Changeset 4cbb6e4 in mainline

Timestamp:

2011-09-13T12:46:03Z (13 years ago)

Author:

Jan Vesely <jano.vesely@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

3a8370c

Parents:

a837544

Message:

libusbhost: Don't include direction in endpoint hash, make BIDIRECTIONAL match both directions.

This servers dual purpose:
1) Prevents registering IN and OUT endpoints if there already is a BIDIRECTIONAL endpoint with the same address and number
2) BIDIRECTIONAL endpoints are found when searching for any direction, thus control transfers don't need special handling in batch preparation.

File:

• uspace/lib/usbhost/src/usb_endpoint_manager.c (modified) (2 diffs)

uspace/lib/usbhost/src/usb_endpoint_manager.c

@@ -45 +45 @@
 static hash_index_t node_hash(unsigned long key[])
 {
-        hash_index_t hash = 0;
-        unsigned i = 0;
-        for (;i < MAX_KEYS; ++i) {
-                hash ^= key[i];
-        }
-        hash %= BUCKET_COUNT;
-        return hash;
+        /* USB endpoints use 4 bits, thus ((key[0] << 4) | key[1])
+         * produces unique value for every address.endpoint pair */
+        return ((key[0] << 4) | key[1]) % BUCKET_COUNT;
 }
 /*----------------------------------------------------------------------------*/
@@ -63 +59 @@
         switch (keys) {
         case 3:
-                match = match && (key[2] == node->ep->direction);
+                match = match &&
+                    ((key[2] == node->ep->direction)
+                    || (node->ep->direction == USB_DIRECTION_BOTH));
         case 2:
                 match = match && (key[1] == (unsigned long)node->ep->endpoint);