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path: root/drivers/usb/core/generic.c
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2009-09-23USB: add API for userspace drivers to "claim" portsAlan Stern
This patch (as1258) implements a feature that users have been asking for: It gives programs the ability to "claim" a port on a hub, via a new usbfs ioctl. A device plugged into a "claimed" port will not be touched by the kernel beyond the immediate necessities of initialization and enumeration. In particular, when a device is plugged into a "claimed" port, the kernel will not select and install a configuration. And when a config is installed by usbfs or sysfs, the kernel will not probe any drivers for any of the interfaces. (However the kernel will fetch various string descriptors during enumeration. One could argue that this isn't really necessary, but the strings are exported in sysfs.) The patch does not guarantee exclusive access to these devices; it is still possible for more than one program to open the device file concurrently. Programs are responsible for coordinating access among themselves. A demonstration program showing how to use the new interface can be found in an attachment to http://marc.info/?l=linux-usb&m=124345857431452&w=2 The patch also makes a small simplification to the hub driver, replacing a bunch of more-or-less useless variants of "out of memory" with a single message. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-01-07USB: Enhance usage of pm_message_tAlan Stern
This patch (as1177) modifies the USB core suspend and resume routines. The resume functions now will take a pm_message_t argument, so they will know what sort of resume is occurring. The new argument is also passed to the port suspend/resume and bus suspend/resume routines (although they don't use it for anything but debugging). In addition, special pm_message_t values are used for user-initiated, device-initiated (i.e., remote wakeup), and automatic suspend/resume. By testing these values, drivers can tell whether or not a particular suspend was an autosuspend. Unfortunately, they can't do the same for resumes -- not until the pm_message_t argument is also passed to the drivers' resume methods. That will require a bigger change. IMO, the whole Power Management framework should have been set up this way in the first place. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-05-29USB: fix possible deadlock involving sysfs attributesAlan Stern
There is a potential deadlock when the usb_generic driver is unbound from a device. The problem is that generic_disconnect() is called with the device lock held, and it removes a bunch of device attributes from sysfs. If a user task happens to be running an attribute method at the time, the removal will block until the method returns. But at least one of the attribute methods (the store routine for power/level) needs to acquire the device lock! This patch (as1093) eliminates the deadlock by moving the calls to create and remove the sysfs attributes from the usb_generic driver into usb_new_device() and usb_disconnect(), where they can be invoked without holding the device lock. Besides, the other sysfs attributes are created when the device is registered and removed when the device is unregistered. So it seems only fitting for the extra attributes to be created and removed at the same time. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12USB: move decision to ignore FREEZE eventsAlan Stern
This patch (as987) changes the way FREEZE and PRETHAW suspend events are handled in usbcore. The decision about whether or not to ignore them for non-root devices is pushed down into the USB-device driver, instead of being made in the core code. This is appropriate, since devices exported to a virtualized guest or over a network may indeed need to handle these types of suspend, even though normal devices don't. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12USB: rename choose_configurationGreg Kroah-Hartman
As it is global, give it a usb specific name in the global namespace. Cc: Inaky Perez-Gonzalez <inaky@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12usb: introduce usb_authorize/deauthorize()Inaky Perez-Gonzalez
These USB API functions will do the full authorization/deauthorization to be used for a device. When authorized we effectively allow a configuration to be set. Reverse that when deauthorized. Effectively this means that we have to clean all the configuration descriptors on deauthorize and reload them when we authorized. We could do without throwing them out for wired devices, but for wireless, we can read them only after authenticating, and thus, when authorizing an authenticated device we would need to read them. So to simplify, always release them on deauthorize(), re-read them on authorize(). Also fix leak reported by Ragner Magalhaes; in usb_deauthorize_device(), bNumConfigurations was being set to zero before the for loop, and thus the different raw descriptors where never being freed. Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12usb: usb_generic_probe() obeys authorizationInaky Perez-Gonzalez
