The steps taken by usb core to set a new interface is very different from
what is done on the xHC host side.
xHC hardware will do everything in one go. One command is used to set up
new endpoints, free old endpoints, check bandwidth, and run the new
endpoints.
All this is done by xHC when usb core asks the hcd to check for
available bandwidth. At this point usb core has not yet flushed the old
endpoints, which will cause use-after-free issues in xhci driver as
queued URBs are cancelled on a re-allocated endpoint.
To resolve this add a call to usb_disable_interface() which will flush
the endpoints before calling usb_hcd_alloc_bandwidth()
Additional checks in xhci driver will also be implemented to gracefully
handle stale URB cancel on freed and re-allocated endpoints
Cc: <stable@vger.kernel.org>
Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The USB completion callback does not disable interrupts while acquiring
the lock. We want to remove the local_irq_disable() invocation from
__usb_hcd_giveback_urb() and therefore it is required for the callback
handler to disable the interrupts while acquiring the lock.
The callback may be invoked either in IRQ or BH context depending on the
USB host controller.
Use the _irqsave() variant of the locking primitives.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
No need to do extra endianness conversion in
usb_set_isoch_delay because it is already done
in usb_control_msg()
Fixes: 886ee36e72 ("usb: core: add support for USB_REQ_SET_ISOCH_DELAY")
Cc: Dmytro Panchenko <dmytro.panchenko@globallogic.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: stable <stable@vger.kernel.org> # v4.16+
Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Corsair Strafe RGB keyboard does not respond to usb control messages
sometimes and hence generates timeouts.
Commit de3af5bf25 ("usb: quirks: add delay init quirk for Corsair
Strafe RGB keyboard") tried to fix those timeouts by adding
USB_QUIRK_DELAY_INIT.
Unfortunately, even with this quirk timeouts of usb_control_msg()
can still be seen, but with a lower frequency (approx. 1 out of 15):
[ 29.103520] usb 1-8: string descriptor 0 read error: -110
[ 34.363097] usb 1-8: can't set config #1, error -110
Adding further delays to different locations where usb control
messages are issued just moves the timeouts to other locations,
e.g.:
[ 35.400533] usbhid 1-8:1.0: can't add hid device: -110
[ 35.401014] usbhid: probe of 1-8:1.0 failed with error -110
The only way to reliably avoid those issues is having a pause after
each usb control message. In approx. 200 boot cycles no more timeouts
were seen.
Addionaly, keep USB_QUIRK_DELAY_INIT as it turned out to be necessary
to have the delay in hub_port_connect() after hub_port_init().
The overall boot time seems not to be influenced by these additional
delays, even on fast machines and lightweight distributions.
Fixes: de3af5bf25 ("usb: quirks: add delay init quirk for Corsair Strafe RGB keyboard")
Cc: stable@vger.kernel.org
Signed-off-by: Danilo Krummrich <danilokrummrich@dk-develop.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB SS and SSP hubs provide wHubDelay values on their hub descriptor
which we should inform the USB Device about.
The USB Specification 3.0 explains, on section 9.4.11, how to
calculate the value and how to issue the request. Note that a
USB_REQ_SET_ISOCH_DELAY is valid on all device states (Default,
Address, Configured), we just *chose* to issue it from Address state
right after successfully fetching the USB Device Descriptor.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Using a period after a newline causes bad output.
Miscellanea:
o Coalesce formats too
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add OF device-tree support for USB interfaces.
USB "interface nodes" are children of USB "device nodes" and are
identified by an interface number and a configuration value:
&usb1 { /* host controller */
dev1: device@1 { /* device at port 1 */
compatible = "usb1234,5678";
reg = <1>;
#address-cells = <2>;
#size-cells = <0>;
interface@0,2 { /* interface 0 of configuration 2 */
compatible = "usbif1234,5678.config2.0";
reg = <0 2>;
};
};
};
The configuration component is not included in the textual
representation of an interface-node unit address for configuration 1:
&dev1 {
interface@0 { /* interface 0 of configuration 1 */
compatible = "usbif1234,5678.config1.0";
reg = <0 1>;
};
};
When a USB device of class 0 or 9 (hub) has only a single configuration
with a single interface, a special case "combined node" is used instead
of a device node with an interface node:
&usb1 {
device@2 {
compatible = "usb1234,abcd";
reg = <2>;
};
};
Combined nodes are shared by the two device structures representing the
USB device and its interface in the kernel's device model.
