USB_RESET_DEVICE(9) USB Core APIs USB_RESET_DEVICE(9)NAME
usb_reset_device - warn interface drivers and perform a USB port reset
SYNOPSIS
int usb_reset_device(struct usb_device * udev);
ARGUMENTS
udev
device to reset (not in SUSPENDED or NOTATTACHED state)
DESCRIPTION
Warns all drivers bound to registered interfaces (using their pre_reset method), performs the port reset, and then lets the drivers know
that the reset is over (using their post_reset method).
Return value is the same as for usb_reset_and_verify_device.
The caller must own the device lock. For example, it's safe to use this from a driver probe routine after downloading new firmware. For
calls that might not occur during probe, drivers should lock the device using usb_lock_device_for_reset.
If an interface is currently being probed or disconnected, we assume its driver knows how to handle resets. For all other interfaces, if
the driver doesn't have pre_reset and post_reset methods then we attempt to unbind it and rebind afterward.
COPYRIGHT Kernel Hackers Manual 2.6. July 2010 USB_RESET_DEVICE(9)
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STRUCT USB_DRIVER(9) Host-Side Data Types and Macro STRUCT USB_DRIVER(9)NAME
struct_usb_driver - identifies USB interface driver to usbcore
SYNOPSIS
struct usb_driver {
const char * name;
int (* probe) (struct usb_interface *intf,const struct usb_device_id *id);
void (* disconnect) (struct usb_interface *intf);
int (* unlocked_ioctl) (struct usb_interface *intf, unsigned int code,void *buf);
int (* suspend) (struct usb_interface *intf, pm_message_t message);
int (* resume) (struct usb_interface *intf);
int (* reset_resume) (struct usb_interface *intf);
int (* pre_reset) (struct usb_interface *intf);
int (* post_reset) (struct usb_interface *intf);
const struct usb_device_id * id_table;
struct usb_dynids dynids;
struct usbdrv_wrap drvwrap;
unsigned int no_dynamic_id:1;
unsigned int supports_autosuspend:1;
unsigned int disable_hub_initiated_lpm:1;
unsigned int soft_unbind:1;
};
MEMBERS
name
The driver name should be unique among USB drivers, and should normally be the same as the module name.
probe
Called to see if the driver is willing to manage a particular interface on a device. If it is, probe returns zero and uses
usb_set_intfdata to associate driver-specific data with the interface. It may also use usb_set_interface to specify the appropriate
altsetting. If unwilling to manage the interface, return -ENODEV, if genuine IO errors occurred, an appropriate negative errno value.
disconnect
Called when the interface is no longer accessible, usually because its device has been (or is being) disconnected or the driver module
is being unloaded.
unlocked_ioctl
Used for drivers that want to talk to userspace through the "usbfs" filesystem. This lets devices provide ways to expose information to
user space regardless of where they do (or don't) show up otherwise in the filesystem.
suspend
Called when the device is going to be suspended by the system either from system sleep or runtime suspend context. The return value
will be ignored in system sleep context, so do NOT try to continue using the device if suspend fails in this case. Instead, let the
resume or reset-resume routine recover from the failure.
resume
Called when the device is being resumed by the system.
reset_resume
Called when the suspended device has been reset instead of being resumed.
pre_reset
Called by usb_reset_device when the device is about to be reset. This routine must not return until the driver has no active URBs for
the device, and no more URBs may be submitted until the post_reset method is called.
post_reset
Called by usb_reset_device after the device has been reset
id_table
USB drivers use ID table to support hotplugging. Export this with MODULE_DEVICE_TABLE(usb,...). This must be set or your driver's probe
function will never get called.
dynids
used internally to hold the list of dynamically added device ids for this driver.
drvwrap
Driver-model core structure wrapper.
no_dynamic_id
if set to 1, the USB core will not allow dynamic ids to be added to this driver by preventing the sysfs file from being created.
supports_autosuspend
if set to 0, the USB core will not allow autosuspend for interfaces bound to this driver.
disable_hub_initiated_lpm
if set to 0, the USB core will not allow hubs to initiate lower power link state transitions when an idle timeout occurs.
Device-initiated USB 3.0 link PM will still be allowed.
soft_unbind
if set to 1, the USB core will not kill URBs and disable endpoints before calling the driver's disconnect method.
DESCRIPTION
USB interface drivers must provide a name, probe and disconnect methods, and an id_table. Other driver fields are optional.
The id_table is used in hotplugging. It holds a set of descriptors, and specialized data may be associated with each entry. That table is
used by both user and kernel mode hotplugging support.
The probe and disconnect methods are called in a context where they can sleep, but they should avoid abusing the privilege. Most work to
connect to a device should be done when the device is opened, and undone at the last close. The disconnect code needs to address
concurrency issues with respect to open and close methods, as well as forcing all pending I/O requests to complete (by unlinking them as
necessary, and blocking until the unlinks complete).
COPYRIGHT Kernel Hackers Manual 3.10 June 2014 STRUCT USB_DRIVER(9)