Re: [PATCH] usb:hub set hub->change_bits when over-current happens

[Yuvaraj Cd]

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>
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