
This also splits off the bottom half of hub_port_connect_change() into
hub_port_reconnect() in prepartion for introducing a port->status_lock.
hub_port_reconnect() will expect the port lock to not be held while
hub_port_connect_change() expects to enter with it held.
Other cleanups include:
1/ reflowing to 80 columns
2/ replacing redundant usages of 'hub->hdev' with 'hdev'
3/ consolidate clearing of ->change_bits() in hub_port_connect_change
4/ consolidate calls to usb_reset_device
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ClearPortFeature(PORT_POWER) on a usb3 port places the port in either a
DSPORT.Powered-off-detect / DSPORT.Powered-off-reset loop, or the
DSPORT.Powered-off state. There is no way to ensure that RX
terminations will persist in this state, so it is possible a device will
degrade to its usb2 connection. Prevent this by blocking power-off of a
usb3 port while its usb2 peer is active, and powering on a usb3 port
before its usb2 peer.
By default the latency between peer power-on events is 0. In order for
the device to not see usb2 active while usb3 is still powering up inject
the hub recommended power_on_good delay. In support of satisfying the
power_on_good delay outside of hub_power_on() refactor the places where
the delay is consumed to call a new hub_power_on_good_delay() helper.
Finally, because this introduces several new checks for whether a port
is_superspeed, cache that disctinction at port creation so that we don't
need to keep looking up the parent hub device.
Acked-by: Alan Stern <stern@rowland.harvard.edu>
[alan]: add a 'superspeed' flag to the port
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We want to manipulate ->did_runtime_put in usb_port_runtime_resume(),
but we don't want that to collide with other updates. Move usb_port
flags to new port-bitmap fields in usb_hub. "did_runtime_put" is renamed
"child_usage_bits" to reflect that it is strictly standing in for the
fact that usb_devices are not the device_model children of their parent
port.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Assume that the peer of a superspeed port is the port with the same id
on the shared_hcd root hub. This identification scheme is required of
external hubs by the USB3 spec [1]. However, for root hubs, tier mismatch
may be in effect [2]. Tier mismatch can only be enumerated via platform
firmware. For now, simply perform the nominal association.
A new lock 'usb_port_peer_mutex' is introduced to synchronize port
device add/remove with peer lookups. It protects peering against
changes to hcd->shared_hcd, hcd->self.root_hub, hdev->maxchild, and
port_dev->child pointers.
[1]: usb 3.1 section 10.3.3
[2]: xhci 1.1 appendix D
Cc: Alan Stern <stern@rowland.harvard.edu>
[alan: usb_port_peer_mutex locking scheme]
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Once usb-acpi has set the port's connect type the usb_device's
->removable attribute can be set in the standard location
set_usb_port_removable().
This also changes behavior in the case where the firmware says that the
port connect type is unknown. In that case just use the default setting
determined from the hub descriptor.
Note, we no longer pass udev->portnum to acpi_find_child_device() in the
root hub case since:
1/ the usb-core sets this to zero
2/ acpi always expects zero
...just pass zero.
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current port name "portX" is ambiguous. Before adding more port
messages rename ports to "<hub-device-name>-portX"
This is an ABI change, but the suspicion is that it will go unnoticed as
the port power control implementation has been broken since its
introduction. If however, someone was relying on the old name we can
add sysfs links from the old name to the new name.
Additionally, it unifies/simplifies port dev_printk messages and modifies
instances of:
dev_XXX(hub->intfdev, ..."port %d"...
dev_XXX(&hdev->dev, ..."port%d"...
into:
dev_XXX(&port_dev->dev, ...
Now that the names are unique usb_port devices it would be nice if they
could be included in /sys/bus/usb. However, it turns out that this
breaks 'lsusb -t'. For now, create a dummy port driver so that print
messages are prefixed "usb 1-1-port3" rather than the
subsystem-ambiguous " 1-1-port3".
Finally, it corrects an odd usage of sscanf("port%d") in usb-acpi.c.
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A hub indicates whether it supports per-port power control via the
wHubCharacteristics field in its descriptor. If it is not supported
a hub will still emulate ClearPortPower(PORT_POWER) requests by
stopping the link state machine. However, since this does not save
power do not bother suspending.
This also consolidates support checks into a
hub_is_port_power_switchable() helper.