Note that, as for device nodes, the compatible strings for interface
nodes are currently not used.
For more details see "Open Firmware Recommended Practice: Universal
Serial Bus Version 1" and the binding documentation.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB devices should work just fine when they don't support language id.
Lower the log level so user won't panic in the future.
BugLink: https://bugs.launchpad.net/bugs/1729618
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb_control_msg() will return the amount of bytes transferred, if that
amount matches what we wanted to transfer, we need to reset 'ret' to 0
from usb_get_status().
Fixes: 2e43f0fe37 ("usb: core: add a 'type' parameter to usb_get_status()")
Reported-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This new 'type' parameter will allows interested drivers to request
for PTM status or Standard status.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This makes it a lot clearer that we're expecting a recipient as the
argument. A follow-up patch will use the argument 'type' as the status
type selector (standard or ptm).
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB 3.1 added a PTM_STATUS type. Let's add a define for it and
following patches will let usb_get_status() accept the new argument.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To match the rest of the kernel, the SPDX tags for the drivers/usb/core/
files are moved to the first line of the file. This makes it more
obvious the tag is present as well as making it match the other 12k
files in the tree with this location.
It also uses // to match the "expected style" as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Andrey Konovalov reported a possible out-of-bounds problem for the
cdc_parse_cdc_header function. He writes:
It looks like cdc_parse_cdc_header() doesn't validate buflen
before accessing buffer[1], buffer[2] and so on. The only check
present is while (buflen > 0).
So fix this issue up by properly validating the buffer length matches
what the descriptor says it is.
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We need an space before a numbered list to avoid those warnings:
./drivers/usb/core/message.c:478: ERROR: Unexpected indentation.
./drivers/usb/core/message.c:479: WARNING: Block quote ends without a blank line; unexpected unindent.
./include/linux/usb/composite.h:455: ERROR: Unexpected indentation.
./include/linux/usb/composite.h:456: WARNING: Block quote ends without a blank line; unexpected unindent.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The commonly use of bottom halves are tasklet and workqueue. The big
difference between tasklet and workqueue is that the tasklet runs in
an interrupt context and the workqueue runs in a process context,
which means it can sleep if need be.
The comment for usb_control/interrupt/bulk_msg() functions note that do
not use this function within an interrupt context, like a 'bottom half'
handler. With this comment, it makes confuse about usage of these
functions.
To more clarify, remove 'bottom half' comment.
Signed-off-by: Jaejoong Kim <climbbb.kim@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some of the USB core files were missing explicit license information.
As all files in the kernel tree are implicitly licensed under the
GPLv2-only, be explicit in case someone get confused looking at
individual files by using the SPDX nomenclature.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If dma_pfn_offset is not inherited correctly from the host controller,
it might result in sub-optimal configuration as bounce
buffer limit might be set to less than optimal level.
Consider the mass storage device case.
USB storage driver creates a scsi host for the mass storage interface in
drivers/usb/storage/usb.c
The scsi host parent device is nothing but the the USB interface device.
Now, __scsi_init_queue() calls scsi_calculate_bounce_limit() to find out
and set the block layer bounce limit.
scsi_calculate_bounce_limit() uses dma_max_pfn(host_dev) to get the
bounce_limit. host_dev is nothing but the device representing the
mass storage interface.
If that device doesn't have the right dma_pfn_offset, then dma_max_pfn()
is messed up and the bounce buffer limit is wrong.
e.g. On Keystone 2 systems, dma_max_pfn() is 0x87FFFF and dma_mask_pfn
is 0xFFFFF. Consider a mass storage use case: Without this patch,
usb scsi host device (usb-storage) will get a dma_pfn_offset of 0 resulting
in a dma_max_pfn() of 0xFFFFF within the scsi layer
(scsi_calculate_bounce_limit()).
