linux/drivers/usb/core, branch v3.16

usb: Check if port status is equal to RxDetect

2014-07-18T00:14:01Z

When using USB 3.0 pen drive with the [AMD] FCH USB XHCI Controller [1022:7814], the second hotplugging will experience the USB 3.0 pen drive is recognized as high-speed device. After bisecting the kernel, I found the commit number 41e7e056cdc662f704fa9262e5c6e213b4ab45dd (USB: Allow USB 3.0 ports to be disabled.) causes the bug. After doing some experiments, the bug can be fixed by avoiding executing the function hub_usb3_port_disable(). Because the port status with [AMD] FCH USB XHCI Controlleris [1022:7814] is already in RxDetect (I tried printing out the port status before setting to Disabled state), it's reasonable to check the port status before really executing hub_usb3_port_disable(). Fixes: 41e7e056cdc6 (USB: Allow USB 3.0 ports to be disabled.) Signed-off-by: Gavin Guo Acked-by: Alan Stern Cc: Signed-off-by: Greg Kroah-Hartman

usb: fix hub-port pm_runtime_enable() vs runtime pm transitions

2014-06-18T00:04:39Z

Commit 9262c19d14c4 "usb: disable port power control if not supported in wHubCharacteristics" gated enabling runtime pm for usb_port devices on whether the parent hub supports power control, which causes a regression. The port must still be allowed to carry out runtime pm callbacks and receive a -EAGAIN or -EBUSY result. Otherwise the usb_port device will transition to the pm error state and trigger the same for the child usb_device. Prior to the offending commit usb_hub_create_port_device() arranged for runtime pm to be disabled is dev_pm_qos_expose_flags() failed. Instead, force the default state of PM_QOS_FLAG_NO_POWER_OFF flag to be set prior to enabling runtime pm. If that policy can not be set then fail registration. Report: http://marc.info/?l=linux-usb&m=140290586301336&w=2 Fixes: 9262c19d14c4 ("usb: disable port power control if not supported in wHubCharacteristics") Reported-by: Bjørn Mork Reported-by: Alan Stern Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman

usb: quiet peer failure warning, disable poweroff

2014-06-18T00:04:39Z

In the case where platform firmware has specified conflicting values for port locations it is confusing and otherwise not helpful to throw a backtrace. Instead, include enough information to determine that firmware has done something wrong and globally disable port poweroff. Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman

usb: improve "not suspended yet" message in hub_suspend()

2014-06-17T23:44:57Z

Reading through a recent bug report [1], Alan notes: "Dan, the warning message in hub_suspend() should mention that the child device isn't suspended yet." ...update the warning from: "usb usb3-port4: not suspended yet" ...to: "usb usb3-port4: device 3-4: not suspended yet" [1]: http://marc.info/?l=linux-usb&m=140290586301336&w=2 Reported-by: Alan Stern Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman

usb: fix ->update_hub_device() vs hdev->maxchild

2014-06-17T23:44:57Z

Commit d8521afe3586 "usb: assign default peer ports for root hubs" delayed marking a hub valid (set hdev->maxchild) until it had been fully configured and to enable the publishing of valid hubs to be serialized by usb_port_peer_mutex. However, xhci_update_hub_device() in some cases depends on hdev->maxchild already being set. Do the minimal fix and move it after the setting of hdev->maxchild. Cc: Mathias Nyman Reported-by: Valdis Kletnieks Tested-by: Valdis Kletnieks Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman

Merge branch 'next' (accumulated 3.16 merge window patches) into master

2014-06-08T18:31:16Z

Now that 3.15 is released, this merges the 'next' branch into 'master', bringing us to the normal situation where my 'master' branch is the merge window. * accumulated work in next: (6809 commits) ufs: sb mutex merge + mutex_destroy powerpc: update comments for generic idle conversion cris: update comments for generic idle conversion idle: remove cpu_idle() forward declarations nbd: zero from and len fields in NBD_CMD_DISCONNECT. mm: convert some level-less printks to pr_* MAINTAINERS: adi-buildroot-devel is moderated MAINTAINERS: add linux-api for review of API/ABI changes mm/kmemleak-test.c: use pr_fmt for logging fs/dlm/debug_fs.c: replace seq_printf by seq_puts fs/dlm/lockspace.c: convert simple_str to kstr fs/dlm/config.c: convert simple_str to kstr mm: mark remap_file_pages() syscall as deprecated mm: memcontrol: remove unnecessary memcg argument from soft limit functions mm: memcontrol: clean up memcg zoneinfo lookup mm/memblock.c: call kmemleak directly from memblock_(alloc|free) mm/mempool.c: update the kmemleak stack trace for mempool allocations lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations mm: introduce kmemleak_update_trace() mm/kmemleak.c: use %u to print ->checksum ...