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The USB core doesn't properly handle mutual exclusion between
resetting a hub and changing the power states of the hub's ports. We
need to avoid sending port-power requests to the hub while it is being
reset, because such requests cannot succeed.
This patch fixes the problem by keeping track of when a reset is in
progress. At such times, attempts to suspend (power-off) a port will
fail immediately with -EBUSY, and calls to usb_port_runtime_resume()
will update the power_is_on flag and return immediately. When the
reset is complete, hub_activate() will automatically restore each port
to the proper power state.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch creates a separate instance of the usb_address0 mutex for each USB
bus, and attaches it to the usb_bus device struct. This allows devices on
separate buses to be enumerated in parallel; saving time.
In the current code, there is a single, global instance of the usb_address0
mutex which is used for all devices on all buses. This isn't completely
necessary, as this mutex is only needed to prevent address0 collisions for
devices on the *same* bus (usb 2.0 spec, sec 4.6.1). This superfluous coverage
can cause additional delay in system resume on systems with multiple hosts
(up to several seconds depending on what devices are attached).
Signed-off-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Not all host controller drivers have bus-suspend and bus-resume
methods. When one doesn't, it will cause problems if runtime PM is
enabled in the kernel. The PM core will attempt to suspend the
controller's root hub, the suspend will fail because there is no
bus-suspend routine, and a -EBUSY error code will be returned to the
PM core. This will cause the suspend attempt to be repeated shortly
thereafter, in a never-ending loop.
Part of the problem is that the original error code -ENOENT gets
changed to -EBUSY in usb_runtime_suspend(), on the grounds that the PM
core will interpret -ENOENT as meaning that the root hub has gotten
into a runtime-PM error state. While this change is appropriate for
real USB devices, it's not such a good idea for a root hub. In fact,
considering the root hub to be in a runtime-PM error state would not
be far from the truth. Therefore this patch updates
usb_runtime_suspend() so that it adjusts error codes only for
non-root-hub devices.
Furthermore, the patch attempts to prevent the problem from occurring
in the first place by not enabling runtime PM by default for root hubs
whose host controller driver doesn't have bus_suspend and bus_resume
methods.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Will Deacon <will.deacon@arm.com>
Tested-by: Will Deacon <will.deacon@arm.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here's the big USB pull request for 3.15-rc1.
The normal set of patches, lots of controller driver updates, and a
smattering of individual USB driver updates as well.
All have been in linux-next for a while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'usb-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB patches from Greg KH:
"Here's the big USB pull request for 3.15-rc1.
The normal set of patches, lots of controller driver updates, and a
smattering of individual USB driver updates as well.
All have been in linux-next for a while"
* tag 'usb-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (249 commits)
xhci: Transition maintainership to Mathias Nyman.
USB: disable reset-resume when USB_QUIRK_RESET is set
USB: unbind all interfaces before rebinding any
usb: phy: Add ulpi IDs for SMSC USB3320 and TI TUSB1210
usb: gadget: tcm_usb_gadget: stop format strings
usb: gadget: f_fs: add missing spinlock and mutex unlock
usb: gadget: composite: switch over to ERR_CAST()
usb: gadget: inode: switch over to memdup_user()
usb: gadget: f_subset: switch over to PTR_RET
usb: gadget: lpc32xx_udc: fix wrong clk_put() sequence
USB: keyspan: remove dead debugging code
USB: serial: add missing newlines to dev_<level> messages.
USB: serial: add missing braces
USB: serial: continue to write on errors
USB: serial: continue to read on errors
USB: serial: make bulk_out_size a lower limit
USB: cypress_m8: fix potential scheduling while atomic
devicetree: bindings: document lsi,zevio-usb
usb: chipidea: add support for USB OTG controller on LSI Zevio SoCs
usb: chipidea: imx: Use dev_name() for ci_hdrc name to distinguish USBs
...
Here's the huge drivers/staging/ update for 3.15-rc1.
Loads of cleanup fixes, a few drivers removed, and some new ones added.
All have been in linux-next for a while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'staging-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging driver updates from Greg KH:
"Here's the huge drivers/staging/ update for 3.15-rc1.
Loads of cleanup fixes, a few drivers removed, and some new ones
added.
