Re: [PATCH 1/2] USB: check port changes before hub runtime suspend

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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.

> 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.

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.

Thanks
--
Ming Lei
--
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


[Index of Archives]     [Linux Media]     [Linux Input]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Old Linux USB Devel Archive]

  Powered by Linux