linux/drivers/media
Darron Broad 59b1842da1 V4L/DVB (9227): MFE: Add multi-frontend mutual exclusion
This add frontend R/W mutual exclusion.
Prior to this point in time it was possible to open both
frontends simultaneously which an MFE card cannot support.

In order to stop this, a delayed open is performed which
has the following function:

-  Return EBUSY after a configurable amount of time
   if a frontend is unavailable due to the other being
   in use.

-  Only allow opening of a frontend if the kernel thread
   of the other has stopped.

This solution was chosen to allow switching between
frontends to work as seamlessly as possible. When both
frontends are actually opened simultaneously then one
will only open, but if quick switching is performed
between one of many then the new open will succeed in
a clean fashion rather than interrupting a kernel
thread.

Signed-off-by: Darron Broad <darron@kewl.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-10-17 17:24:15 -03:00
..
common V4L/DVB (9168): Add support for MSI TV@nywhere Plus remote 2008-10-13 09:57:34 -02:00
dvb V4L/DVB (9227): MFE: Add multi-frontend mutual exclusion 2008-10-17 17:24:15 -03:00
radio V4L/DVB (9219): Kernel config comment corrected (radio-silabs -> radio-si470x) 2008-10-17 17:22:54 -03:00
video V4L/DVB (9227): MFE: Add multi-frontend mutual exclusion 2008-10-17 17:24:15 -03:00
Kconfig V4L/DVB (8392): media/Kconfig: Convert V4L1_COMPAT select into "depends on" 2008-07-20 07:28:49 -03:00
Makefile V4L/DVB (8274): sms1xxx: build cleanup after driver relocation 2008-07-20 07:20:56 -03:00