USB: root hubs don't lie about their number of TTs
Currently EHCI root hubs enumerate with a bDeviceProtocol code
indicating that they possess a Transaction Translator. However the
vast majority of controllers do not; they rely on a companion
controller to handle full- and low-speed communications. This patch
(as1064) changes the root-hub device descriptor to match the actual
situation.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index f936de7..e68fef5 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -129,7 +129,7 @@
0x09, /* __u8 bDeviceClass; HUB_CLASSCODE */
0x00, /* __u8 bDeviceSubClass; */
- 0x01, /* __u8 bDeviceProtocol; [ usb 2.0 single TT ]*/
+ 0x00, /* __u8 bDeviceProtocol; [ usb 2.0 no TT ] */
0x40, /* __u8 bMaxPacketSize0; 64 Bytes */
0x6b, 0x1d, /* __le16 idVendor; Linux Foundation */
@@ -354,9 +354,10 @@
__attribute__((aligned(4)));
const u8 *bufp = tbuf;
int len = 0;
- int patch_wakeup = 0;
int status;
int n;
+ u8 patch_wakeup = 0;
+ u8 patch_protocol = 0;
might_sleep();
@@ -433,6 +434,8 @@
else
goto error;
len = 18;
+ if (hcd->has_tt)
+ patch_protocol = 1;
break;
case USB_DT_CONFIG << 8:
if (hcd->driver->flags & HCD_USB2) {
@@ -527,6 +530,13 @@
bmAttributes))
((struct usb_config_descriptor *)ubuf)->bmAttributes
|= USB_CONFIG_ATT_WAKEUP;
+
+ /* report whether RH hardware has an integrated TT */
+ if (patch_protocol &&
+ len > offsetof(struct usb_device_descriptor,
+ bDeviceProtocol))
+ ((struct usb_device_descriptor *) ubuf)->
+ bDeviceProtocol = 1;
}
/* any errors get returned through the urb completion */