If called and the device is not authorized to be used, then we won't choose a configuration (as they are not a concept that exists for an unauthorized device). However, the device is added to the system. Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-12USB: unify reset_resume and normal resumeAlan Stern
This patch (as919) unifies the code paths used for normal resume and for reset-resume. Earlier I had failed to note a section in the USB spec which requires the host to resume a suspended port before resetting it if the attached device is enabled for remote wakeup. Since the port has to be resumed anyway, we might as well reuse the existing code. The main changes are: usb_reset_suspended_device() is eliminated. usb_root_hub_lost_power() is moved down next to the hub_reset_resume() routine, to which it is logically related. finish_port_resume() does a port reset() if the device's reset_resume flag is set. usb_port_resume() doesn't check whether the port is initially enabled if this is a USB-Persist sort of resume. Code to perform the port reset is added to the resume pathway for the non-CONFIG_USB_SUSPEND case. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-12USB: separate root and non-root suspend/resumeAlan Stern
This patch (as916) completes the separation of code paths for suspend and resume of root hubs as opposed to non-root devices. Root hubs will be power-managed through their bus_suspend and bus_resume methods, whereas normal devices will use usb_port_suspend() and usb_port_resume(). Changes to the hcd_bus_{suspend,resume} routines mostly represent motion of code that was already present elsewhere. They include: Adding debugging log messages, Setting the device state appropriately, and Adding a resume recovery time delay. Changes to the port-suspend and port-resume routines in hub.c include: Removal of checks for root devices (since they will never be triggered), and Removal of checks for NULL or invalid device pointers (these were left over from earlier kernel versions and aren't needed at all). Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-12USB: add USB-Persist facilityAlan Stern
This patch (as886) adds the controversial USB-persist facility, allowing USB devices to persist across a power loss during system suspend. The facility is controlled by a new Kconfig option (with appropriate warnings about the potential dangers); when the option is off the behavior will remain the same as it is now. But when the option is on, people will be able to use suspend-to-disk and keep their USB filesystems intact -- something particularly valuable for small machines where the root filesystem is on a USB device! Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-12USB: move bus_suspend and bus_resume method callsAlan Stern
This patch (as885) moves the root-hub bus_suspend() and bus_resume() method calls from the hub driver's suspend and resume methods into the usb_generic driver methods, where they make just as much sense. Their old locations were not fully correct. For example, in a kernel compiled without CONFIG_USB_SUSPEND, if one were to do: echo -n 1-0:1.0 >/sys/bus/usb/drivers/hub/unbind to unbind the hub driver from a root hub, there would then be no way to suspend that root hub. Attempts to put the system to sleep would fail; the USB controller driver would refuse to suspend because the root hub was still active. The patch also makes a very slight change in the way devices with no driver are handled during suspend. Rather than doing a standard USB port-suspend directly, now the suspend routine in usb_generic is called. In practice this should never affect anyone. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-12USB: Implement PM FREEZE and PRETHAWAlan Stern
This patch (as884) finally implements the time-saving semantics possible with the Power Management FREEZE and PRETHAW events. Their proper handling requires only that devices be quiesced, with interrupts and DMA turned off; non-root USB devices don't actually need to be put in a suspended state. The patch checks and avoids doing the suspend call when possible. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-16USB: unconfigure devices which have config 0Alan Stern
Some USB devices do have a configuration 0, in contravention of the USB spec. Normally 0 is supposed to indicate that a device is unconfigured. While we can't change what the device is doing, we can change usbcore. This patch (as852) allows usb_set_configuration() to accept a config value of -1 as indicating that the device should be unconfigured. The request actually sent to the device will still contain 0 as the value. But even if the device does have a configuration 0, dev->actconfig will be set to NULL and dev->state will be set to USB_STATE_ADDRESS. Without some sort of special-case handling like this, there is no way to unconfigure these non-compliant devices. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-07rndis_host learns ActiveSync basicsOle Andre Vadla Ravnas
