USB: for usb_autopm_get_interface_async -EINPROGRESS is not an error

BugLink: http://bugs.launchpad.net/bugs/890952

commit c5a48592d874ddef8c7880311581eccf0eb30c3b upstream.

A return value of -EINPROGRESS from pm_runtime_get indicates that
the device is already resuming due to a previous call.  Internally,
usb_autopm_get_interface_async doesn't treat this as an error and
increments the usage count, but passes the error status along
to the caller.  The logical assumption of the caller is that
any negative return value reflects the device not resuming
and the pm_usage_cnt not being incremented.  Since the usage count
is being incremented and the device is resuming, return success (0)
instead.

Signed-off-by: James Wylder <james.wylder@motorola.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 34e3da5aa72..14b83f2a4e8 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -1583,7 +1583,7 @@ int usb_autopm_get_interface_async(struct usb_interface *intf)
         dev_vdbg(&intf->dev, "%s: cnt %d -> %d\n",
                         __func__, atomic_read(&intf->dev.power.usage_count),
                         status);
-        if (status > 0)
+        if (status > 0 || status == -EINPROGRESS)
                 status = 0;
         return status;
 }