kernel.git/drivers/usb/core/driver.c, branch linux-2.6.27.y

USB: don't rebind drivers after failed resume or reset

2008-10-25T21:32:38Z

commit 6c6409459a18a825ce12ecb003d5686af61f7a2f upstream This patch (as1152) may help prevent some problems associated with the new policy of unbinding drivers that don't support suspend/resume or pre_reset/post_reset. If for any reason the resume or reset fails, and the device is logically disconnected, there's no point in trying to rebind the driver. So the patch checks for success before carrying out the unbind/rebind. There was a report from one user that this fixed a problem he was experiencing, but the details never became fully clear. In any case, adding these tests can't hurt. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman

USB: Don't rebind before "complete" callback

2008-08-21T17:26:37Z

This patch (as1130) fixes an incompatibility between the new PM infrastructure and USB power management. We are not allowed to call drivers' probe routines during a system sleep transition between the "prepare" and "complete" callbacks, but that's exactly what we do when a driver doesn't have full suspend/resume support. Such drivers are unbound during the "suspend" call and reprobed during the "resume" call. The patch causes the reprobe step to be skipped if the "complete" callback hasn't been issued yet, i.e., if the interface's dev.power.status field is not equal to DPM_ON. Thus during the "resume" callback nothing bad will happen, and during the final "complete" callback the reprobing will occur as desired. This fixes the problem reported in Bugzilla #11263. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman

USB: Add new PM callback methods for USB

2008-08-21T17:26:37Z

This patch (as1129) adds support for the new PM callbacks to usbcore. The new callbacks merely invoke the same old USB power management routines as the old ones did. A minor improvement is that the callbacks are present only in the "USB-device" device_type structure, rather than in the bus_type structure. This way they will be invoked only for USB devices, not for USB interfaces. The core USB PM routines automatically handle suspending and resuming interfaces along with their devices. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman

USB: Defer Set-Interface for suspended devices

2008-08-21T17:26:36Z

This patch (as1128) fixes one of the problems related to the new PM infrastructure. We are not allowed to register new child devices during the middle of a system sleep transition, but unbinding a USB driver causes the core to automatically install altsetting 0 and thereby create new endpoint pseudo-devices. The patch fixes this problem (and the related problem that installing altsetting 0 will fail if the device is suspended) by deferring the Set-Interface call until some later time when it is legal and can succeed. Possible later times are: when a new driver is being probed for the interface, and when the interface is being resumed. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman

USB: Add udev argument to interface suspend/resume functions

2008-08-21T17:26:36Z

This patch (as1127) makes a minor change to the prototypes of the usb_suspend_interface() and usb_resume_interface() routines. Now the usb_device structure is passed as an argument, instead of being computed on-the-fly from the usb_interface argument. It makes the code look simpler, even if it really isn't much different from before. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman

USB: fix compiler warning fix

2008-08-14T00:32:56Z

This patch (as1123b) fixes a compiler warning: do_unbind_rebind() is defined but not used if CONFIG_PM=n. Problem originally found and initial patch submitted by Alexander Beregalov . Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman

usb/core/driver: fix warning

2008-08-14T00:32:49Z

usb/core/driver: fix warning: drivers/usb/core/driver.c:834: warning: 'do_unbind_rebind' defined but not used Signed-off-by: Alexander Beregalov Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman

USB: Force unbinding of drivers lacking reset_resume or other methods

2008-07-21T22:16:40Z

This patch (as1024) takes care of a FIXME issue: Drivers that don't have the necessary suspend, resume, reset_resume, pre_reset, or post_reset methods will be unbound and their interface reprobed when one of the unsupported events occurs. This is made slightly more difficult by the fact that bind operations won't work during a system sleep transition. So instead the code has to defer the operation until the transition ends. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman

USB: implement "soft" unbinding

2008-07-21T22:15:54Z

This patch (as1091) changes the way usbcore handles interface unbinding. If the interface's driver supports "soft" unbinding (a new flag in the driver structure) then in-flight URBs are not cancelled and endpoints are not disabled. Instead the driver is allowed to continue communicating with the device (although of course it should stop before its disconnect routine returns). The purpose of this change is to allow drivers to do a clean shutdown when they get unbound from a device that is still plugged in. Killing all the URBs and disabling the endpoints before calling the driver's disconnect method doesn't give the driver any control over what happens, and it can leave devices in indeterminate states. For example, when usb-storage unbinds it doesn't want to stop while in the middle of transmitting a SCSI command. The soft_unbind flag is added because in the past, a number of drivers have experienced problems related to ongoing I/O after their disconnect routine returned. Hence "soft" unbinding is made available only to drivers that claim to support it. The patch also replaces "interface_to_usbdev(intf)" with "udev" in a couple of places, a minor simplification. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman

USB: try to salvage lost power sessions

2008-07-21T22:15:51Z

This patch (as1073) adds to khubd a way to recover from power-session interruption caused by transient connect-change or enable-change events. After the debouncing period, khubd attempts to do a USB-Persist-style reset or reset-resume. If it works, the connection will remain unscathed. The upshot is that we will be more immune to noise caused by EMI. The grace period is on the order of 100 ms, so this won't permit recovery from the "accidentally knocked the USB cable out of its socket" type of event, but it's a start. As an added bonus, if a device was suspended when the system goes to sleep then we no longer need to check for power-session interruptions when the system wakes up. Khubd will naturally see the status change while processing the device's parent hub and will do the right thing. The remote_wakeup() routine is changed; now it expects the caller to acquire the device lock rather than acquiring the lock itself. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman