tree 011581a93e3ab32c3feaf2e8d93e9fbd3d23be1e
parent 9c0bb43bbd02fba0b235f8993d1f175734fa8735
author Russell King - ARM Linux <linux@arm.linux.org.uk> 1294093946 +0000
committer Dan Williams <dan.j.williams@intel.com> 1294197370 -0800

ARM: PL08x: fix deadlock in terminate_all

Trying to disable a tasklet while holding a spinlock which the tasklet
will take is a recipe for deadlock - tasklet_disable() will wait for the
tasklet to finish running, which it will never do.  In any case, there
is not a corresponding tasklet_enable(), so once the tasklet is disabled,
it will never run again until reboot.

It's safe to just remove the tasklet_disable() as we remove all current
and pending descriptors before releasing this spinlock.  This means that
the tasklet will find no remaining work if it subsequently runs.

The only remaining issue is that the callback for an already submitted
txd may be in progress, or even called after terminate_all() returns.
There's not much that can be done about that as waiting for the callback
to complete before returning will also lead to deadlocks.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>