user/sven/linux.git/drivers/usb/core/sysfs.c, branch v4.4.94

usb: core: lpm: fix usb3_hardware_lpm sysfs node

2016-01-31T19:28:58Z

commit bf5ce5bf3cc7136fd7fe5e8999a580bc93a9c8f6 upstream. Commit 655fe4effe0f ("usbcore: add sysfs support to xHCI usb3 hardware LPM") introduced usb3_hardware_lpm sysfs node. This doesn't show the correct status of USB3 U1 and U2 LPM status. This patch fixes this by replacing usb3_hardware_lpm with two nodes, usb3_hardware_lpm_u1 (for U1) and usb3_hardware_lpm_u2 (for U2), and recording the U1/U2 LPM status in right places. This patch should be back-ported to kernels as old as 4.3, that contains Commit 655fe4effe0f ("usbcore: add sysfs support to xHCI usb3 hardware LPM"). Signed-off-by: Lu Baolu Signed-off-by: Greg Kroah-Hartman

usb: interface authorization: SysFS part of USB interface authorization

2015-09-22T19:08:40Z

This introduces an attribute for each interface to authorize (1) or deauthorize (0) it: /sys/bus/usb/devices/INTERFACE/authorized Signed-off-by: Stefan Koch Signed-off-by: Greg Kroah-Hartman

Revert "usb: interface authorization: SysFS part of USB interface authorization"

2015-08-18T16:57:43Z

This reverts commit 187b3d75bbfba45a38b5d1d3656c0f11f6f6f2d0 as the signed-off-by address is invalid. Cc: Stefan Koch Signed-off-by: Greg Kroah-Hartman

usb: interface authorization: SysFS part of USB interface authorization

2015-08-14T23:55:54Z

This introduces an attribute for each interface to authorize (1) or deauthorize (0) it: /sys/bus/usb/devices/INTERFACE/authorized Signed-off-by: Stefan Koch Signed-off-by: Greg Kroah-Hartman

usbcore: add sysfs support to xHCI usb3 hardware LPM

2015-07-22T22:45:03Z

Add a sysfs node to make it easier to verify if LPM is supported and being enabled for USB 3.0 devices. Signed-off-by: Kevin Strasser Signed-off-by: Greg Kroah-Hartman

USB / PM: Drop CONFIG_PM_RUNTIME from the USB core

2014-12-03T23:51:54Z

After commit b2b49ccbdd54 (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is selected) PM_RUNTIME is always set if PM is set, so quite a few depend on CONFIG_PM (or even dropped in some cases). Replace CONFIG_PM_RUNTIME with CONFIG_PM in the USB core code and documentation. Signed-off-by: Rafael J. Wysocki Acked-by: Alan Stern Acked-by: Greg Kroah-Hartman

USB: core: correct spelling mistakes in comments and warning

2014-01-08T00:17:40Z

Signed-off-by: Rahul Bedarkar Acked-by: Randy Dunlap Signed-off-by: Greg Kroah-Hartman

usb: Don't enable USB 2.0 Link PM by default.

2013-10-16T19:24:19Z

How it's supposed to work: -------------------------- USB 2.0 Link PM is a lower power state that some newer USB 2.0 devices support. USB 3.0 devices certified by the USB-IF are required to support it if they are plugged into a USB 2.0 only port, or a USB 2.0 cable is used. USB 2.0 Link PM requires both a USB device and a host controller that supports USB 2.0 hardware-enabled LPM. USB 2.0 Link PM is designed to be enabled once by software, and the host hardware handles transitions to the L1 state automatically. The premise of USB 2.0 Link PM is to be able to put the device into a lower power link state when the bus is idle or the device NAKs USB IN transfers for a specified amount of time. ...but hardware is broken: -------------------------- It turns out many USB 3.0 devices claim to support USB 2.0 Link PM (by setting the LPM bit in their USB 2.0 BOS descriptor), but they don't actually implement it correctly. This manifests as the USB device refusing to respond to transfers when it is plugged into a USB 2.0 only port under the Haswell-ULT/Lynx Point LP xHCI host. These devices pass the xHCI driver's simple test to enable USB 2.0 Link PM, wait for the port to enter L1, and then bring it back into L0. They only start to break when L1 entry is interleaved with transfers. Some devices then fail to respond to the next control transfer (usually a Set Configuration). This results in devices never enumerating. Other mass storage devices (such as a later model Western Digital My Passport USB 3.0 hard drive) respond fine to going into L1 between control transfers. They ACK the entry, come out of L1 when the host needs to send a control transfer, and respond properly to those control transfers. However, when the first READ10 SCSI command is sent, the device NAKs the data phase while it's reading from the spinning disk. Eventually, the host requests to put the link into L1, and the device ACKs that request. Then it never responds to the data phase of the READ10 command. This results in not being able to read from the drive. Some mass storage devices (like the Corsair Survivor USB 3.0 flash drive) are well behaved. They ACK the entry into L1 during control transfers, and when SCSI commands start coming in, they NAK the requests to go into L1, because they need to be at full power. Not all USB 3.0 devices advertise USB 2.0 link PM support. My Point Grey USB 3.0 webcam advertises itself as a USB 2.1 device, but doesn't have a USB 2.0 BOS descriptor, so we don't enable USB 2.0 Link PM. I suspect that means the device isn't certified. What do we do about it? ----------------------- There's really no good way for the kernel to test these devices. Therefore, the kernel needs to disable USB 2.0 Link PM by default, and distros will have to enable it by writing 1 to the sysfs file /sys/bus/usb/devices/../power/usb2_hardware_lpm. Rip out the xHCI Link PM test, since it's not sufficient to detect these buggy devices, and don't automatically enable LPM after the device is addressed. This patch should be backported to kernels as old as 3.11, that contain the commit a558ccdcc71c7770c5e80c926a31cfe8a3892a09 "usb: xhci: add USB2 Link power management BESL support". Without this fix, some USB 3.0 devices will not enumerate or work properly under USB 2.0 ports on Haswell-ULT systems. Signed-off-by: Sarah Sharp Cc: stable@vger.kernel.org

drivers: usb: core: {file,hub,sysfs,usb}.c: Whitespace fixes

2013-10-12T00:02:37Z

including: - removing of trailing whitespace - removing spaces before array indexing (foo [] to foo[]) - reindention of a switch-case block - spaces to tabs Signed-off-by: Matthias Beyer Signed-off-by: Greg Kroah-Hartman

USB: fix substandard locking for the sysfs files

2013-09-26T00:27:01Z

This patch straightens out some locking issues in the USB sysfs interface: Deauthorization will destroy existing configurations. Attributes that read from udev->actconfig need to lock the device to prevent races. Likewise for the rawdescriptor values. Attributes that access an interface's current alternate setting should use ACCESS_ONCE() to obtain the cur_altsetting pointer, to protect against concurrent altsetting changes. The supports_autosuspend() attribute routine accesses values from an interface's driver, so it should lock the interface (rather than the usb_device) to protect against concurrent unbinds. Once this is done, the routine can be simplified considerably. Scalar values that are stored directly in the usb_device structure are always available. They do not require any locking. The same is true of the cached interface string descriptor, because it is not deallocated until the usb_host_interface structure is destroyed. Signed-off-by: Alan Stern CC: Hans de Goede Signed-off-by: Greg Kroah-Hartman