[RFC PATCH 0/2] staging: usbip: refine the spinlock

[Harvey Yang <harvey.huawei.yang@gmail.com>]

This patchset refine some spinlocks which I think not used properly. Maybe my 'refine' make the code  broken, so any comments will be appreciated. 

patch1: The function 'usbip_event_add()' may be called in interrupt context on the stub side: 
'stub_complete'->'stub_enqueue_ret_unlink'->'usbip_event_add'.
In this function it tries to get the lock 'ud->lock', so we shoud disable irq when we get this lock in process context.

patch2: On the client side, we have a virtual hcd driver so there actually no hardware interrupts. Maybe to achieve a good performance there is no need to use the interrupt safe spinlock. Just replace them with a non interrupt safe version.


Harvey Yang (2):
  staging: usbip: use interrupt safe spinlock to avoid potential
    deadlock.
  staging: usbip: replace the interrupt safe spinlock because no
    hardware interrupt exists.

 drivers/staging/usbip/stub_dev.c    |   34 ++++++++--------
 drivers/staging/usbip/stub_rx.c     |    4 +-
 drivers/staging/usbip/usbip_event.c |    6 ++-
 drivers/staging/usbip/vhci_hcd.c    |   75 +++++++++++++++--------------------
 drivers/staging/usbip/vhci_rx.c     |   10 ++---
 drivers/staging/usbip/vhci_tx.c     |   14 +++----
 6 files changed, 65 insertions(+), 78 deletions(-)