Merge git://git.denx.de/u-boot-usb

common/usb.c

@@ -34,7 +34,7 @@
 #include <asm/byteorder.h>
 #include <asm/unaligned.h>
 #include <compiler.h>
-
+#include <errno.h>
 #include <usb.h>
 #ifdef CONFIG_4xx
 #include <asm/4xx_pci.h>
@@ -60,6 +60,7 @@ int usb_init(void)
 	void *ctrl;
 	struct usb_device *dev;
 	int i, start_index = 0;
+	int ret;
 
 	dev_index = 0;
 	asynch_allowed = 1;
@@ -75,7 +76,13 @@ int usb_init(void)
 	for (i = 0; i < CONFIG_USB_MAX_CONTROLLER_COUNT; i++) {
 		/* init low_level USB */
 		printf("USB%d:   ", i);
-		if (usb_lowlevel_init(i, USB_INIT_HOST, &ctrl)) {
+		ret = usb_lowlevel_init(i, USB_INIT_HOST, &ctrl);
+		if (ret == -ENODEV) {	/* No such device. */
+			puts("Port not available.\n");
+			continue;
+		}
+
+		if (ret) {		/* Other error. */
 			puts("lowlevel init failed\n");
 			continue;
 		}

common/usb_hub.c

@@ -209,9 +209,22 @@ int hub_port_reset(struct usb_device *dev, int port,
 		      (portstatus & USB_PORT_STAT_CONNECTION) ? 1 : 0,
 		      (portstatus & USB_PORT_STAT_ENABLE) ? 1 : 0);
 
-		if ((portchange & USB_PORT_STAT_C_CONNECTION) ||
-		    !(portstatus & USB_PORT_STAT_CONNECTION))
-			return -1;
+		/*
+		 * Perhaps we should check for the following here:
+		 * - C_CONNECTION hasn't been set.
+		 * - CONNECTION is still set.
+		 *
+		 * Doing so would ensure that the device is still connected
+		 * to the bus, and hasn't been unplugged or replaced while the
+		 * USB bus reset was going on.
+		 *
+		 * However, if we do that, then (at least) a San Disk Ultra
+		 * USB 3.0 16GB device fails to reset on (at least) an NVIDIA
+		 * Tegra Jetson TK1 board. For some reason, the device appears
+		 * to briefly drop off the bus when this second bus reset is
+		 * executed, yet if we retry this loop, it'll eventually come
+		 * back after another reset or two.
+		 */
 
 		if (portstatus & USB_PORT_STAT_ENABLE)
 			break;