Changeset 3f2af64 in mainline

Timestamp:

2011-04-10T14:08:12Z (14 years ago)

Author:

Vojtech Horky <vojtechhorky@…>

Branches:

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

Children:

4776ba9, d8b275d

Parents:

231748a

Message:

libusb: refactoring

File:

• uspace/lib/usb/src/devdrv.c (modified) (7 diffs)

uspace/lib/usb/src/devdrv.c ¶

@@ -180 +180 @@
  * with usb_pipe_initialize_from_configuration().
  *
+ * @warning This is a wrapper function that does several operations that
+ * can fail and that cannot be rollbacked easily. That means that a failure
+ * during the SET_INTERFACE request would result in having a device with
+ * no pipes at all (except the default control one). That is because the old
+ * pipes needs to be unregistered at HC first and the new ones could not
+ * be created.
+ *
  * @param dev USB device.
  * @param alternate_setting Alternate setting to choose.
@@ -193 +200 @@
 
         int rc;
-
-        /* TODO: more transactional behavior. */
 
         /* Destroy existing pipes. */
@@ -431 +436 @@
 }
 
-/** Initialize control pipe and device descriptors. */
-static int initialize_ctrl_pipe_and_descriptors(usb_device_t *dev,
-     const char **errmsg)
+/** Initialize control pipe in a device.
+ *
+ * @param dev USB device in question.
+ * @param errmsg Where to store error context.
+ * @return
+ */
+static int init_wire_and_ctrl_pipe(usb_device_t *dev, const char **errmsg)
 {
         int rc;
@@ -451 +460 @@
         }
 
-        /* Get our interface. */
-        dev->interface_no = usb_device_get_assigned_interface(dev->ddf_dev);
-
-        /* Retrieve the descriptors. */
-        rc = usb_device_retrieve_descriptors(&dev->ctrl_pipe,
-            &dev->descriptors);
-        if (rc != EOK) {
-                *errmsg = "descriptor retrieval";
-        }
-
-        return rc;
+        return EOK;
 }
 
@@ -489 +488 @@
         }
 
+        // FIXME: proper deallocation in case of errors
+
         dev->ddf_dev = ddf_dev;
         dev->driver_data = NULL;
@@ -497 +498 @@
         dev->pipes = NULL;
 
-        rc = initialize_ctrl_pipe_and_descriptors(dev, errstr_ptr);
-        if (rc != EOK) {
-                return rc;
-        }
-
+        /* Initialize backing wire and control pipe. */
+        rc = init_wire_and_ctrl_pipe(dev, errstr_ptr);
+        if (rc != EOK) {
+                return rc;
+        }
+
+        /* Get our interface. */
+        dev->interface_no = usb_device_get_assigned_interface(dev->ddf_dev);
+
+        /* Retrieve standard descriptors. */
+        rc = usb_device_retrieve_descriptors(&dev->ctrl_pipe,
+            &dev->descriptors);
+        if (rc != EOK) {
+                *errstr_ptr = "descriptor retrieval";
+                return rc;
+        }
+
+        /* Create alternate interfaces. */
         rc = usb_alternate_interfaces_create(dev->descriptors.configuration,
             dev->descriptors.configuration_size, dev->interface_no,
@@ -513 +527 @@
         if (rc != EOK) {
                 *errstr_ptr = "pipes initialization";
-                /* TODO: deallocate */
                 return rc;
         }