This will result in bounce buffers being unnecessarily used.
Hint: On 32-bit ARM platforms dma_max_pfn() = dma_mask_pfn + dma_pfn_offset
Signed-off-by: Roger Quadros <rogerq@ti.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
All kmalloc-based functions print enough information on failures.
Signed-off-by: Wolfram Sang <wsa-dev@sang-engineering.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The dependencies were impossible to handle preventing
drivers for CDC devices not which are not network drivers
from using the common parser.
Signed-off-by: Oliver Neukum <ONeukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Restructure usb_sg_cancel() so we don't have to disable interrupts
while cancelling the URBs.
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: David Mosberger <davidm@egauge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb_submit_urb() may take quite long to execute. For example, a
single sg list may have 30 or more entries, possibly leading to that
many calls to DMA-map pages. This can cause interrupt latency of
several hundred micro-seconds.
Avoid the problem by releasing the io->lock spinlock and re-enabling
interrupts before calling usb_submit_urb(). This opens races with
usb_sg_cancel() and sg_complete(). Handle those races by using
usb_block_urb() to stop URBs from being submitted after
usb_sg_cancel() or sg_complete() with error.
Note that usb_unlink_urb() is guaranteed to return -ENODEV if
!io->urbs[i]->dev and since the -ENODEV case is already handled,
we don't have to check for !io->urbs[i]->dev explicitly.
Before this change, reading 512MB from an ext3 filesystem on a USB
memory stick showed a throughput of 12 MB/s with about 500 missed
deadlines.
With this change, reading the same file gave the same throughput but
only one or two missed deadlines.
Signed-off-by: David Mosberger <davidm@egauge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix the Sparse warning:
message.c:1390:21: warning: symbol 'i' shadows an earlier one
message.c:1294:13: originally declared here
Signed-off-by: Kris Borer <kborer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The kernel supports the device authorization because of wireless USB.
These is usable for wired USB devices, too.
These new interface authorization allows to enable or disable
individual interfaces instead a whole device.
If a deauthorized interface will be authorized so the driver probing must
be triggered manually by writing INTERFACE to /sys/bus/usb/drivers_probe
Signed-off-by: Stefan Koch <stefan.koch10@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Interfaces are allowed per default.
This can disabled or enabled (again) by writing 0 or 1 to
/sys/bus/usb/devices/usbX/interface_authorized_default
Signed-off-by: Stefan Koch <stefan.koch10@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The USB stack provides a mechanism for drivers to request an
asynchronous device reset (usb_queue_reset_device()). The mechanism
uses a work item (reset_ws) embedded in the usb_interface structure
used by the driver, and the reset is carried out by a work queue
routine.
The asynchronous reset can race with driver unbinding. When this
happens, we try to cancel the queued reset before unbinding the
driver, on the theory that the driver won't care about any resets once
it is unbound.
However, thanks to the fact that lockdep now tracks work queue
accesses, this can provoke a lockdep warning in situations where the
device reset causes another interface's driver to be unbound; see
http://marc.info/?l=linux-usb&m=141893165203776&w=2
for an example. The reason is that the work routine for reset_ws in
one interface calls cancel_queued_work() for the reset_ws in another
interface. Lockdep thinks this might lead to a work routine trying to
cancel itself. The simplest solution is not to cancel queued resets
when unbinding drivers.
This means we now need to acquire a reference to the usb_interface
when queuing a reset_ws work item and to drop the reference when the
work routine finishes. We also need to make sure that the
usb_interface structure doesn't outlive its parent usb_device; this
means acquiring and dropping a reference when the interface is created
and destroyed.
In addition, cancelling a queued reset can fail (if the device is in
the middle of an earlier reset), and this can cause usb_reset_device()
to try to rebind an interface that has been deallocated (see
http://marc.info/?l=linux-usb&m=142175717016628&w=2 for details).