All have been in linux-next for a while"
* tag 'staging-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (1375 commits)
staging: xillybus: XILLYBUS_PCIE depends on PCI_MSI
staging: xillybus: Added "select CRC32" for XILLYBUS in Kconfig
staging: comedi: poc: remove obsolete driver
staging: unisys: replace kzalloc/kfree with UISMALLOC/UISFREE
staging: octeon-usb: prevent memory corruption
staging: usbip: fix line over 80 characters
staging: usbip: fix quoted string split across lines
Staging: unisys: Remove RETINT macro
Staging: unisys: Remove FAIL macro
Staging: unisys: Remove RETVOID macro
Staging: unisys: Remove RETPTR macro
Staging: unisys: Remove RETBOOL macro
Staging: unisys: Remove FAIL_WPOSTCODE_1 macro
Staging: unisys: Cleanup macros to get rid of goto statements
Staging: unisys: include: Remove unused macros from timskmod.h
staging: dgap: fix the rest of the checkpatch warnings in dgap.c
Staging: bcm: Remove unnecessary parentheses
staging: wlags49_h2: Delete unnecessary braces
staging: wlags49_h2: Do not use assignment in if condition
staging: wlags49_h2: Enclose macro in a do-while loop
...
The USB_QUIRK_RESET flag indicates that a USB device changes its
identity in some way when it is reset. It may lose its firmware, its
descriptors may change, or it may switch back to a default mode of
operation.
If a device does this, the kernel needs to avoid resetting it. Resets
are likely to fail, or worse, succeed while changing the device's
state in a way the system can't detect.
This means we should disable the reset-resume mechanism whenever this
quirk flag is present. An attempted reset-resume will fail, the
device will be logically disconnected, and later on the hub driver
will rediscover and re-enumerate the device. This will cause the
appropriate udev events to be generated, so that userspace will have a
chance to switch the device into its normal operating mode, if
necessary.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Oliver Neukum <oliver@neukum.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a driver doesn't have pre_reset, post_reset, or reset_resume
methods, the USB core unbinds that driver when its device undergoes a
reset or a reset-resume, and then rebinds it afterward.
The existing straightforward implementation can lead to problems,
because each interface gets unbound and rebound before the next
interface is handled. If a driver claims additional interfaces, the
claim may fail because the old binding instance may still own the
additional interface when the new instance tries to claim it.
This patch fixes the problem by first unbinding all the interfaces
that are marked (i.e., their needs_binding flag is set) and then
rebinding all of them.
The patch also makes the helper functions in driver.c a little more
uniform and adjusts some out-of-date comments.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: "Poulain, Loic" <loic.poulain@intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since it is needed outside usbcore and exposed in include/linux/usb.h,
it conflicts with enum dev_state in rt2x00 wireless driver.
Mark it as usb specific to avoid conflicts in the future.
Signed-off-by: Valentina Manea <valentina.manea.m@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A device should not be able to be used concurrently both by
the server and the client. Claiming the port used by the
shared device ensures no interface drivers bind to it and
that it is not usable from the server.
Signed-off-by: Valentina Manea <valentina.manea.m@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
PREPARE_[DELAYED_]WORK() are being phased out. They have few users
and a nasty surprise in terms of reentrancy guarantee as workqueue
considers work items to be different if they don't have the same work
function.
usb_hub->init_work is multiplexed with multiple work functions;
however, the work item is never queued while in-flight, so we can
simply use INIT_DELAYED_WORK() before each queueing.
It would probably be best to route this with other related updates
through the workqueue tree.
Lightly tested.
v2: Greg and Alan confirm that the work item is never queued while
in-flight. Simply use INIT_DELAYED_WORK().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: linux-usb@vger.kernel.org
On disconnect USB3 protocol ports transit from U0 to SS.Inactive to Rx.Detect,
on a recoverable error, the port stays in SS.Inactive and we recover from it by
doing a warm-reset (through usb_device_reset if we have a udev for the port).
If this really is a disconnect we may end up trying the warm-reset anyways,
since khubd may run before the SS.Inactive to Rx.Detect transition, or it
may get skipped if the transition to Rx.Detect happens before khubd gets run.
With a loose connector, or in the case which actually led me to debugging this
bad ACPI firmware toggling Vbus off and on in quick succession, the port
may transition from Rx.Detect to U0 again before khubd gets run. In this case
the device state is unknown really, but khubd happily goes into the resuscitate
an existing device path, and the device driver never gets notified about the
device state being messed up.
