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path: root/drivers/usb/host/ohci-ppc-of.c
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Diffstat (limited to 'drivers/usb/host/ohci-ppc-of.c')
-rw-r--r--drivers/usb/host/ohci-ppc-of.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/usb/host/ohci-ppc-of.c b/drivers/usb/host/ohci-ppc-of.c
index 7ac53264ead..68a30171029 100644
--- a/drivers/usb/host/ohci-ppc-of.c
+++ b/drivers/usb/host/ohci-ppc-of.c
@@ -91,6 +91,7 @@ ohci_hcd_ppc_of_probe(struct of_device *op, const struct of_device_id *match)
int rv;
int is_bigendian;
+ struct device_node *np;
if (usb_disabled())
return -ENODEV;
@@ -147,6 +148,30 @@ ohci_hcd_ppc_of_probe(struct of_device *op, const struct of_device_id *match)
if (rv == 0)
return 0;
+ /* by now, 440epx is known to show usb_23 erratum */
+ np = of_find_compatible_node(NULL, NULL, "ibm,usb-ehci-440epx");
+
+ /* Work around - At this point ohci_run has executed, the
+ * controller is running, everything, the root ports, etc., is
+ * set up. If the ehci driver is loaded, put the ohci core in
+ * the suspended state. The ehci driver will bring it out of
+ * suspended state when / if a non-high speed USB device is
+ * attached to the USB Host port. If the ehci driver is not
+ * loaded, do nothing. request_mem_region is used to test if
+ * the ehci driver is loaded.
+ */
+ if (np != NULL) {
+ if (!of_address_to_resource(np, 0, &res)) {
+ if (!request_mem_region(res.start, 0x4, hcd_name)) {
+ writel_be((readl_be(&ohci->regs->control) |
+ OHCI_USB_SUSPEND), &ohci->regs->control);
+ (void) readl_be(&ohci->regs->control);
+ } else
+ release_mem_region(res.start, 0x4);
+ } else
+ pr_debug(__FILE__ ": cannot get ehci offset from fdt\n");
+ }
+
iounmap(hcd->regs);
err_ioremap:
irq_dispose_mapping(irq);