linux-stable.git/drivers/usb/core/driver.c, branch linux-3.13.y Linux kernel stable tree USB: change dev_warn about missing reset-resume to dev_dbg 2013-10-19T21:10:16+00:00 Alan Stern stern@rowland.harvard.edu 2013-10-18T15:17:21+00:00 0a56b4fa6844f74976d4bfa4956fa6d606b392ea This patch changes a dev_warn() call in usbcore to dev_dbg(). It's not necessary to warn about drivers missing a reset-resume callback, since the reset-resume method is optional. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
This patch changes a dev_warn() call in usbcore to dev_dbg().  It's
not necessary to warn about drivers missing a reset-resume callback,
since the reset-resume method is optional.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: Don't enable USB 2.0 Link PM by default. 2013-10-16T19:24:19+00:00 Sarah Sharp sarah.a.sharp@linux.intel.com 2013-09-30T14:26:28+00:00 de68bab4fa96014cfaa6fcbcdb9750e32969fb86 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 <sarah.a.sharp@linux.intel.com> Cc: stable@vger.kernel.org 
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 <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org
USB: core: use DRIVER_ATTR_RW() 2013-08-23T22:12:14+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2013-08-23T22:12:14+00:00 598d03610a0169eb88d2b08d6743be31b3b9c258 Use DRIVER_ATTR_RW() to make it easier to audit sysfs file permissions. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Use DRIVER_ATTR_RW() to make it easier to audit sysfs file permissions.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: fix some scripts/kernel-doc warnings 2013-08-03T03:30:14+00:00 Yacine Belkadi yacine.belkadi.1@gmail.com 2013-08-02T18:10:04+00:00 626f090c5cbbe557379978c7a9525011ad7fbbf6 When building the htmldocs (in verbose mode), scripts/kernel-doc reports the following type of warnings: Warning(drivers/usb/core/usb.c:76): No description found for return value of 'usb_find_alt_setting' Fix them by: - adding some missing descriptions of return values - using "Return" sections for those descriptions Signed-off-by: Yacine Belkadi <yacine.belkadi.1@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
When building the htmldocs (in verbose mode), scripts/kernel-doc reports the
following type of warnings:

Warning(drivers/usb/core/usb.c:76): No description found for return value of
'usb_find_alt_setting'

Fix them by:
- adding some missing descriptions of return values
- using "Return" sections for those descriptions

Signed-off-by: Yacine Belkadi <yacine.belkadi.1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
PM / Runtime: Rework the "runtime idle" helper routine 2013-06-03T19:49:52+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2013-06-03T19:49:52+00:00 45f0a85c8258741d11bda25c0a5669c06267204a The "runtime idle" helper routine, rpm_idle(), currently ignores return values from .runtime_idle() callbacks executed by it. However, it turns out that many subsystems use pm_generic_runtime_idle() which checks the return value of the driver's callback and executes pm_runtime_suspend() for the device unless that value is not 0. If that logic is moved to rpm_idle() instead, pm_generic_runtime_idle() can be dropped and its users will not need any .runtime_idle() callbacks any more. Moreover, the PCI, SCSI, and SATA subsystems' .runtime_idle() routines, pci_pm_runtime_idle(), scsi_runtime_idle(), and ata_port_runtime_idle(), respectively, as well as a few drivers' ones may be simplified if rpm_idle() calls rpm_suspend() after 0 has been returned by the .runtime_idle() callback executed by it. To reduce overall code bloat, make the changes described above. Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Tested-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Kevin Hilman <khilman@linaro.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Alan Stern <stern@rowland.harvard.edu> 
The "runtime idle" helper routine, rpm_idle(), currently ignores
return values from .runtime_idle() callbacks executed by it.
However, it turns out that many subsystems use
pm_generic_runtime_idle() which checks the return value of the
driver's callback and executes pm_runtime_suspend() for the device
unless that value is not 0.  If that logic is moved to rpm_idle()
instead, pm_generic_runtime_idle() can be dropped and its users
will not need any .runtime_idle() callbacks any more.

Moreover, the PCI, SCSI, and SATA subsystems' .runtime_idle()
routines, pci_pm_runtime_idle(), scsi_runtime_idle(), and
ata_port_runtime_idle(), respectively, as well as a few drivers'
ones may be simplified if rpm_idle() calls rpm_suspend() after 0 has
been returned by the .runtime_idle() callback executed by it.

To reduce overall code bloat, make the changes described above.

Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Kevin Hilman <khilman@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
USB: driver.c: processing failure, maching resume condition with suspend condition 2013-04-01T19:32:43+00:00 Chen Gang gang.chen@asianux.com 2013-04-01T05:04:08+00:00 505bdbc79d20f8f2a56c02498f079bb23b0ef756 when suspend, it need check 'udev->actconfig'. so when process failure, also need check it. Signed-off-by: Chen Gang <gang.chen@asianux.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
  when suspend, it need check 'udev->actconfig'.
  so when process failure, also need check it.