If the above scenario happens with a streams using device, as soon as an urb
is submitted to an endpoint with streams, the following appears in dmesg:
ERROR Transfer event for disabled endpoint or incorrect stream ring
@0000000036807420 00000000 00000000 04000000 04078000
Notice how the TRB address is all zeros. I've seen this both on Intel
Pantherpoint and Nec xhci hosts.
Luckily we can detect the U0 to SS.Inactive to Rx.Detect to U0 all having
happened before khubd runs case since the C_LINK_STATE bit gets set in the
portchange bits on the U0 -> SS.Inactive change. This bit will also be set on
suspend / resume, but then it gets cleared by port_hub_init before khubd runs.
So if the C_LINK_STATE bit is set and a warm-reset is not needed, iow the port
is not still in SS.Inactive, and the port still has a connection, then the
device needs to be reset to put it back in a known state.
I've verified that doing the device reset also fixes the transfer event with
all zeros address issue.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
If streams are still allocated on device-reset or set-interface then the hcd
code implictly frees the streams. Clear host_endpoint->streams in this case
so that if a driver later tries to re-allocate them it won't run afoul of the
device already having streams check in usb_alloc_streams().
Note normally streams still being allocated at reset / set-intf would be a
driver bug, but this can happen without it being a driver bug on reset-resume.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
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
ae8963adb4 "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: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Better check the correct bit on big endian systems too. Shuts
up the following sparse __CHECK_ENDIAN__ warning:
.../hub.c:3965:32: warning: restricted __le32 degrades to integer
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This error case isn't reported during enumeration.
Signed-off-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Allow the scheduler to select the best CPU to handle hub initalization
and LED blinking work. This extends idle residency times on idle CPUs
and conserves power.
This functionality is enabled when CONFIG_WQ_POWER_EFFICIENT is selected.
[zoran.markovic@linaro.org: Rebased to latest kernel. Added commit message.
Changed reference from system to power efficient workqueue for LEDs in
check_highspeed() and hub_port_connect_change().]
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Xenia Ragiadakou <burzalodowa@gmail.com>
Cc: Julius Werner <jwerner@chromium.org>
Cc: Krzysztof Mazur <krzysiek@podlesie.net>
Cc: Matthias Beyer <mail@beyermatthias.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Shaibal Dutta <shaibal.dutta@broadcom.com>
Signed-off-by: Zoran Markovic <zoran.markovic@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 9df89d85b4 "usbcore: set
lpm_capable field for LPM capable root hubs" was created under the
assumption that all USB host controllers should have USB 3.0 Link PM
enabled for all devices under the hosts.
Unfortunately, that's not the case. The xHCI driver relies on knowledge
of the host hardware scheduler to calculate the LPM U1/U2 timeout
values, and it only sets lpm_capable to one for Intel host controllers
(that have the XHCI_LPM_SUPPORT quirk set).
When LPM is enabled for some Fresco Logic hosts, it causes failures with
a AgeStar 3UBT USB 3.0 hard drive dock:
Jan 11 13:59:03 sg-laptop kernel: usb 3-1: new SuperSpeed USB device number 2 using xhci_hcd
Jan 11 13:59:03 sg-laptop kernel: usb 3-1: Set SEL for device-initiated U1 failed.
Jan 11 13:59:08 sg-laptop kernel: usb 3-1: Set SEL for device-initiated U2 failed.
Jan 11 13:59:08 sg-laptop kernel: usb-storage 3-1:1.0: USB Mass Storage device detected
Jan 11 13:59:08 sg-laptop mtp-probe[613]: checking bus 3, device 2: "/sys/devices/pci0000:00/0000:00:1c.3/0000:04:00.0/usb3/3-1"
Jan 11 13:59:08 sg-laptop mtp-probe[613]: bus: 3, device: 2 was not an MTP device
Jan 11 13:59:08 sg-laptop kernel: scsi6 : usb-storage 3-1:1.0
Jan 11 13:59:13 sg-laptop kernel: usb 3-1: Set SEL for device-initiated U1 failed.
Jan 11 13:59:18 sg-laptop kernel: usb 3-1: Set SEL for device-initiated U2 failed.
