@@ -111,11 +111,47 @@ static void usb_hub_power_on(struct usb_hub_device *hub)
int i;
struct usb_device *dev;
unsigned pgood_delay = hub->desc.bPwrOn2PwrGood * 2;
+ ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
+ unsigned short portstatus;
+ int ret;
dev = hub->pusb_dev;
/* Enable power to the ports */
USB_HUB_PRINTF("enabling power on all ports\n");
for (i = 0; i < dev->maxchild; i++) {
+ /*
+ * Power-cycle the ports here: aka,
+ * turning them off and turning on again.
+ */
+ usb_clear_port_feature(dev, i + 1, USB_PORT_FEAT_POWER);
+ USB_HUB_PRINTF("port %d returns %lX\n", i + 1, dev->status);
+
+ /* Wait at least 2*bPwrOn2PwrGood for PP to change */
+ mdelay(pgood_delay);
+
+ ret = usb_get_port_status(dev, i + 1, portsts);
+ if (ret < 0) {
+ USB_HUB_PRINTF("port %d: get_port_status failed\n",
+ i + 1);
+ return;
+ }
+
+ /*
+ * Check to confirm the state of Port Power:
+ * xHCI says "After modifying PP, s/w shall read
+ * PP and confirm that it has reached the desired state
+ * before modifying it again, undefined behavior may occur
+ * if this procedure is not followed".
+ * EHCI doesn't say anything like this, but no harm in keeping
+ * this.
+ */
+ portstatus = le16_to_cpu(portsts->wPortStatus);
+ if (portstatus & (USB_PORT_STAT_POWER << 1)) {
+ USB_HUB_PRINTF("port %d: Port power change failed\n",
+ i + 1);
+ return;
+ }
+
usb_set_port_feature(dev, i + 1, USB_PORT_FEAT_POWER);
USB_HUB_PRINTF("port %d returns %lX\n", i + 1, dev->status);
}