usb: ehci: prevent bad PORTSC register access

1. The 'index' of ehci_submit_root() is not always > 0.

   e.g.
   While it gets invoked from usb_get_descriptor(),
   the 'index' is always a '0'. (See ch.9 of USB2.0)

2. The PORTSC register is not always required, and thus it
   should only report a port error when necessary.
   It would cause a port scan failure if the ehci_submit_root()
   always gets terminated by a port error.

Signed-off-by: Kuo-Jung Su <dantesu@faraday-tech.com>
CC: Marek Vasut <marex@denx.de>

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 445759b9ac1aed2429ea439f14b23c99f4e15ed3..443cc2313465fcc872f21fbca52914a9bf50c2f2 100644 (file)
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -616,11 +616,6 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
        int port = le16_to_cpu(req->index) & 0xff;
        struct ehci_ctrl *ctrl = dev->controller;
 
-       if (port > CONFIG_SYS_USB_EHCI_MAX_ROOT_PORTS) {
-               printf("The request port(%d) is not configured\n", port - 1);
-               return -1;
-       }
-       status_reg = (uint32_t *)&ctrl->hcor->or_portsc[port - 1];
        srclen = 0;
 
        debug("req=%u (%#x), type=%u (%#x), value=%u, index=%u\n",
@@ -630,6 +625,21 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
 
        typeReq = req->request | req->requesttype << 8;
 
+       switch (typeReq) {
+       case USB_REQ_GET_STATUS | ((USB_RT_PORT | USB_DIR_IN) << 8):
+       case USB_REQ_SET_FEATURE | ((USB_DIR_OUT | USB_RT_PORT) << 8):
+       case USB_REQ_CLEAR_FEATURE | ((USB_DIR_OUT | USB_RT_PORT) << 8):
+               if (!port || port > CONFIG_SYS_USB_EHCI_MAX_ROOT_PORTS) {
+                       printf("The request port(%d) is not configured\n", port - 1);
+                       return -1;
+               }
+               status_reg = (uint32_t *)&ctrl->hcor->or_portsc[port - 1];
+               break;
+       default:
+               status_reg = NULL;
+               break;
+       }
+
        switch (typeReq) {
        case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
                switch (le16_to_cpu(req->value) >> 8) {