+static void __devinit ehci_bios_handoff(struct pci_dev *pdev,
+ void __iomem *op_reg_base,
+ u32 cap, u8 offset)
+{
+ int msec, tried_handoff = 0;
+
+ if (cap & EHCI_USBLEGSUP_BIOS) {
+ dev_dbg(&pdev->dev, "EHCI: BIOS handoff\n");
+
+#if 0
+/* aleksey_gorelov@phoenix.com reports that some systems need SMI forced on,
+ * but that seems dubious in general (the BIOS left it off intentionally)
+ * and is known to prevent some systems from booting. so we won't do this
+ * unless maybe we can determine when we're on a system that needs SMI forced.
+ */
+ /* BIOS workaround (?): be sure the pre-Linux code
+ * receives the SMI
+ */
+ pci_read_config_dword(pdev, offset + EHCI_USBLEGCTLSTS, &val);
+ pci_write_config_dword(pdev, offset + EHCI_USBLEGCTLSTS,
+ val | EHCI_USBLEGCTLSTS_SOOE);
+#endif
+
+ /* some systems get upset if this semaphore is
+ * set for any other reason than forcing a BIOS
+ * handoff..
+ */
+ pci_write_config_byte(pdev, offset + 3, 1);
+ }
+
+ /* if boot firmware now owns EHCI, spin till it hands it over. */
+ msec = 1000;
+ while ((cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) {
+ tried_handoff = 1;
+ msleep(10);
+ msec -= 10;
+ pci_read_config_dword(pdev, offset, &cap);
+ }
+
+ if (cap & EHCI_USBLEGSUP_BIOS) {
+ /* well, possibly buggy BIOS... try to shut it down,
+ * and hope nothing goes too wrong
+ */
+ dev_warn(&pdev->dev, "EHCI: BIOS handoff failed"
+ " (BIOS bug?) %08x\n", cap);
+ pci_write_config_byte(pdev, offset + 2, 0);
+ }
+
+ /* just in case, always disable EHCI SMIs */
+ pci_write_config_dword(pdev, offset + EHCI_USBLEGCTLSTS, 0);
+
+ /* If the BIOS ever owned the controller then we can't expect
+ * any power sessions to remain intact.
+ */
+ if (tried_handoff)
+ writel(0, op_reg_base + EHCI_CONFIGFLAG);
+}
+