linux/drivers/usb/core, branch v4.7

USB: don't free bandwidth_mutex too early

2016-06-27T15:39:39Z

The USB core contains a bug that can show up when a USB-3 host controller is removed. If the primary (USB-2) hcd structure is released before the shared (USB-3) hcd, the core will try to do a double-free of the common bandwidth_mutex. The problem was described in graphical form by Chung-Geol Kim, who first reported it: ================================================= At *remove USB(3.0) Storage sequence <1> --> <5> ((Problem Case)) ================================================= VOLD ------------------------------------|------------ (uevent) ________|_________ |<1> | |dwc3_otg_sm_work | |usb_put_hcd | |peer_hcd(kref=2)| |__________________| ________|_________ |<2> | |New USB BUS #2 | | | |peer_hcd(kref=1) | | | --(Link)-bandXX_mutex| | |__________________| | ___________________ | |<3> | | |dwc3_otg_sm_work | | |usb_put_hcd | | |primary_hcd(kref=1)| | |___________________| | _________|_________ | |<4> | | |New USB BUS #1 | | |hcd_release | | |primary_hcd(kref=0)| | | | | |bandXX_mutex(free) |<- |___________________| (( VOLD )) ______|___________ |<5> | | SCSI | |usb_put_hcd | |peer_hcd(kref=0) | |*hcd_release | |bandXX_mutex(free*)|<- double free |__________________| ================================================= This happens because hcd_release() frees the bandwidth_mutex whenever it sees a primary hcd being released (which is not a very good idea in any case), but in the course of releasing the primary hcd, it changes the pointers in the shared hcd in such a way that the shared hcd will appear to be primary when it gets released. This patch fixes the problem by changing hcd_release() so that it deallocates the bandwidth_mutex only when the _last_ hcd structure referencing it is released. The patch also removes an unnecessary test, so that when an hcd is released, both the shared_hcd and primary_hcd pointers in the hcd's peer will be cleared. Signed-off-by: Alan Stern Reported-by: Chung-Geol Kim Tested-by: Chung-Geol Kim CC: Signed-off-by: Greg Kroah-Hartman

usb: quirks: Add no-lpm quirk for Acer C120 LED Projector

2016-06-01T21:56:24Z

The Acer C120 LED Projector is a USB-3 connected pico projector which takes both its power and video data from USB-3. In combination with some hubs this device does not play well with lpm, so disable lpm for it. Signed-off-by: Hans de Goede Cc: stable Signed-off-by: Greg Kroah-Hartman

usb: quirks: Fix sorting

2016-06-01T21:56:24Z

Properly sort all the entries by vendor id. Signed-off-by: Hans de Goede Cc: stable Signed-off-by: Greg Kroah-Hartman

Merge 4.6-rc7 into usb-next

2016-05-09T07:29:13Z

We want the USB fixes in here to resolve merge issues and make it easier for testing. Signed-off-by: Greg Kroah-Hartman

USB: usbfs: fix potential infoleak in devio

2016-05-03T21:32:07Z

The stack object “ci” has a total size of 8 bytes. Its last 3 bytes are padding bytes which are not initialized and leaked to userland via “copy_to_user”. Signed-off-by: Kangjie Lu Signed-off-by: Greg Kroah-Hartman

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

2016-05-03T21:32:07Z

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

Revert "USB / PM: Allow USB devices to remain runtime-suspended when sleeping"

2016-05-02T15:44:31Z

This reverts commit e3345db85068ddb937fc0ba40dfc39c293dad977, which broke system resume for a large class of devices. Devices that after having been reset during resume need to be rebound due to a missing reset_resume callback, are now left in a suspended state. This specifically broke resume of common USB-serial devices, which are now unusable after system suspend (until disconnected and reconnected) when USB persist is enabled. During resume, usb_resume_interface will set the needs_binding flag for such interfaces, but unlike system resume, run-time resume does not honour it. Cc: stable # 4.5 Signed-off-by: Johan Hovold Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman

usb: core: move root hub's device node assignment after it is added to bus

2016-04-28T19:57:49Z

When the root hub device is added to the bus, it tries to get pins information from pinctrl (see pinctrl_bind_pins, at really_probe), if the pin information is described at DT, it will show below error since the root hub's device node is the same with controller's, but controller's pin has already been requested when it is added to platform bus. imx6q-pinctrl 20e0000.iomuxc: pin MX6Q_PAD_GPIO_1 already requested by 2184000.usb; cannot claim for usb1 imx6q-pinctrl 20e0000.iomuxc: pin-137 (usb1) status -22 imx6q-pinctrl 20e0000.iomuxc: could not request pin 137 (MX6Q_PAD_GPIO_1) from group usbotggrp-3 on device 20e0000.iomuxc usb usb1: Error applying setting, reverse things back To fix this issue, we move the root hub's device node assignment (equals to contrller's) after device is added to bus, we only need to know root hub's device node information after the device under root hub is created, so this movement will not affect current function. Signed-off-by: Peter Chen Reported-by: Lars Steubesand Signed-off-by: Greg Kroah-Hartman

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

2016-04-28T19:40:46Z

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: devio: declare usbdev_vm_ops as static

2016-04-28T19:35:36Z

usbdev_vm_ops is used in devio.c only, so declare it as static Signed-off-by: Michele Curti Signed-off-by: Greg Kroah-Hartman