linux-toradex.git/include/linux/usb.h, branch v4.11-rc3

usb: fix a typo in usb_class_driver documentation

2016-10-24T12:36:25+00:00

replace usb_unregister_dev by usb_deregister_dev

Signed-off-by: Amitesh Singh 
Signed-off-by: Greg Kroah-Hartman

USB: leave LPM alone if possible when binding/unbinding interface drivers

2016-05-03T21:32:07+00:00

When a USB driver is bound to an interface (either through probing or
by claiming it) or is unbound from an interface, the USB core always
disables Link Power Management during the transition and then
re-enables it afterward.  The reason is because the driver might want
to prevent hub-initiated link power transitions, in which case the HCD
would have to recalculate the various LPM parameters.  This
recalculation takes place when LPM is re-enabled and the new
parameters are sent to the device and its parent hub.

However, if the driver does not want to prevent hub-initiated link
power transitions then none of this work is necessary.  The parameters
don't need to be recalculated, and LPM doesn't need to be disabled and
re-enabled.

It turns out that disabling and enabling LPM can be time-consuming,
enough so that it interferes with user programs that want to claim and
release interfaces rapidly via usbfs.  Since the usbfs kernel driver
doesn't set the disable_hub_initiated_lpm flag, we can speed things up
and get the user programs to work by leaving LPM alone whenever the
flag isn't set.

And while we're improving the way disable_hub_initiated_lpm gets used,
let's also fix its kerneldoc.

Signed-off-by: Alan Stern 
Tested-by: Matthew Giassa 
CC: Mathias Nyman 
CC: 
Signed-off-by: Greg Kroah-Hartman

usb: core: hub: hub_port_init lock controller instead of bus

2016-04-28T19:40:46+00:00

The XHCI controller presents two USB buses to the system - one for USB2
and one for USB3. The hub init code (hub_port_init) is reentrant but
only locks one bus per thread, leading to a race condition failure when
two threads attempt to simultaneously initialise a USB2 and USB3 device:

[    8.034843] xhci_hcd 0000:00:14.0: Timeout while waiting for setup device command
[   13.183701] usb 3-3: device descriptor read/all, error -110

On a test system this failure occurred on 6% of all boots.

The call traces at the point of failure are:

Call Trace:
 [] schedule+0x37/0x90
 [] usb_kill_urb+0x8d/0xd0
 [] ? wake_up_atomic_t+0x30/0x30
 [] usb_start_wait_urb+0xbe/0x150
 [] usb_control_msg+0xbc/0xf0
 [] hub_port_init+0x51e/0xb70
 [] hub_event+0x817/0x1570
 [] process_one_work+0x1ff/0x620
 [] ? process_one_work+0x15f/0x620
 [] worker_thread+0x64/0x4b0
 [] ? rescuer_thread+0x390/0x390
 [] kthread+0x105/0x120
 [] ? kthread_create_on_node+0x200/0x200
 [] ret_from_fork+0x3f/0x70
 [] ? kthread_create_on_node+0x200/0x200

Call Trace:
 [] xhci_setup_device+0x53d/0xa40
 [] xhci_address_device+0xe/0x10
 [] hub_port_init+0x1bf/0xb70
 [] ? trace_hardirqs_on+0xd/0x10
 [] hub_event+0x817/0x1570
 [] process_one_work+0x1ff/0x620
 [] ? process_one_work+0x15f/0x620
 [] worker_thread+0x64/0x4b0
 [] ? rescuer_thread+0x390/0x390
 [] kthread+0x105/0x120
 [] ? kthread_create_on_node+0x200/0x200
 [] ret_from_fork+0x3f/0x70
 [] ? kthread_create_on_node+0x200/0x200

Which results from the two call chains:

hub_port_init
 usb_get_device_descriptor
  usb_get_descriptor
   usb_control_msg
    usb_internal_control_msg
     usb_start_wait_urb
      usb_submit_urb / wait_for_completion_timeout / usb_kill_urb

hub_port_init
 hub_set_address
  xhci_address_device
   xhci_setup_device

Mathias Nyman explains the current behaviour violates the XHCI spec:

 hub_port_reset() will end up moving the corresponding xhci device slot
 to default state.