usb: hub_handle_remote_wakeup() only exists for CONFIG_PM=y

2014-06-02T22:16:33Z

Signed-off-by: Stephen Rothwell Acked-by: Dan Williams Signed-off-by: Greg Kroah-Hartman

usb: resume child device when port is powered on

2014-05-28T00:25:37Z

Unconditionally wake up the child device when the power session is recovered. This addresses the following scenarios: 1/ The device may need a reset on power-session loss, without this change port power-on recovery exposes khubd to scenarios that usb_port_resume() is set to handle. Prior to port power control the only time a power session would be lost is during dpm_suspend of the hub. In that scenario usb_port_resume() is guaranteed to be called prior to khubd running for that port. With this change we wakeup the child device as soon as possible (prior to khubd running again for this port). Although khubd has facilities to wake a child device it will only do so if the portstatus / portchange indicates a suspend state. In the case of port power control we are not coming from a hub-port-suspend state. This implementation simply uses pm_request_resume() to wake the device and relies on the port_dev->status_lock to prevent any collisions between khubd and usb_port_resume(). 2/ This mechanism rate limits port power toggling. The minimum port power on/off period is now gated by the child device suspend/resume latency. Empirically this mitigates devices downgrading their connection on perceived instability of the host connection. This ratelimiting is really only relevant to port power control testing, but it is a nice side effect of closing the above race. Namely, the race of khubd for the given port running while a usb_port_resume() event is pending. 3/ Going forward we are finding that power-session recovery requires warm-resets (http://marc.info/?t=138659232900003&r=1&w=2). This mechanism allows for warm-resets to be requested at the same point in the resume path for hub dpm_suspend power session losses, or port rpm_suspend power session losses. 4/ If the device *was* disconnected the only time we'll know for sure is after a failed resume, so it's necessary for usb_port_runtime_resume() to expedite a usb_port_resume() to clean up the removed device. The reasoning for this is "least surprise" for the user. Turning on a port means that hotplug detection is again enabled for the port, it is surprising that devices that were removed while the port was off are not disconnected until they are attempted to be used. As a user "why would I try to use a device I removed from the system?" 1, 2, and 4 are not a problem in the system dpm_resume() case because, although the power-session is lost, khubd is frozen until after device resume. For the rpm_resume() case pm_request_resume() is used to request re-validation of the device, and if it happens to collide with a khubd run we rely on the port_dev->status_lock to synchronize those operations. Besides testing, the primary scenario where this mechanism is expected to be triggered is when the user changes the port power policy (control/pm_qos_no_poweroff, or power/control). Each time power is enabled want to revalidate the child device, where the revalidation is handled by usb_port_resume(). Given that this arranges for port_dev->child to be de-referenced in usb_port_runtime_resume() we need to make sure not to collide with usb_disconnect() that frees the usb_device. To this end we hold the port active with the "child_usage" reference across the disconnect event. Subsequently, the need to access hub->child_usage_bits lead to the creation of hub_disconnect_children() to remove any ambiguity of which "hub" is being acted on in usb_disconnect() (prompted-by sharp eyes from Alan). Cc: Rafael J. Wysocki Acked-by: Alan Stern Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman

usb: hub_handle_remote_wakeup() depends on CONFIG_PM_RUNTIME=y

2014-05-27T23:51:51Z

Per Alan: "You mean from within hub_handle_remote_wakeup()? That routine will never get called if CONFIG_PM_RUNTIME isn't enabled, because khubd never sees wakeup requests if they arise during system suspend. In fact, that routine ought to go inside the "#ifdef CONFIG_PM_RUNTIME" portion of hub.c, along with the other suspend/resume code." Suggested-by: Alan Stern Acked-by: Alan Stern Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman

usb: introduce port status lock

2014-05-27T23:51:50Z

In general we do not want khubd to act on port status changes that are the result of in progress resets or USB runtime PM operations. Specifically port power control testing has been able to trigger an unintended disconnect in hub_port_connect_change(), paraphrasing: if ((portstatus & USB_PORT_STAT_CONNECTION) && udev && udev->state != USB_STATE_NOTATTACHED) { if (portstatus & USB_PORT_STAT_ENABLE) { /* Nothing to do */ } else if (udev->state == USB_STATE_SUSPENDED && udev->persist_enabled) { ... } else { /* Don't resuscitate */; } } ...by falling to the "Don't resuscitate" path or missing USB_PORT_STAT_CONNECTION because usb_port_resume() was in the middle of modifying the port status. So, we want a new lock to hold off khubd for a given port while the child device is being suspended, resumed, or reset. The lock ordering rules are now usb_lock_device() => usb_lock_port(). This is mandated by the device core which may hold the device_lock on the usb_device before invoking usb_port_{suspend|resume} which in turn take the status_lock on the usb_port. We attempt to hold the status_lock for the duration of a port_event() run, and drop/re-acquire it when needing to take the device_lock. The lock is also dropped/re-acquired during hub_port_reconnect(). This patch also deletes hub->busy_bits as all use cases are now covered by port PM runtime synchronization or the port->status_lock and it pushes down usb_device_lock() into usb_remote_wakeup(). Acked-by: Alan Stern Signed-off-by: Dan Williams Signed-off-by: Greg Kroah-Hartman