Acquiring the extra references prevents this failure.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Russell King - ARM Linux <linux@arm.linux.org.uk>
Reported-by: Olivier Sobrie <olivier@sobrie.be>
Tested-by: Olivier Sobrie <olivier@sobrie.be>
Cc: stable <stable@vger.kernel.org> # 3.19
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 0cce2eda19
USB: fix LANGID=0 regression
defaults to a langid of 0x0409 if it's not properly implemented by the
device. Explain with a higher level error message what this means.
Signed-off-by: Scot Doyle <lkml14@scotdoyle.com>
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
...
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>
This patch fix spelling typo in Documentation/DocBook.
It is because .html and .xml files are generated by make htmldocs,
I have to fix a typo within the source files.
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This driver was previously an interface driver. Since USB/IP
exports a whole device, not just an interface, it would make
sense to be a device driver.
This patch also modifies the way userspace sees and uses a
shared device:
* the usbip_status file is no longer created for interface 0, but for
the whole device (such as
/sys/devices/pci0000:00/0000:00:01.2/usb1/1-1/usbip_status).
* per interface information, such as interface class or protocol, is
no longer sent/received; only device specific information is
transmitted.
* since the driver was moved one level below in the USB architecture,
there is no need to bind/unbind each interface, just the device as a
whole.
Signed-off-by: Valentina Manea <valentina.manea.m@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>. Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The USB core currently handles enabling and disabling optional USB power
management features during device transitions (device suspend/resume,
driver bind/unbind, device reset, and device disconnect). Those
optional power features include Latency Tolerance Messaging (LTM),
USB 3.0 Link PM, and USB 2.0 Link PM.
The USB core currently enables LPM on device enumeration and disables
USB 2.0 Link PM when the device is reset. However, the xHCI driver
disables LPM when the device is disconnected and the device context is
freed. Push the call up into the USB core, in order to be consistent
with the core handling all power management enabling and disabling.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
When building the htmldocs (in verbose mode), scripts/kernel-doc reports the
following type of warnings:
Warning(drivers/usb/core/usb.c:76): No description found for return value of
'usb_find_alt_setting'
Fix them by:
- adding some missing descriptions of return values
- using "Return" sections for those descriptions
Signed-off-by: Yacine Belkadi <yacine.belkadi.1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch simplifies the interface presented by usb_get_status().
Instead of forcing callers to check for the proper data length and
convert the status value to host byte order, the function will now
do these things itself.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes parenthesis error in sizeof function in Usb/message.c
Signed-off-by: Tülin İzer <tulinizer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes error: 'no space before bracket' in Usb/message.c
Signed-off-by: Tülin İzer <tulinizer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The USB 2.0 specification says that bMaxPower is the maximum power
consumption expressed in 2 mA units and the USB 3.0 specification says
that it is expressed in 8 mA units.
This patch adds a helper function usb_get_max_power() which computes the
value based on config & usb_device's speed value. The the device descriptor
dump computes the value on its own.
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
'new_interfaces' should be freed to avoid memory leak.
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove conditional code based on CONFIG_HOTPLUG being false. It's
always on now in preparation of it going away as an option.
Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch (as1631) fixes a bug that shows up when a config change
fails for a device under an xHCI controller. The controller needs to
be told to disable the endpoints that have been enabled for the new
config. The existing code does this, but before storing the
information about which endpoints were enabled! As a result, any
second attempt to install the new config is doomed to fail because
xhci-hcd will refuse to enable an endpoint that is already enabled.
The patch optimistically initializes the new endpoints' device
structures before asking the device to switch to the new config. If
the request fails then the endpoint information is already stored, so
we can use usb_hcd_alloc_bandwidth() to disable the endpoints with no
trouble. The rest of the error path is slightly more complex now; we
have to disable the new interfaces and call put_device() rather than
simply deallocating them.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: Matthias Schniedermeyer <ms@citd.de>
CC: Sarah Sharp <sarah.a.sharp@linux.intel.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It's not needed, and commented out, so just remove it.
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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
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
This lets us catch the USB fixes that went into 3.5-rc3 into this branch,
as we want them here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Mathias Nyman