(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;