Windows Mobile 5 based devices described as supporting "ActiveSync": - Speak RNDIS but lack the CDC and union descriptors. This patch updates the cdc ethernet code to fake ACM descriptors we need. - Require RNDIS_MSG_QUERY messages to include a buffer of the size the response should generate. This patch updates the rndis host code to pass this will-be-ignored data. The resulting RNDIS host code has been reported to work with several WM5 based devices. (Note that a fancier patch is available at synce.sf.net.) Some bugfixes, affecting not just ActiveSync: (a) when cleaning up after RNDS init fails, scrub the second interface just like cdc_ether does, so disconnect won't oops. (b) handle peripherals that use the pad-to-end-of-packet option; some devices can't talk to us if that option doesn't work. (c) when choosing configurations, don't forget about an RNDIS config just because the RNDIS driver is dynamically linked. Cleanup, streamlining, bugfixes, Kconfig, and matching hub driver update. Also for paranoia's sake, refuse to talk to something that looks like a real modem instead of RNDIS. Signed-off-by: Ole Andre Vadla Ravnaas <oleavr@gmail.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-10-04Remove all inclusions of <linux/config.h>Dave Jones
kbuild explicitly includes this at build time. Signed-off-by: Dave Jones <davej@redhat.com>
2006-09-27usbcore: non-hub-specific uses of autosuspendAlan Stern
This patch (as741) makes the non-hub parts of usbcore actually use the autosuspend facilities added by an earlier patch. Devices opened through usbfs are autoresumed and then autosuspended upon close. Likewise for usb-skeleton. Devices are autoresumed for usb_set_configuration. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-27usbcore: fix up device and power state testsAlan Stern
This patch (as734) rationalizes the various tests of device state and power states. There are duplications and mistaken tests in several places. Perhaps the most interesting challenge is where the hub driver tests to see that all the child devices are suspended before allowing itself to be suspended. When CONFIG_USB_SUSPEND is set the test is straightforward, since we expect that the children _will_ be suspended. But when CONFIG_USB_SUSPEND isn't set, it's not so clear what should be done. The code compromises by checking the child's power.power_state.event field. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-27usbcore: resume device resume recursionAlan Stern
This patch (as717b) removes the existing recursion in hub resume code: Resuming a hub will no longer automatically resume the devices attached to the hub. At the same time, it adds one level of recursion: Suspending a USB device will automatically suspend all the device's interfaces. Failure at an intermediate stage will cause all the already-suspended interfaces to be resumed. Attempts to suspend or resume an interface by itself will do nothing, although they won't return an error. Thus the regular system-suspend and system-resume procedures should continue to work as before; only runtime PM will be affected. The patch also removes the code that tests state of the interfaces before suspending a device. It's no longer needed, since everything gets suspended together. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-27usbcore: make usb_generic a usb_device_driverAlan Stern
This patch (as714b) makes usb_generic into a usb_device_driver capable of being probed and unbound, just like other drivers. A fair amount of the work that used to get done during discovery or removal of a USB device have been moved to the probe and disconnect methods of usb_generic: creating the sysfs attributes and selecting an initial configuration. However the normal behavior should continue to be the same as before. We will now have the possibility of creating other USB device drivers, They will assist with exporting devices to remote systems (USB-over-TCPIP) or to paravirtual guest operating systems. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-27usbcore: add usb_device_driver definitionAlan Stern
This patch (as732) adds a usb_device_driver structure, for representing drivers that manage an entire USB device as opposed to just an interface. Support routines like usb_register_device_driver, usb_deregister_device_driver, usb_probe_device, and usb_unbind_device are also added. Unlike an earlier version of this patch, the new code is type-safe. To accomplish this, the existing struct driver embedded in struct usb_driver had to be wrapped in an intermediate wrapper. This enables the core to tell at runtime whether a particular struct driver belongs to a device driver or to an interface driver. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-27usbcore: move code among source filesAlan Stern
This revised patch (as713b) moves a few routines among source files in usbcore. Some driver-related code in usb.c (claiming interfaces and matching IDs) is moved to driver.c, where it belongs. Also the usb_generic stuff in driver.c is moved to a new source file: generic.c. (That's the reason for revising the patch.) Although not very big now, it will get bigger in a later patch. None of the code has been changed; it has only been re-arranged. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>