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| author | Sarah Sharp <sarah.a.sharp@linux.intel.com> | 2010-12-29 22:03:07 -0800 |
|---|---|---|
| committer | Sarah Sharp <sarah.a.sharp@linux.intel.com> | 2011-03-13 18:07:07 -0700 |
| commit | db7c7c0aeef51dba12d877875b8deb78d9886647 (patch) | |
| tree | 09567f469abcb49861ab347ffae0685b26836db6 /drivers/usb | |
| parent | fbf9865c6d96f4a131092d2018056e86113e5cea (diff) | |
| download | linux-db7c7c0aeef51dba12d877875b8deb78d9886647.tar.gz linux-db7c7c0aeef51dba12d877875b8deb78d9886647.tar.bz2 linux-db7c7c0aeef51dba12d877875b8deb78d9886647.zip | |
usb: Always return 0 or -EBUSY to the runtime PM core.
The PM core reacts badly when the return code from usb_runtime_suspend()
is not 0, -EAGAIN, or -EBUSY. The PM core regards this as a fatal error,
and refuses to run anymore PM helper functions. In particular,
usbfs_open() and other usbfs functions will fail because the PM core will
return an error code when usb_autoresume_device() is called. This causes
libusb and/or lsusb to either hang or segfault.
If a USB device cannot suspend for some reason (e.g. a hub doesn't report
it has remote wakeup capabilities), we still want lsusb and other
userspace programs to work. So return -EBUSY, which will fill people's
log files with failed tries, but will ensure userspace still works.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/core/driver.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index fca61720b873..38072e4e74bd 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -1659,6 +1659,11 @@ static int usb_runtime_suspend(struct device *dev) return -EAGAIN; status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND); + /* The PM core reacts badly unless the return code is 0, + * -EAGAIN, or -EBUSY, so always return -EBUSY on an error. + */ + if (status != 0) + return -EBUSY; return status; } |