On Mon, Oct 26, 2009 at 09:33:33PM -0700, Arjan van de Ven wrote: > On Mon, 26 Oct 2009 22:31:16 -0400 > eschvoca <eschvoca@xxxxxxxxx> wrote: > > > Hi Oliver, > > > > (Adding cc: Arjan) > > > > On Wed, Oct 14, 2009 at 10:54 PM, eschvoca <eschvoca@xxxxxxxxx> wrote: > > > Hi Oliver, > > > > > > It ends up that the problem happens sporadically -- some reboots the > > > keyboard and bluetooth adapter don't work while other reboots it > > > does. I tried variations of reboot vs suspend vs shutdown vs unplug > > > power and couldn't find a repeatable pattern. Perhaps the problem > > > is related to Ubuntu trying to speed up the boot process which > > > doesn't wait long enough for the USB devices to respond. My mouse > > > always works while my USB bluetooth dongle and keyboard (through a > > > GASIA PS2toUSB Adapter) do not. > > > > > > I've been looking for a guide on how to do a "git bisect" on vanilla > > > kernels on ubuntu but haven't found anything that works well. I > > > compiled a vanilla kernel but when I went to install the debs I was > > > warned that there already was a 2.6.28 kernel there and I would > > > overwrite it. I would like to do a "git bisect" on the vanilla > > > kernel and be able to install them without conflicts. Currently > > > the problem is showing up in about 25% of reboots. > > > > > > Please direct. > > > > > > Thanks. > > > > After 16 bisects I tracked down the problem with my USB keyboard > > adapter and USB bluetooth dongle not initializing on boot-up to this > > commit: > > my fear is the following: something ELSE in the system is missing a > synchronize_rcu(), and this case happened to save it by virtue of being > spurious. > > Paul: do we call synchronize_rcu() before we go to userspace for the > first time somewhere? In many cases, yes. But I don't know of a specific synchronize_rcu() that is guaranteed to be executed before the first userspace execution on all kernel configurations for all architectures. I recommend putting a printk() in synchronize_rcu() to check up on this on the system in question. (Or a WARN_ON_ONCE() if log space is limited.) Thanx, Paul > Also.. in theory your X will get this sort of information from HAL, and > HAL will get it on demand as devices show up. I doubt Ubuntu has broken > that too much :) > > > -- > Arjan van de Ven Intel Open Source Technology Centre > For development, discussion and tips for power savings, > visit http://www.lesswatts.org -- 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
