On Tue, Oct 27, 2009 at 10:24:22AM -0400, eschvoca@xxxxxxxxx wrote: > Hi Paul, > On Tue, Oct 27, 2009 at 1:00 AM, Paul E. McKenney < > paulmck@xxxxxxxxxxxxxxxxxx> wrote: > > > 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.) > > If you are recommending I put in a prink() then I will need a patch. Also > tell me what information you want me to collect. I'm just an avid Linux > fan/user that would really like my keyboard/USB devices to work on boot-up. Fair enough. Could you please send me your .config? The output of "grep RCU .config" will suffice. I also need to know what version of the kernel you are using -- looks like 2.6.28, but please let me know. Thanx, Paul -- 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
