[pvrusb2] Driver status as of 25-Mar-2006

[Mike Isely]

To all:

Here's an update about what is going on with the pvrusb2 driver.

1. I have been steadily chipping away at getting the new model 24xxx
    series hardware working with the driver.  Last week's snapshot had
    a number of changes for that, but not everything.  In particular
    there is a stability problem during initialization involving the
    cx25840 decoder chip; I still don't have good traction on this.
    I'm afraid I'm not going to figure this out for a while yet.

    During this entire time I've had two separate sets of driver
    sources.  One is the "mainline" and the other has the changes for
    the newer hardware.  What I've been doing is merging changes back
    to the main tree one at a time as I prove in each piece (at least
    to the point where I know it doesn't harm anything).  As of this
    afternoon, I've fully merged it all back together.  The last bit
    was work to figure out how to get composite and s-video inputs
    working - the branched driver had test code to support figuring
    that out and I didn't want that code to get back into the mainline.
    There are still some fixes to be done, but it can all be done in
    the main area now.


2. There has been work going on to get the driver into the main V4L
    source tree, and subsequently into the kernel source tree.  The
    plan right now is that the driver will show up in the 2.6.17
    kernel.  The driver sources were moved into the main V4L tree a few
    weeks ago, but some coding / structural issues are holding it back
    from being submitted to the kernel.  When the 2.6.16 kernel was
    finally released last week, a 2 week merge window opened for
    getting new features into 2.6.17.  It's during that time when I
    have to do the remaining fixes here.  I'm hoping to do that this
    weekend; if not then the driver may not make it in time.


3. Hans Verkuil has been making changes to the way audio selection
    routing (e.g. tuner vs RCA jacks) is handled in V4L.  He reworked
    msp3400 to do this 'right' and has since made changes to the
    pvrusb2 driver (in V4L) to track these changes.  He has a second
    round of changes that do a similar job for saa7115.  Since I'm also
    maintaining pvrusb2 as a standalone driver, I need to pull these
    changes back so that the standalone driver will continue to work
    correctly going forward.  Though these changes should not be gating
    the work towards 2.6.17, the fact is that I really can't attack the
    remaining changes needed for (2) until I have everything merged
    back together, so I need to merge Hans' changes into the standalone
    driver.  I also plan on doing that this weekend.


4. The pvrusb2 web site, though not technically inaccurate, has a
    growing list of improvements I need to do.  In particular, I need
    to add lots of info about making the newer hardware work correctly,
    but rather than just do that I'd prefer to rework the entire site
    so that it can be more easily understood.  I haven't done anything
    with that yet.  Unfortunately that work is still probably at least
    a week away.


The current situation with the new hardware is that it can be made to
work, and the driver has all the changes merged now needed to make it
work.  However I still have an unsolved stability problem with
cx25840.  I've been trying for the past week to nail down this problem
but so far I haven't been very successful.  Worse still, I think I
might have found a way to produce a similar stability problem on *old*
hardware using msp3400.  (But I don't think people haven't been
generally seeing a problem there because of a coincidental way in
which the pvrusb2 driver loads the modules, which seems to lower the
chance of failure.)

Regardless, the next snapshot of the driver should include all the
changes needed to operate the new hardware.

   -Mike

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