Jan 11 13:59:18 sg-laptop kernel: usbcore: registered new interface driver usb-storage
Jan 11 13:59:40 sg-laptop kernel: usb 3-1: reset SuperSpeed USB device number 2 using xhci_hcd
Jan 11 13:59:41 sg-laptop kernel: usb 3-1: device descriptor read/8, error -71
Jan 11 13:59:41 sg-laptop kernel: usb 3-1: reset SuperSpeed USB device number 2 using xhci_hcd
Jan 11 13:59:46 sg-laptop kernel: usb 3-1: device descriptor read/8, error -110
Jan 11 13:59:46 sg-laptop kernel: scsi 6:0:0:0: Device offlined - not ready after error recovery
Jan 11 13:59:46 sg-laptop kernel: usb 3-1: USB disconnect, device number 2
lspci for the affected host:
04:00.0 0c03: 1b73:1000 (rev 04) (prog-if 30 [XHCI])
Subsystem: 1043:1039
Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
Latency: 0, Cache Line Size: 64 bytes
Interrupt: pin A routed to IRQ 19
Region 0: Memory at dd200000 (32-bit, non-prefetchable) [size=64K]
Capabilities: [50] Power Management version 3
Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold-)
Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
Capabilities: [68] MSI: Enable- Count=1/1 Maskable- 64bit+
Address: 0000000000000000 Data: 0000
Capabilities: [80] Express (v1) Endpoint, MSI 00
DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <2us, L1 <32us
ExtTag- AttnBtn- AttnInd- PwrInd- RBE+ FLReset-
DevCtl: Report errors: Correctable- Non-Fatal- Fatal- Unsupported-
RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+
MaxPayload 128 bytes, MaxReadReq 512 bytes
DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr- TransPend-
LnkCap: Port #0, Speed 2.5GT/s, Width x1, ASPM L0s L1, Latency L0 unlimited, L1 unlimited
ClockPM- Surprise- LLActRep- BwNot-
LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk+
ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
LnkSta: Speed 2.5GT/s, Width x1, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
Kernel driver in use: xhci_hcd
Kernel modules: xhci_hcd
The commit was backported to stable kernels, and will need to be
reverted there as well.
Signed-off-by: Sarah Sharp <sarah.a.sharp@intel.com>
Reported-by: Sergey Galanov <sergey.e.galanov@gmail.com>
Cc: stable@vger.kernel.org
When we are doing compliance test with xHCI, we found that if we
enable CONFIG_USB_SUSPEND and plug in a bad device which causes
over-current condition to the root port, software will not be noticed.
The reason is that current code don't set hub->change_bits in
hub_activate() when over-current happens, and then hub_events() will
not check the port status because it thinks nothing changed.
If CONFIG_USB_SUSPEND is disabled, the interrupt pipe of the hub will
report the change and set hub->event_bits, and then hub_events() will
check what events happened.In this case over-current can be detected.
Signed-off-by: Shen Guang <shenguang10@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is a race in the hub driver between hub_disconnect() and
recursively_mark_NOTATTACHED(). This race can be triggered if the
driver is unbound from a device at the same time as the bus's root hub
is removed. When the race occurs, it can cause an oops:
BUG: unable to handle kernel NULL pointer dereference at 0000015c
IP: [<c16d5fb0>] recursively_mark_NOTATTACHED+0x20/0x60
Call Trace:
[<c16d5fc4>] recursively_mark_NOTATTACHED+0x34/0x60
[<c16d5fc4>] recursively_mark_NOTATTACHED+0x34/0x60
[<c16d5fc4>] recursively_mark_NOTATTACHED+0x34/0x60
[<c16d5fc4>] recursively_mark_NOTATTACHED+0x34/0x60
[<c16d6082>] usb_set_device_state+0x92/0x120
[<c16d862b>] usb_disconnect+0x2b/0x1a0
[<c16dd4c0>] usb_remove_hcd+0xb0/0x160
[<c19ca846>] ? _raw_spin_unlock_irqrestore+0x26/0x50
[<c1704efc>] ehci_mid_remove+0x1c/0x30
[<c1704f26>] ehci_mid_stop_host+0x16/0x30
[<c16f7698>] penwell_otg_work+0xd28/0x3520
[<c19c945b>] ? __schedule+0x39b/0x7f0
[<c19cdb9d>] ? sub_preempt_count+0x3d/0x50
[<c125e97d>] process_one_work+0x11d/0x3d0
[<c19c7f4d>] ? mutex_unlock+0xd/0x10
[<c125e0e5>] ? manage_workers.isra.24+0x1b5/0x270
[<c125f009>] worker_thread+0xf9/0x320
[<c19ca846>] ? _raw_spin_unlock_irqrestore+0x26/0x50
[<c125ef10>] ? rescuer_thread+0x2b0/0x2b0
[<c1264ac4>] kthread+0x94/0xa0
[<c19d0f77>] ret_from_kernel_thread+0x1b/0x28
[<c1264a30>] ? kthread_create_on_node+0xc0/0xc0
One problem is that recursively_mark_NOTATTACHED() uses the intfdata
value and hub->hdev->maxchild while hub_disconnect() is clearing them.
