On Fri, 21 Sep 2012, Ming Lei wrote: > On Fri, Sep 21, 2012 at 1:04 AM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > > > I vaguely remember seeing this same effect with one of my hubs. If a > > port status change occurred before the hub was suspended, the hub would > > not issue a remote wakeup request. This was a bug in the hub. Other > > Looks it is a bug of the hub, see below. Like I said. > > hubs behaved better. > > > >> This patch can fix the problem in the above case. > > > > What happens if you put the msleep(10000) after the new > > check_ports_change() call? > > If a new device is connected into the '05e3:0608 Genesys Logic, Inc. > USB-2.0 4-Port HUB' during this 10sec, the new connection can't > trigger a remote wakeup interrupt from ehci. So your patch does not fix the problem, although it does make the problem less likely to occur. > But If it is connected into the hub of '0424:9514 Standard Microsystems Corp' > during the period, it will cause a ehci remote wakeup interrupt. > > Looks we need to introduce a quirk to fix the bug hub. > > If you have no objection, I will figure out a new patch to fix the bug > device. If you can figure out a patch, I'll be surprised. As far as I can see there is _no_ way to fix this bug. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
