Re: [PATCH 2/2] usb/core: update power budget for SuperSpeed

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On Wed, 5 Dec 2012, Sebastian Andrzej Siewior wrote:

> Sarah pointed out that the USB3.0 spec also updates the amount of power
> that may be consumed by the device and quoted 9.2.5.1:
> 
> |"The amount of current draw for SuperSpeed devices are increased to 150
> |mA for low-power devices and 900 mA for high-power"
> 
> This patch tries to update all users to use the larger values for
> SuperSpeed devices and use the "old" ones for everything else.
> 
> While here, two other changes suggested by Alan:
> - the comment referering to 7.2.1.1 has been updated to 7.2.1 which is
>   the correct source of the action.
> - the check for hubs with zero ports has been removed.

> @@ -4145,16 +4154,21 @@ hub_power_remaining (struct usb_hub *hub)
>  	for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
>  		struct usb_device	*udev = hub->ports[port1 - 1]->child;
>  		int			delta;
> +		unsigned		unit_load;
>  
>  		if (!udev)
>  			continue;
> +		if (hub_is_superspeed(udev))
> +			unit_load = 150;
> +		else
> +			unit_load = 100;
>  
>  		/* Unconfigured devices may not use more than 100mA,
>  		 * or 8mA for OTG ports */

This comment should be updated too (one unit load instead of 100mA).  
BTW, does OTG support SuperSpeed?

Alan Stern

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