On Fri, 8 Oct 2004, martin f krafft wrote:
> > Sometimes errors like this and the ones above are just temporary.
> > The device takes a moment to warm up and start working right. You
> > only need to worry about it if the device doesn't work in the end.
>
> I do have another device (a USB servo controller) which gives the
> same messages and does not work at all. USB on the machine is fine
> though. Thus, may I conclude that the device firmware is whacked?
No, not necessarily. A lot of devices seem to be having these problems,
and many of them work okay under 2.4. I don't know what the real reason
for the problem is -- although I assume that a truly _correctly_ working
device wouldn't have any difficulties.
> > I found the reason for your oops. It has already been fixed in the USB
> > development kernel but the fix isn't in 2.6.9-rc3. It's the first patch
> > below.
>
> Superb. I will try 2.6.9-rc3 then.
No -- I said the fix _isn't_ in 2.6.9-rc3.
> But first I will try 2.6.8.1 with the two patches. Might be
> a couple of days.
The patches I sent were for 2.6.9-rc3. The first one might work all right
2.6.8.1 but the second one definitely won't. Below is a version of the
second patch for 2.6.8.1.
Alan Stern
--- 2.6.8.1/drivers/usb/core/hub.c.orig 2004-10-04 15:39:26.000000000 -0400
+++ 2.6.8.1/drivers/usb/core/hub.c 2004-10-07 14:10:32.000000000 -0400
@@ -1127,7 +1127,7 @@
#define PORT_RESET_TRIES 5
#define SET_ADDRESS_TRIES 2
#define GET_DESCRIPTOR_TRIES 2
-#define SET_CONFIG_TRIES 2
+#define SET_CONFIG_TRIES 4
#define HUB_ROOT_RESET_TIME 50 /* times are in msec */
#define HUB_SHORT_RESET_TIME 10
@@ -1352,7 +1352,8 @@
* pointers, it's not necessary to lock the device.
*/
static int
-hub_port_init (struct usb_device *hdev, struct usb_device *udev, int port)
+hub_port_init (struct usb_device *hdev, struct usb_device *udev, int port,
+ int get_descriptor_first)
{
static DECLARE_MUTEX(usb_address0_sem);
@@ -1387,6 +1388,7 @@
dev_dbg(&udev->dev, "device reset changed speed!\n");
goto fail;
}
+ oldspeed = udev->speed;
/* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
* it's fixed size except for full speed devices.
@@ -1396,19 +1398,18 @@
i = 64;
break;
case USB_SPEED_FULL: /* 8, 16, 32, or 64 */
- /* to determine the ep0 maxpacket size, read the first 8
- * bytes from the device descriptor to get bMaxPacketSize0;
- * then correct our initial (small) guess.
+ /* to determine the ep0 maxpacket size, try to read
+ * the device descriptor to get bMaxPacketSize0 and
+ * then correct our initial guess.
*/
- // FALLTHROUGH
+ i = 64;
+ break;
case USB_SPEED_LOW: /* fixed at 8 */
i = 8;
break;
default:
goto fail;
}
- udev->epmaxpacketin [0] = i;
- udev->epmaxpacketout[0] = i;
dev_info (&udev->dev,
"%s %s speed USB device using address %d\n",
@@ -1433,17 +1434,63 @@
udev->tt = &hub->tt;
udev->ttport = port + 1;
}
+
+ /* Clear out any stale HC state pertaining to device 0 endpoint 0 */
+ j = udev->devnum;
+ udev->devnum = 0;
+ usb_disable_endpoint(udev, 0 + USB_DIR_IN);
+ usb_disable_endpoint(udev, 0 + USB_DIR_OUT);
+ udev->devnum = j;
+ udev->epmaxpacketin [0] = i;
+ udev->epmaxpacketout[0] = i;
+ usb_endpoint_running(udev, 0, 0);
+ usb_endpoint_running(udev, 0, 1);
/* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
* Because device hardware and firmware is sometimes buggy in
* this area, and this is how Linux has done it for ages.
* Change it cautiously.
*
- * NOTE: Windows gets the descriptor first, seemingly to help
- * work around device bugs like "can't use addresses with bit 3
- * set in certain configurations". Yes, really.
+ * NOTE: For full-speed devices, if get_descriptor_first
+ * is set we will start by issuing a 64-byte GET_DESCRIPTOR
+ * request. This is what Windows does, so it may help with some
+ * non-standards-compliant devices. Otherwise we start with
+ * SET_ADDRESS and then try to read the first 8 bytes of the
+ * device descriptor to get the ep0 maxpacket value.
*/
- for (i = 0; i < GET_DESCRIPTOR_TRIES; ++i) {
+ for (i = 0; i < GET_DESCRIPTOR_TRIES; (++i, msleep(100))) {
+ if (get_descriptor_first) {
+ struct usb_device_descriptor *buf;
+
+ buf = kmalloc(64, GFP_NOIO);
+ if (!buf) {
+ retval = -ENOMEM;
+ continue;
+ }
+ memset(buf, 0, 64);
+ j = usb_control_msg(udev,
+ /* Address 0 */
+ (PIPE_CONTROL << 30) | USB_DIR_IN,
+ USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
+ USB_DT_DEVICE << 8, 0,
+ buf, 64,
+ HZ * USB_CTRL_GET_TIMEOUT);
+ udev->descriptor = *buf;
+ kfree(buf);
+
+ retval = hub_port_reset(hdev, port, udev, delay);
+ if (retval < 0) /* error or disconnect */
+ goto fail;
+ if (oldspeed != udev->speed) {
+ retval = -ENODEV;
+ goto fail;
+ }
+ if (udev->descriptor.bMaxPacketSize0 < 8) {
+ retval = -EMSGSIZE;
+ continue;
+ }
+ }
+
for (j = 0; j < SET_ADDRESS_TRIES; ++j) {
retval = hub_set_address(udev);
if (retval >= 0)
@@ -1462,10 +1511,12 @@
* - read ep0 maxpacket even for high and low speed,
*/
msleep(10);
- retval = usb_get_device_descriptor(udev, 8);
+ if (get_descriptor_first)
+ retval = 8;
+ else
+ retval = usb_get_device_descriptor(udev, 8);
if (retval >= 8)
break;
- msleep(100);
}
if (retval != 8) {
dev_err(&udev->dev, "device descriptor read/%s, error %d\n",
@@ -1645,7 +1696,7 @@
}
/* reset and get descriptor */
- status = hub_port_init(hdev, udev, port);
+ status = hub_port_init(hdev, udev, port, (i < 2));
if (status < 0)
goto loop;
@@ -2060,7 +2111,7 @@
{
struct usb_device *parent = udev->parent;
struct usb_device_descriptor descriptor = udev->descriptor;
- int i, ret, port = -1;
+ int i, ret = 0, port = -1;
struct usb_hub *hub;
if (udev->state == USB_STATE_NOTATTACHED ||
@@ -2092,7 +2143,11 @@
return -ENOENT;
}
- ret = hub_port_init(parent, udev, port);
+ for (i = 0; i < SET_CONFIG_TRIES; ++i) {
+ ret = hub_port_init(parent, udev, port, (i < 2));
+ if (ret >= 0)
+ break;
+ }
if (ret < 0)
goto re_enumerate;
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