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: remove CONFIG_USB_SUSPEND option 2013-03-28T18:10:22+00:00 Alan Stern stern@rowland.harvard.edu 2013-03-27T20:14:46+00:00 84ebc10294a3d7be4c66f51070b7aedbaa24de9b This patch (as1675) removes the CONFIG_USB_SUSPEND option, essentially replacing it everywhere with CONFIG_PM_RUNTIME (except for one place in hub.c, where it is replaced with CONFIG_PM because the code needs to be used in both runtime and system PM). The net result is code shrinkage and simplification. There's very little point in keeping CONFIG_USB_SUSPEND because almost everybody enables it. The few that don't will find that the usbcore module has gotten somewhat bigger and they will have to take active measures if they want to prevent hubs from being runtime suspended. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: Peter Chen <peter.chen@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
This patch (as1675) removes the CONFIG_USB_SUSPEND option, essentially
replacing it everywhere with CONFIG_PM_RUNTIME (except for one place
in hub.c, where it is replaced with CONFIG_PM because the code needs
to be used in both runtime and system PM).  The net result is code
shrinkage and simplification.

There's very little point in keeping CONFIG_USB_SUSPEND because almost
everybody enables it.  The few that don't will find that the usbcore
module has gotten somewhat bigger and they will have to take active
measures if they want to prevent hubs from being runtime suspended.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: adds comment on suspend callback 2013-03-25T17:55:46+00:00 Ming Lei ming.lei@canonical.com 2013-03-15T04:08:53+00:00 303f0847925ece27129487a2bfc05199ab2a0b51 This patch adds comments on interface driver suspend callback to emphasize that the failure return value is ignored by USB core in system sleep context, so do not try to recover device for this case and let resume/reset_resume callback handle the suspend failure if needed. Also kerneldoc for usb_suspend_both() is updated with the fact. Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
This patch adds comments on interface driver suspend callback
to emphasize that the failure return value is ignored by
USB core in system sleep context, so do not try to recover
device for this case and let resume/reset_resume callback
handle the suspend failure if needed.

Also kerneldoc for usb_suspend_both() is updated with the
fact.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-12-13T20:00:02+00:00 Linus Torvalds torvalds@linux-foundation.org 2012-12-13T20:00:02+00:00 a2013a13e68354e0c8f3696b69701803e13fb737 Pull trivial branch from Jiri Kosina: "Usual stuff -- comment/printk typo fixes, documentation updates, dead code elimination." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits) HOWTO: fix double words typo x86 mtrr: fix comment typo in mtrr_bp_init propagate name change to comments in kernel source doc: Update the name of profiling based on sysfs treewide: Fix typos in various drivers treewide: Fix typos in various Kconfig wireless: mwifiex: Fix typo in wireless/mwifiex driver messages: i2o: Fix typo in messages/i2o scripts/kernel-doc: check that non-void fcts describe their return value Kernel-doc: Convention: Use a "Return" section to describe return values radeon: Fix typo and copy/paste error in comments doc: Remove unnecessary declarations from Documentation/accounting/getdelays.c various: Fix spelling of "asynchronous" in comments. Fix misspellings of "whether" in comments. eisa: Fix spelling of "asynchronous". various: Fix spelling of "registered" in comments. doc: fix quite a few typos within Documentation target: iscsi: fix comment typos in target/iscsi drivers treewide: fix typo of "suport" in various comments and Kconfig treewide: fix typo of "suppport" in various comments ... 
Pull trivial branch from Jiri Kosina:
 "Usual stuff -- comment/printk typo fixes, documentation updates, dead
  code elimination."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  HOWTO: fix double words typo
  x86 mtrr: fix comment typo in mtrr_bp_init
  propagate name change to comments in kernel source
  doc: Update the name of profiling based on sysfs
  treewide: Fix typos in various drivers
  treewide: Fix typos in various Kconfig
  wireless: mwifiex: Fix typo in wireless/mwifiex driver
  messages: i2o: Fix typo in messages/i2o
  scripts/kernel-doc: check that non-void fcts describe their return value
  Kernel-doc: Convention: Use a "Return" section to describe return values
  radeon: Fix typo and copy/paste error in comments
  doc: Remove unnecessary declarations from Documentation/accounting/getdelays.c
  various: Fix spelling of "asynchronous" in comments.
  Fix misspellings of "whether" in comments.
  eisa: Fix spelling of "asynchronous".
  various: Fix spelling of "registered" in comments.
  doc: fix quite a few typos within Documentation
  target: iscsi: fix comment typos in target/iscsi drivers
  treewide: fix typo of "suport" in various comments and Kconfig
  treewide: fix typo of "suppport" in various comments
  ...
usb-core: remove CONFIG_HOTPLUG ifdefs 2012-11-21T21:27:16+00:00 Bill Pemberton wfp5p@virginia.edu 2012-11-19T18:19:16+00:00 2bd6a021e887c675116ff8cdacc3af49999a2224 Remove conditional code based on CONFIG_HOTPLUG being false. It's always on now in preparation of it going away as an option. Signed-off-by: Bill Pemberton <wfp5p@virginia.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Remove conditional code based on CONFIG_HOTPLUG being false.  It's
always on now in preparation of it going away as an option.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>