Another problem is that it uses hub->ports[i] while the port device is
being released.
To fix this race, we need to hold the device_state_lock while
hub_disconnect() changes the values. (Note that usb_disconnect()
and hub_port_connect_change() already acquire this lock at similar
critical times during a USB device's life cycle.) We also need to
remove the port devices after maxchild has been set to 0, instead of
before.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: "Du, Changbin" <changbinx.du@intel.com>
Tested-by: "Du, Changbin" <changbinx.du@intel.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CONFIG_USB_DEBUG is going away, so remove the few places in the USB core
that relied on them.
This means that we always now do the "debug" checks for every urb
submitted, which is a good idea, as who knows how many driver bugs we
have been ignoring when people forget to enable this option. Also, with
the overall speed of USB, doing these extra checks should not cause any
additional overhead.
Also, no longer announce all devices being added to the system if
CONFIG_USB_DEBUG is enabled, as it's not going to be around much longer.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Change the default enumeration scheme for xhci attached non-SuperSpeed
devices from:
Reset
SetAddress [xhci address-device BSR = 0]
GetDescriptor(8)
GetDescriptor(18)
...to:
Reset
[xhci address-device BSR = 1]
GetDescriptor(64)
Reset
SetAddress [xhci address-device BSR = 0]
GetDescriptor(18)
...as some devices misbehave when encountering a SetAddress command
prior to GetDescriptor. There are known legacy devices that require
this scheme, but testing has found at least one USB3 device that fails
enumeration when presented with this ordering. For now, follow the ehci
case and enable 'new scheme' by default for non-SuperSpeed devices.
To support this enumeration scheme on xhci the AddressDevice operation
needs to be performed twice. The first instance of the command enables
the HC's device and slot context info for the device, but omits sending
the device a SetAddress command (BSR == block set address request).
Then, after GetDescriptor completes, follow up with the full
AddressDevice+SetAddress operation.
As mentioned before, this ordering of events with USB3 devices causes an
extra state transition to be exposed to xhci. Previously USB3 devices
would transition directly from 'enabled' to 'addressed' and never need
to underrun responses to 'get descriptor'. We do see the 64-byte
descriptor fetch the correct data, but the following 18-byte descriptor
read after the reset gets:
bLength = 0
bDescriptorType = 0
bcdUSB = 0
bDeviceClass = 0
bDeviceSubClass = 0
bDeviceProtocol = 0
bMaxPacketSize0 = 9
instead of:
bLength = 12
bDescriptorType = 1
bcdUSB = 300
bDeviceClass = 0
bDeviceSubClass = 0
bDeviceProtocol = 0
bMaxPacketSize0 = 9
which results in the discovery process looping until falling back to
'old scheme' enumeration.
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: David Moore <david.moore@gmail.com>
Suggested-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
There is no need to skip querying the config and string descriptors for
unauthorized WUSB devices when usb_new_device is called. It is allowed
by WUSB spec. The only action that needs to be delayed until
authorization time is the set config. This change allows user mode
tools to see the config and string descriptors earlier in enumeration
which is needed for some WUSB devices to function properly on Android
systems. It also reduces the amount of divergent code paths needed
for WUSB devices.
Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch adds a check for USB_STATE_NOTATTACHED to the
hub_port_warm_reset_required() workaround for ports that end up in
Compliance Mode in hub_events() when trying to decide which reset
function to use. Trying to call usb_reset_device() with a NOTATTACHED
device will just fail and leave the port broken.
