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  1. 17 4月, 2013 2 次提交
    • D
      Bluetooth: hidp: remove unused session->state field · dcc07647
      由 David Herrmann 提交于 
      This field is always BT_CONNECTED. Remove it and set it to BT_CONNECTED in
hidp_copy_session() unconditionally.

Also note that this field is totally bogus. Userspace can query an
hidp-session for its state. However, whenever user-space queries us, this
field should be BT_CONNECTED. If it wasn't BT_CONNECTED, then we would be
currently cleaning up the session and the session itself would exit in the
next few milliseconds. Hence, there is no reason to let user-space know
that the session will exit now if they cannot make _any_ use of that.

Thus, remove the field and let user-space think that a session is always
BT_CONNECTED as long as they can query it.
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
      dcc07647
    • D
      Bluetooth: remove unneeded hci_conn_hold/put_device() · fc225c3f
      由 David Herrmann 提交于 
      hci_conn_hold/put_device() is used to control when hci_conn->dev is no
longer needed and can be deleted from the system. Lets first look how they
are currently used throughout the code (excluding HIDP!).

All code that uses hci_conn_hold_device() looks like this:
    ...
    hci_conn_hold_device();
    hci_conn_add_sysfs();
    ...
On the other side, hci_conn_put_device() is exclusively used in
hci_conn_del().

So, considering that hci_conn_del() must not be called twice (which would
fail horribly), we know that hci_conn_put_device() is only called _once_
(which is in hci_conn_del()).
On the other hand, hci_conn_add_sysfs() must not be called twice, either
(it would call device_add twice, which breaks the device, see
drivers/base/core.c). So we know that hci_conn_hold_device() is also
called only once (it's only called directly before hci_conn_add_sysfs()).

So hold and put are known to be called only once. That means we can safely
remove them and directly call hci_conn_del_sysfs() in hci_conn_del().

But there is one issue left: HIDP also uses hci_conn_hold/put_device().
However, this case can be ignored and simply removed as it is totally
broken. The issue is, the only thing HIDP delays with
hci_conn_hold_device() is the removal of the hci_conn->dev from sysfs.
But, the hci_conn device has no mechanism to get notified when its own
parent (hci_dev) gets removed from sysfs. hci_dev_hold/put() does _not_
control when it is removed but only when the device object is created
and destroyed.
And hci_dev calls hci_conn_flush_*() when it removes itself from sysfs,
which itself causes hci_conn_del() to be called, but it does _not_ cause
hci_conn_del_sysfs() to be called, which is wrong.

Hence, we fix it to call hci_conn_del_sysfs() in hci_conn_del(). This
guarantees that a hci_conn object is removed from sysfs _before_ its
parent hci_dev is removed.

The changes to HIDP look scary, wrong and broken. However, if you look at
the HIDP session management, you will notice they're already broken in the
exact _same_ way (ever tried "unplugging" HIDP devices? Breaks _all_ the
time).
So this patch only makes HIDP look _scary_ and _obviously broken_. It does
not break HIDP itself, it already is!

See later patches in this series which fix HIDP to use proper
session-management.
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
      fc225c3f
  3. 06 4月, 2013 1 次提交
  5. 08 3月, 2013 1 次提交
  7. 10 1月, 2013 1 次提交
  9. 07 12月, 2012 1 次提交
  11. 28 9月, 2012 1 次提交
  13. 10 6月, 2012 1 次提交
  15. 05 6月, 2012 2 次提交
  17. 01 5月, 2012 2 次提交
  19. 19 12月, 2011 1 次提交
  21. 08 11月, 2011 3 次提交
  23. 07 10月, 2011 10 次提交
  25. 28 9月, 2011 1 次提交
  27. 21 9月, 2011 1 次提交
  29. 12 8月, 2011 4 次提交
  31. 01 7月, 2011 1 次提交
    • P
      Bluetooth: Fix hidp disconnect deadlocks and lost wakeup · 7bb59df8
      由 Peter Hurley 提交于 
      Partial revert of commit aabf6f89. When the hidp session thread
was converted from kernel_thread to kthread, the atomic/wakeups
were replaced with kthread_stop. kthread_stop has blocking semantics
which are inappropriate for the hidp session kthread. In addition,
the kthread signals itself to terminate in hidp_process_hid_control()
- it cannot do this with kthread_stop().

Lastly, a wakeup can be lost if the wakeup happens between checking
for the loop exit condition and setting the current state to
TASK_INTERRUPTIBLE. (Without appropriate synchronization mechanisms,
the task state should not be changed between the condition test and
the yield - via schedule() - as this creates a race between the
wakeup and resetting the state back to interruptible.)
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>
      7bb59df8
  33. 28 4月, 2011 1 次提交
  35. 05 4月, 2011 1 次提交
  37. 01 4月, 2011 1 次提交
  39. 22 2月, 2011 1 次提交
  41. 15 2月, 2011 1 次提交
  43. 11 2月, 2011 2 次提交