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| author | Sarah Sharp <sarah.a.sharp@linux.intel.com> | 2012-10-04 20:53:43 +0400 |
|---|---|---|
| committer | Sarah Sharp <sarah.a.sharp@linux.intel.com> | 2012-10-08 22:47:40 +0400 |
| commit | d01f87c0ffa96cb44faa78710711eb6e974b891c (patch) | |
| tree | 9016b46d3d84a9deaf402de534c48820787fd266 /drivers/usb/core/driver.c | |
| parent | ecefbd94b834fa32559d854646d777c56749ef1c (diff) | |
| download | linux-d01f87c0ffa96cb44faa78710711eb6e974b891c.tar.xz | |
USB: Enable LPM after a failed probe.
Before a driver is probed, we want to disable USB 3.0 Link Power
Management (LPM), in case the driver needs hub-initiated LPM disabled.
After the probe finishes, we want to attempt to re-enable LPM, order to
balance the LPM ref count.
When a probe fails (such as when libusual doesn't want to bind to a USB
3.0 mass storage device), make sure to balance the LPM ref counts by
re-enabling LPM.
This patch should be backported to kernels as old as 3.5, that contain
the commit 8306095fd2c1100e8244c09bf560f97aca5a311d "USB: Disable USB
3.0 LPM in critical sections."
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org
Diffstat (limited to 'drivers/usb/core/driver.c')
| -rw-r--r-- | drivers/usb/core/driver.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index ddd820d25288..6056db7af410 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -367,6 +367,10 @@ static int usb_probe_interface(struct device *dev) intf->condition = USB_INTERFACE_UNBOUND; usb_cancel_queued_reset(intf); + /* If the LPM disable succeeded, balance the ref counts. */ + if (!lpm_disable_error) + usb_unlocked_enable_lpm(udev); + /* Unbound interfaces are always runtime-PM-disabled and -suspended */ if (driver->supports_autosuspend) pm_runtime_disable(dev); |