On Wednesday, July 29, 2015 02:19:16 PM Greg KH wrote: > On Fri, Jun 26, 2015 at 02:32:47PM +0530, Viresh Kumar wrote: > > ->add_dev() may fail and the error returned from it can be useful for > > the caller. > > > > For example, if some of the resources aren't ready yet and -EPROBE_DEFER > > is returned from ->add_dev(), then the owner of 'struct > > subsys_interface' may want to try probing again at a later point of > > time. And that requires a proper return value from ->add_dev(). > > > > Also, if we hit an error while registering subsys_interface, then we > > should stop proceeding further and rollback whatever has been done until > > then. Break part of subsys_interface_unregister() into another routine, > > which lets us call ->remove_dev() for all devices for which ->add_dev() > > is already called. > > > > Cc: 3.3+ <[email protected]> # 3.3+ > > Fixes: ca22e56debc5 ("driver-core: implement 'sysdev' functionality for > > regular devices and buses") > > I don't see how this is a stable bug fix, what is resolved by it that > doesn't work today? Is there some code that is expecting this > functionality that has never been present? > > I'll go queue it up, but I don't think it is -stable material, but feel > free to change my mind.
There is a small problem with it that I've already pointed out to Viresh. Namely, while changing subsys_interface_(un)register() to handle return values from ->add_dev(), it doesn't do the same thing in bus_probe_device() which I believe it should for consistency at least. But then, the question is whether or not the probing should fail and what if device_attach() returns 0 and one of the ->add_dev() callbacks returns an error. Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
