On Tue, 11 Jan 2011, Pratyush Anand wrote:
> >> I am working with controller where it expects port power off to be
> >> done by software in case of overcurrent detection interrupt.
> >
> > Root hubs are different from external hubs. It is reasonable to expect
> > software to turn off port power for root hubs.
> >
>
> The code which I had referred was from linux (except hub_power_off part).
>
> linux+v2.6.37/drivers/usb/core/hub.c
> line no: 3416
>
> 3416 if (hubchange & HUB_CHANGE_OVERCURRENT) {
> 3417 dev_dbg (hub_dev, "overcurrent change\n");
> 3418 msleep(500); /* Cool down */
> 3419 clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
> 3420 hub_power_on(hub, true);
> 3421 }
> 3422 }
>
> But, It does not turn off port power for root hubs.
If you want to add a hub_power_off() call in there, I don't think
anyone will object. Especially if you call it only for root hubs. Is
that sufficient to make your controller work?
Alan Stern
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