Hi again,
Jonathan Nieder wrote:
> Huber Andreas wrote[1]:
>> Processes that try to open a cx88-blackbird driven MPEG device will hang up.
>
> Here's a possible fix based on a patch by Ben Hutchings and
> corrections from Andi Huber. Warning: probably full of mistakes (my
> fault) since I'm not familiar with any of this stuff. Untested.
> Review and testing would be welcome.
A reroll. As before, the goals are: (1) eliminate deadlock, (2)
eliminate races, (3) introduce some clarity. The same caveats as
last time apply --- this is only compile-tested. Thanks again to Andi
for testing the previous series and for other useful feedback.
Patch 1 is meant to protect dev->drvlist against data races.
Since v1, I removed some clutter in the patch itself and clarified the
change description to match.
Patch 2 addresses the original deadlock. The only changes are the
description and declared authorship of the patch (at Ben's request).
Patch 3 is new. It fixes the reference count breakage Andi noticed
(another race previously protected against by the BKL).
Patch 4 fixes a data race noticed by Ben (also from his patch). It's
unchanged.
Patches 5, 6, and 7 are cleanups.
Bugs? Thoughts?
Jonathan Nieder (7):
[media] cx88: protect per-device driver list with device lock
[media] cx88: fix locking of sub-driver operations
[media] cx88: hold device lock during sub-driver initialization
[media] cx88: use a mutex to protect cx8802_devlist
[media] cx88: handle attempts to use unregistered cx88-blackbird
driver
[media] cx88: don't use atomic_t for core->mpeg_users
[media] cx88: don't use atomic_t for core->users
drivers/media/video/cx88/cx88-blackbird.c | 41 +++++++++++++++-------------
drivers/media/video/cx88/cx88-dvb.c | 2 +
drivers/media/video/cx88/cx88-mpeg.c | 40 ++++++++++++++++++----------
drivers/media/video/cx88/cx88-video.c | 5 ++-
drivers/media/video/cx88/cx88.h | 11 +++++--
5 files changed, 61 insertions(+), 38 deletions(-)
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
