This removes the last usage of the Big Kernel Lock from the ieee1394
stack, i.e. from raw1394's (unlocked_)ioctl and compat_ioctl.
The ioctl()s don't need to take the BKL, but they need to be serialized
per struct file *. In particular, accesses to ->iso_state need to be
serial. We simply use a blocking mutex for this purpose because
libraw1394 does not use O_NONBLOCK. In practice, there is no lock
contention anyway because most if not all libraw1394 clients use a
libraw1394 handle only in a single thread.
mmap() also accesses ->iso_state. Until now this was unprotected
against concurrent changes by ioctls. Fix this bug while we are at it.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Based on patch "the scheduled removal of RAW1394_REQ_ISO_{SEND,LISTEN}"
from Adrian Bunk, November 20 2006.
This patch also removes the underlying facilities in ohci1394 and
disables them in pcilynx. That is, hpsb_host_driver.devctl() and
hpsb_host_driver.transmit_packet() are no longer used for iso reception
and transmission.
Since video1394 and dv1394 only work with ohci1394 and raw1394's rawiso
interface has never been implemented in pcilynx, pcilynx is now no
longer useful for isochronous applications.
raw1394 will still handle the request types but will complete the
requests with errors that indicate API version conflicts.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
An already existing wait queue replaces raw1394's complete_sem which was
maintained in parallel to the wait queue. The role of the semaphore's
counter is taken over by a direct check of what was really counted: The
presence of items in the list of completed requests.
Notes:
- raw1394_release() sleeps uninterruptibly until all requests were
completed. This is the same behaviour as before the patch.
- The macros wait_event and wait_event_interruptible are called with a
condition argument which has a side effect, i.e. manipulation of the
requests list. This side effect happens only if the condition is
true. The patch relies on the fact that wait_event[_interruptible]
does not evaluate the condition again after it became true.
- The diffstat looks unfavorable with respect to added lines of code.
However 19 of them are comments, and some are due to separation of
existing code blocks into two small helper functions.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Ben Collins <bcollins@ubuntu.com>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Stefan Richter
Linus Torvalds