With this patch,I can see usb 3.0 device detection is failing on exynos5250-smdk5250 boards. CONFIG_USB_SUSPEND=n / $ [ 11.486922] hub 2-0:1.0: connect-debounce failed, port 1 disabled [ 13.891919] hub 2-0:1.0: connect-debounce failed, port 1 disabled [ 16.296919] hub 2-0:1.0: connect-debounce failed, port 1 disabled [ 18.701919] hub 2-0:1.0: connect-debounce failed, port 1 disabled [ 21.106919] hub 2-0:1.0: connect-debounce failed, port 1 disabled [ 23.511918] hub 2-0:1.0: connect-debounce failed, port 1 disabled [ 25.916918] hub 2-0:1.0: connect-debounce failed, port 1 disabled When I revert this patch, device detection works fine.Anyone have come across the same on other platforms? On Wed, Jan 8, 2014 at 11:49 PM, Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx> wrote: > On Wed, Jan 08, 2014 at 12:49:57PM -0500, Alan Stern wrote: >> On Wed, 8 Jan 2014, Greg KH wrote: >> >> > On Wed, Jan 08, 2014 at 02:45:42PM +0800, Shen Guang wrote: >> > > When we are doing compliance test with xHCI, we found that if we >> > > enable CONFIG_USB_SUSPEND and plug in a bad device which causes >> > > over-current condition to the root port, software will not be noticed. >> > > The reason is that current code don't set hub->change_bits in >> > > hub_activate() when over-current happens, and then hub_events() will >> > > not check the port status because it thinks nothing changed. >> > > If CONFIG_USB_SUSPEND is disabled, the interrupt pipe of the hub will >> > > report the change and set hub->event_bits, and then hub_events() will >> > > check what events happened.In this case over-current can be detected. >> > > >> > > Signed-off-by: Shen Guang <shenguang10@xxxxxxxxx> >> > > --- >> > > drivers/usb/core/hub.c | 3 ++- >> > > 1 file changed, 2 insertions(+), 1 deletion(-) >> > > >> > > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c >> > > index bd9dc35..98b5679 100644 >> > > --- a/drivers/usb/core/hub.c >> > > +++ b/drivers/usb/core/hub.c >> > > @@ -1154,7 +1154,8 @@ static void hub_activate(struct usb_hub *hub, >> > > enum hub_activation_type type) >> > > /* Tell khubd to disconnect the device or >> > > * check for a new connection >> > > */ >> > > - if (udev || (portstatus & USB_PORT_STAT_CONNECTION)) >> > > + if (udev || (portstatus & USB_PORT_STAT_CONNECTION) || >> > > + (portstatus & USB_PORT_STAT_OVERCURRENT)) >> > > set_bit(port1, hub->change_bits); >> > > >> > > } else if (portstatus & USB_PORT_STAT_ENABLE) { >> > > -- >> > > 1.7.9.5 >> > >> > Alan and Sarah, any objection to this patch? >> >> It seems okay to me. >> >> Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > > Looks fine to me as well. > > Acked-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx> > -- > 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 -- 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