Re: [RFC PATCH] usb/acpi: Add support usb port power off mechanism for device fixed on the motherboard

Greg KH
2012-05-15T15:18:00Z

On Tue, May 15, 2012 at 10:31:38PM +0800, Lan Tianyu wrote:
> Since alan suggested we should start simpler version(power
> down port that have no devices attached) firstly. And we
> also should provide general power off mechanism.
>
> I have a proposal.
> first: add portx_power_control sys file.
> echo "auto" => portx_power_control
> check whether there is a device. if no, send the clear
> USB_PORT_FEAT_POWER request. (since general way
> to control port power is via set or clear PORT_POWER)
>
> echo "on" => portx_power_control
> send the set USB_PORT_FEAT_POWER request.

No "off"?

> second:
> In the xhci driver, add acpi hook in the xhci_hub_control()
> where USB_PORT_FEAT_POWER request is dealt with.

Do you have a patch showing that this works?

greg k-h
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