Signed-off-by: Julius Werner <jwerner@chromium.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since DEVICE_ACPI_HANDLE() is now literally identical to
ACPI_HANDLE(), replace it with the latter everywhere and drop its
definition from include/acpi.h.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Hi Greg,
Here's my pull request for usb-next and 3.13. My xHCI tree is closed
after this point, since I won't be able to run my full tests while I'm in
Scotland. After Kernel Summit, I'll be on vacation with access to email
from Oct 26th to Nov 6th.
Here's what's in this request:
- Patches to fix USB 2.0 Link PM issues that cause USB 3.0 devices to not
enumerate or misbehave when plugged into a USB 2.0 port. Those are
marked for stable.
- A msec vs jiffies bug fix by xiao jin, which results in fairly harmless
behavior, and thus isn't marked for stable.
- Xenia's patches to refactor the xHCI command handling code, which makes
it much more readable and consistent.
- Misc cleanup patches, one by Sachin Kamat and three from Dan Williams.
Here's what's not in this request:
- Dan's two patches to allow the xHCI host to use the "Windows" or "new"
enumeration scheme. I did not have time to test those, and I want to
run them with as many USB devices as I can get a hold of. That will
have to wait for 3.14.
- Xenia's patches to remove xhci_readl in favor of readl. I'll queue
those for 3.14 after I test them.
- The xHCI streams update, UAS fixes, and usbfs streams support. I'm not
comfortable with changes and fixes to that patchset coming in this late.
I would rather wait for 3.14 and be really sure the streams support is
stable before we add new userspace API and remove CONFIG_BROKEN from the
uas driver.
- Julius' patch to clear the port reset bit on hub resume that came in
a couple days ago. It looks harmless, but I would rather take the time
to test and queue it for usb-linus and the stable trees once 3.13-rc1
is out.
Sarah Sharp
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Merge tag 'for-usb-next-2013-10-17' of git://git.kernel.org/pub/scm/linux/kernel/git/sarah/xhci into usb-next
Sarah writes:
xhci: Final patches for 3.13
Hi Greg,
Here's my pull request for usb-next and 3.13. My xHCI tree is closed
after this point, since I won't be able to run my full tests while I'm in
Scotland. After Kernel Summit, I'll be on vacation with access to email
from Oct 26th to Nov 6th.
Here's what's in this request:
- Patches to fix USB 2.0 Link PM issues that cause USB 3.0 devices to not
enumerate or misbehave when plugged into a USB 2.0 port. Those are
marked for stable.
- A msec vs jiffies bug fix by xiao jin, which results in fairly harmless
behavior, and thus isn't marked for stable.
- Xenia's patches to refactor the xHCI command handling code, which makes
it much more readable and consistent.
- Misc cleanup patches, one by Sachin Kamat and three from Dan Williams.
Here's what's not in this request:
- Dan's two patches to allow the xHCI host to use the "Windows" or "new"
enumeration scheme. I did not have time to test those, and I want to
run them with as many USB devices as I can get a hold of. That will
have to wait for 3.14.
- Xenia's patches to remove xhci_readl in favor of readl. I'll queue
those for 3.14 after I test them.
- The xHCI streams update, UAS fixes, and usbfs streams support. I'm not
comfortable with changes and fixes to that patchset coming in this late.
I would rather wait for 3.14 and be really sure the streams support is
stable before we add new userspace API and remove CONFIG_BROKEN from the
uas driver.
- Julius' patch to clear the port reset bit on hub resume that came in
a couple days ago. It looks harmless, but I would rather take the time
to test and queue it for usb-linus and the stable trees once 3.13-rc1
is out.
Sarah Sharp
Remove a few extra lines and make it clear that all implementations
disable the port by sharing the same line of code.
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
This patch adds the Port Reset Change flag to the set of bits that are
preemptively cleared on init/resume of a hub. In theory this bit should
never be set unexpectedly... in practice it can still happen if BIOS,
SMM or ACPI code plays around with USB devices without cleaning up
correctly. This is especially dangerous for XHCI root hubs, which don't
generate any more Port Status Change Events until all change bits are
cleared, so this is a good precaution to have (similar to how it's
already done for the Warm Port Reset Change flag).
Signed-off-by: Julius Werner <jwerner@chromium.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some usb3 devices falsely claim they support usb2 hardware Link PM
when connected to a usb2 port. We only trust hardwired devices
or devices with the later BESL LPM support to be LPM enabled as default.
