> Bad news, even with the rwsem after a lot more testing I can still > trigger the hang in ohci_hub_control() :-( > > I think we need to go back to considering the total serialization > approach to this problem.
We shouldn't need that. What happens if you add an msleep(5) before ehci-hcd::ehci_run() drops ehci_cf_port_reset_rwsem? The theory there being that the switch triggered by setting CF doesn't take effect instantaneously, contrary to the effective assumption of that code. A delay of 5 msec seems like it should be more than enough, but that's kind of a guess ... it's good to keep that low, since unfortunately that's in the critical path for OLPC "resume from idle". - Dave - 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/
