Re: [RFC PATCH 1/2] usb: usb port power off mechanism add "auto" option

[Lan Tianyu]

于 2012/8/22 22:39, Alan Stern 写道:

On Wed, 22 Aug 2012, Lan Tianyu wrote:

You forgot to change the logic in hub_power_on().  You have to handle
the USB_PORT_POWER_AUTO case.

Yeah. Thanks for reminder.
How about following?

@@ -858,7 +860,14 @@ static unsigned hub_power_on(struct usb_hub *hub,
bool do_delay)
        if (hub->ports[port1 - 1]->port_power_policy
                        == USB_PORT_POWER_ON)
                set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
-      else
+      else if (hub->ports[port1 - 1]->port_power_policy
+                       == USB_PORT_POWER_AUTO) {
+               if (hub->ports[port1 - 1]->connect_type
+                               == USB_PORT_NOT_USED
+                               && !hub->ports[port1 - 1]->child)
+                       clear_port_feature(hub->hdev, port1,
+                                       USB_PORT_FEAT_POWER);
+               } else
                         clear_port_feature(hub->hdev, port1,
                                         USB_PORT_FEAT_POWER);

This doesn't handle all the cases, and it has duplicated code.  It
would be better to do something like this:

        p = &hub->ports[port1 - 1];
        if (p->port_power_policy == USB_PORT_POWER_OFF ||
                        (p->port_power_policy == USB_PORT_POWER_AUTO &&
                                p->connect_type == USB_PORT_NOT_USED &&
                                !p->child))
                clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
        else
                set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);

Alan Stern

OK. I get it. Thanks.

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