 As hub_port_reset() is called several times in hub_port_init() it
 sounds reasonable that we could end up with two threads having their
 xhci device slots in default state at the same time, which according to
 xhci 4.5.3 specs still is a big no no:

 "Note: Software shall not transition more than one Device Slot to the
  Default State at a time"

 So both threads fail at their next task after this.
 One fails to read the descriptor, and the other fails addressing the
 device.

Fix this in hub_port_init by locking the USB controller (instead of an
individual bus) to prevent simultaneous initialisation of both buses.

Fixes: 638139eb95d2 ("usb: hub: allow to process more usb hub events in parallel")
Link: https://lkml.org/lkml/2016/2/8/312
Link: https://lkml.org/lkml/2016/2/4/748
Signed-off-by: Chris Bainbridge 
Cc: stable 
Acked-by: Mathias Nyman 
Signed-off-by: Greg Kroah-Hartman

USB: correct intervals for SS+

2016-04-26T22:04:38+00:00

SS+ also expresses intervals in units of 125ms. Testing must
be for SS or faster, not SS exactly.

Signed-off-by: Oliver neukum 
Signed-off-by: Greg Kroah-Hartman

USB: LTM also for USB 3.1

2016-04-26T22:04:38+00:00

LTM is also defined for SS+. The correct test is to check for anything
slower than SS not exactly SS.

Signed-off-by: Oliver Neukum 
Signed-off-by: Greg Kroah-Hartman

usb: Add USB 3.1 Precision time measurement capability descriptor support

2016-02-15T01:03:23+00:00

USB 3.1 devices that support precision time measurement have an
additional PTM cabaility descriptor as part of the full BOS descriptor

Look for this descriptor while parsing the BOS descriptor, and store it in
struct usb_hub_bos if it exists.

Signed-off-by: Mathias Nyman 
Signed-off-by: Greg Kroah-Hartman

usb: Parse the new USB 3.1 SuperSpeedPlus Isoc endpoint companion descriptor

2016-02-15T01:03:23+00:00

USB 3.1 devices can return a new SuperSpeedPlus isoc endpoint companion
descriptor for a isochronous endpoint that requires more than 48K bytes
per Service Interval.

The new descriptor immediately follows the old USB 3.0 SuperSpeed Endpoint
Companion and will provide a new BytesPerInterval value.

It is parsed and stored in struct usb_host_endpoint with the other endpoint
related descriptors, and should be used by USB3.1 capable hosts to reserve
bus time in the schedule.

Signed-off-by: Mathias Nyman 
Signed-off-by: Greg Kroah-Hartman

usb: sysfs: make locking interruptible

2016-02-03T21:29:12+00:00

232275a USB: fix substandard locking for the sysfs files
introduced needed locking into sysfs operations on USB devices
It, however, uses uninterruptible sleep and if the error
handling is on extreme cases of sleep lengths of 10s of seconds
are possible. Unless we are removing the device we should use
interruptible sleep.

Signed-off-by: Oliver Neukum 
Signed-off-by: Greg Kroah-Hartman

usb: core: switch bus numbering to using idr

2016-02-03T21:26:30+00:00

USB bus numbering is based on directly dealing with bitmaps and
defines a separate list of busses.
This can be simplified and unified by using existing idr functionality.

Signed-off-by: Heiner Kallweit 
Signed-off-by: Greg Kroah-Hartman

usb: core: lpm: remove usb3_lpm_enabled in usb_device

2015-12-01T22:58:18+00:00

Commit 8306095fd2c1 ("USB: Disable USB 3.0 LPM in critical sections.")
adds usb3_lpm_enabled member to struct usb_device. There is no reference
to this member now. Hence, it could be removed.

Signed-off-by: Lu Baolu 
Signed-off-by: Greg Kroah-Hartman