On Thu, Jul 20, 2017 at 05:06:22PM -0500, Rob Herring wrote: > This reverts commit d2180e0cf77dc7a7049671d5d57dfa0a228f83c1. > > The commit was flawed in that if the device_node pointers are different, > then in fact a different device is present and the device node could be > different in ways other than full_name. > > As Frank Rowand explained: > > "When an overlay (1) is removed, all uses and references to the nodes and > properties in that overlay are no longer valid. Any driver that uses any > information from the overlay _must_ stop using any data from the overlay. > Any driver that is bound to a new node in the overlay _must_ unbind. Any > driver that became bound to a pre-existing node that was modified by the > overlay (became bound after the overlay was applied) _must_ adjust itself > to account for any changes to that node when the overlay is removed. One > way to do this is to unbind when notified that the overlay is about to > be removed, then to re-bind after the overlay is completely removed. > > If an overlay (2) is subsequently applied, a node with the same > full_name as from overlay (1) may exist. There is no guarantee > that overlay (1) and overlay (2) are the same overlay, even if > that node has the same full_name in both cases." > > Also, there's not sufficient overlay support in mainline to actually > remove and re-apply an overlay to hit this condition as overlays can > only be applied from in kernel APIs. > > Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx> > Cc: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> > Cc: Javi Merino <javi.merino@xxxxxxxxxx> > Cc: Javier Martinez Canillas <javier@xxxxxxxxxxxxxxx> > Cc: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx> > Cc: Frank Rowand <frowand.list@xxxxxxxxx> > Signed-off-by: Rob Herring <robh@xxxxxxxxxx> I've been trying to reproduce the original issues that I had for a couple of hours and I am not able to any more, so I can't object to the patch. The explanation from Frank Rowand is sound so: Acked-by: Javi Merino <javi.merino@xxxxxxxxxx> > --- > Mauro, please apply this for 4.13. It could be marked for stable, too, > but it's not going to apply cleanly with the fwnode changes. > > Rob > > drivers/media/v4l2-core/v4l2-async.c | 7 +------ > 1 file changed, 1 insertion(+), 6 deletions(-)
