USB layer of U-Boot causes USB protocol errors while using USB memory sticks

There are several differences between Linux, Windows and U-boot for initialising the
USB devices. While analysing the behaviour of U-boot it turned out that U-boot does
things really different, and some are wrong (compared to the USB standard).

This patch fixes some errors:
* The NEW_init procedure that was already in the code is good, while the old procedure
  is wrong. See code comments for more info.
* On a Control request the data returned by the device can be more than 8 bytes, while
  the host limits it to 8 bytes. This caused the host to generate a DataOverrun error.
  This results in a lot of USB sticks not being recognised, and the transmission ended
  frequently with a CTL:TIMEOUT Error.
* Added a flag CONFIG_LEGACY_USB_INIT_SEQ to allow users to use the old init procedure.

Signed-off-by: Remy Bohmer <linux@bohmer.net>
Signed-off-by: Markus Klotzbuecher <mk@denx.de>

diff --git a/common/usb.c b/common/usb.c
index be81aaf0bd7061f5606e1c550093ad7b08be2d56..db65d7db34eb481ea6e74cfa49486a65e9ed46e1 100644 (file)
--- a/common/usb.c
+++ b/common/usb.c
@@ -80,7 +80,8 @@ void usb_scan_devices(void);
 
 int usb_hub_probe(struct usb_device *dev, int ifnum);
 void usb_hub_reset(void);
-
+static int hub_port_reset(struct usb_device *dev, int port,
+                         unsigned short *portstat);
 
 /***********************************************************************
  * wait_ms
@@ -765,20 +766,34 @@ int usb_new_device(struct usb_device *dev)
        int tmp;
        unsigned char tmpbuf[USB_BUFSIZ];
 
-       dev->descriptor.bMaxPacketSize0 = 8;  /* Start off at 8 bytes  */
-       dev->maxpacketsize = 0;         /* Default to 8 byte max packet size */
-       dev->epmaxpacketin [0] = 8;
-       dev->epmaxpacketout[0] = 8;
-
        /* We still haven't set the Address yet */
        addr = dev->devnum;
        dev->devnum = 0;
 
-#undef NEW_INIT_SEQ
-#ifdef NEW_INIT_SEQ
+#ifdef CONFIG_LEGACY_USB_INIT_SEQ
+       /* this is the old and known way of initializing devices, it is
+        * different than what Windows and Linux are doing. Windows and Linux
+        * both retrieve 64 bytes while reading the device descriptor
+        * Several USB stick devices report ERR: CTL_TIMEOUT, caused by an
+        * invalid header while reading 8 bytes as device descriptor. */
+       dev->descriptor.bMaxPacketSize0 = 8;        /* Start off at 8 bytes  */
+       dev->maxpacketsize = 0;         /* Default to 8 byte max packet size */
+       dev->epmaxpacketin [0] = 8;
+       dev->epmaxpacketout[0] = 8;
+
+       err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, &dev->descriptor, 8);
+       if (err < 8) {
+               printf("\n      USB device not responding, " \
+                      "giving up (status=%lX)\n",dev->status);
+               return 1;
+       }
+#else
        /* this is a Windows scheme of initialization sequence, with double
-        * reset of the device. Some equipment is said to work only with such
-        * init sequence; this patch is based on the work by Alan Stern:
+        * reset of the device (Linux uses the same sequence, but without double
+        * reset. This double reset is not considered harmful and matches the
+        * Windows behaviour)
+        * Some equipment is said to work only with such init sequence; this
+        * patch is based on the work by Alan Stern:
         * http://sourceforge.net/mailarchive/forum.php?thread_id=5729457&forum_id=5398
         */
        int j;
@@ -790,10 +805,13 @@ int usb_new_device(struct usb_device *dev)
        /* send 64-byte GET-DEVICE-DESCRIPTOR request.  Since the descriptor is
         * only 18 bytes long, this will terminate with a short packet.  But if
         * the maxpacket size is 8 or 16 the device may be waiting to transmit
-        * some more. */
+        * some more, or keeps on retransmitting the 8 byte header. */
 
        desc = (struct usb_device_descriptor *)tmpbuf;
-       desc->bMaxPacketSize0 = 0;
+       dev->descriptor.bMaxPacketSize0 = 64;       /* Start off at 64 bytes  */
+       dev->maxpacketsize = 64;        /* Default to 64 byte max packet size */
+       dev->epmaxpacketin [0] = 64;
+       dev->epmaxpacketout[0] = 64;
        for (j = 0; j < 3; ++j) {
                err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc, 64);
                if (err < 0) {
@@ -824,14 +842,6 @@ int usb_new_device(struct usb_device *dev)
                        return 1;
                }
        }
-#else
-       /* and this is the old and known way of initializing devices */
-       err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, &dev->descriptor, 8);
-       if (err < 8) {
-               printf("\n      USB device not responding, " \
-                       "giving up (status=%lX)\n", dev->status);
-               return 1;
-       }
 #endif
 
        dev->epmaxpacketin [0] = dev->descriptor.bMaxPacketSize0;