[Note: Sarah re-worked the original patch to move the code into the USB
core, and updated it to check whether the USB device supports BESL,
instead of checking if the xHCI port it's connected to supports BESL
encoding.]
This patch should be backported to kernels as old as 3.11, that
contain the commit a558ccdcc7 "usb: xhci:
add USB2 Link power management BESL support". Without this fix, some
USB 3.0 devices will not enumerate or work properly under USB 2.0 ports
on Haswell-ULT systems.
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org
How it's supposed to work:
--------------------------
USB 2.0 Link PM is a lower power state that some newer USB 2.0 devices
support. USB 3.0 devices certified by the USB-IF are required to
support it if they are plugged into a USB 2.0 only port, or a USB 2.0
cable is used. USB 2.0 Link PM requires both a USB device and a host
controller that supports USB 2.0 hardware-enabled LPM.
USB 2.0 Link PM is designed to be enabled once by software, and the host
hardware handles transitions to the L1 state automatically. The premise
of USB 2.0 Link PM is to be able to put the device into a lower power
link state when the bus is idle or the device NAKs USB IN transfers for
a specified amount of time.
...but hardware is broken:
--------------------------
It turns out many USB 3.0 devices claim to support USB 2.0 Link PM (by
setting the LPM bit in their USB 2.0 BOS descriptor), but they don't
actually implement it correctly. This manifests as the USB device
refusing to respond to transfers when it is plugged into a USB 2.0 only
port under the Haswell-ULT/Lynx Point LP xHCI host.
These devices pass the xHCI driver's simple test to enable USB 2.0 Link
PM, wait for the port to enter L1, and then bring it back into L0. They
only start to break when L1 entry is interleaved with transfers.
Some devices then fail to respond to the next control transfer (usually
a Set Configuration). This results in devices never enumerating.
Other mass storage devices (such as a later model Western Digital My
Passport USB 3.0 hard drive) respond fine to going into L1 between
control transfers. They ACK the entry, come out of L1 when the host
needs to send a control transfer, and respond properly to those control
transfers. However, when the first READ10 SCSI command is sent, the
device NAKs the data phase while it's reading from the spinning disk.
Eventually, the host requests to put the link into L1, and the device
ACKs that request. Then it never responds to the data phase of the
READ10 command. This results in not being able to read from the drive.
Some mass storage devices (like the Corsair Survivor USB 3.0 flash
drive) are well behaved. They ACK the entry into L1 during control
transfers, and when SCSI commands start coming in, they NAK the requests
to go into L1, because they need to be at full power.
Not all USB 3.0 devices advertise USB 2.0 link PM support. My Point
Grey USB 3.0 webcam advertises itself as a USB 2.1 device, but doesn't
have a USB 2.0 BOS descriptor, so we don't enable USB 2.0 Link PM. I
suspect that means the device isn't certified.
What do we do about it?
-----------------------
There's really no good way for the kernel to test these devices.
Therefore, the kernel needs to disable USB 2.0 Link PM by default, and
distros will have to enable it by writing 1 to the sysfs file
/sys/bus/usb/devices/../power/usb2_hardware_lpm. Rip out the xHCI Link
PM test, since it's not sufficient to detect these buggy devices, and
don't automatically enable LPM after the device is addressed.
This patch should be backported to kernels as old as 3.11, that
contain the commit a558ccdcc7 "usb: xhci:
add USB2 Link power management BESL support". Without this fix, some
USB 3.0 devices will not enumerate or work properly under USB 2.0 ports
on Haswell-ULT systems.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org
Before the USB core resets a device, we need to disable the L1 timeout
for the roothub, if USB 2.0 Link PM is enabled. Otherwise the port may
transition into L1 in between descriptor fetches, before we know if the
USB device descriptors changed. LPM will be re-enabled after the
full device descriptors are fetched, and we can confirm the device still
supports USB 2.0 LPM after the reset.
We don't need to wait for the USB device to exit L1 before resetting the
device, since the xHCI roothub port diagrams show a transition to the
Reset state from any of the Ux states (see Figure 34 in the 2012-08-14
xHCI specification update).
This patch should be backported to kernels as old as 3.2, that contain
the commit 65580b4321 "xHCI: set USB2
hardware LPM". That was the first commit to enable USB 2.0
hardware-driven Link Power Management.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org
