From 7329e211b987a493cbcfca0e98c60eb108ab42df Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Thu, 3 Apr 2008 18:02:56 -0400 Subject: 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 Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hcd.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'drivers/usb/core/hcd.c') diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index f936de75f44..e68fef5361d 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -129,7 +129,7 @@ static const u8 usb2_rh_dev_descriptor [18] = { 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 @@ static int rh_call_control (struct usb_hcd *hcd, struct urb *urb) __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 @@ static int rh_call_control (struct usb_hcd *hcd, struct urb *urb) 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 @@ error: 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 */ -- cgit v1.2.2