- return -EAGAIN;
-
- /* re-init operational registers in case we lost power */
- if (readl (&ehci->regs->intr_enable) == 0) {
- writel (INTR_MASK, &ehci->regs->intr_enable);
- writel (0, &ehci->regs->segment);
- writel (ehci->periodic_dma, &ehci->regs->frame_list);
- writel ((u32)ehci->async->qh_dma, &ehci->regs->async_next);
- /* FIXME will this work even (pci) vAUX was lost? */
- }
+ msleep(5);
+ spin_lock_irq (&ehci->lock);
+
+ /* Ideally and we've got a real resume here, and no port's power
+ * was lost. (For PCI, that means Vaux was maintained.) But we
+ * could instead be restoring a swsusp snapshot -- so that BIOS was
+ * the last user of the controller, not reset/pm hardware keeping
+ * state we gave to it.
+ */
+ temp = readl(&ehci->regs->intr_enable);
+ ehci_dbg(ehci, "resume root hub%s\n", temp ? "" : " after power loss");
+
+ /* at least some APM implementations will try to deliver
+ * IRQs right away, so delay them until we're ready.
+ */
+ writel(0, &ehci->regs->intr_enable);
+
+ /* re-init operational registers */
+ writel(0, &ehci->regs->segment);
+ writel(ehci->periodic_dma, &ehci->regs->frame_list);
+ writel((u32) ehci->async->qh_dma, &ehci->regs->async_next);