From 79dc404f011ecf6f1b9bc926f94c399b967f7354 Mon Sep 17 00:00:00 2001
From: libdlo <libdlo@displaylink.com>
Date: Thu, 14 May 2009 15:08:44 -0700
Subject: Make all DL auto-install and composite devices work And make programs
 using libdlo that are run != sudo, fail gracefully

---
 src/dlo_usb.c | 49 ++++++++++++++++++++++++++++---------------------
 1 file changed, 28 insertions(+), 21 deletions(-)

diff --git a/src/dlo_usb.c b/src/dlo_usb.c
index e28f803..a2e1bf1 100644
--- a/src/dlo_usb.c
+++ b/src/dlo_usb.c
@@ -268,9 +268,12 @@ static dlo_retcode_t check_device(struct usb_device *udev)
 
 error:
   /* Free our dev->cnct USB information structure */
-  if (dev->cnct)
-    dlo_free(dev->cnct);
-  dev->cnct = NULL;
+  if (dev)
+  {
+    if (dev->cnct)
+      dlo_free(dev->cnct);
+    dev->cnct = NULL;
+  }
 
   /* Close our temporary handle for the device */
   (void) usb_close(uhand);
@@ -289,8 +292,9 @@ dlo_retcode_t dlo_usb_open(dlo_device_t * const dev)
 {
   dlo_retcode_t   err;
   usb_dev_handle *uhand;
-  char*		 driver_name;
+  char*		  driver_name;
   int             usb_configuration;
+  int             i;
   int32_t         db = usb_find_busses();
   int32_t         dd = usb_find_devices();
 
@@ -300,7 +304,7 @@ dlo_retcode_t dlo_usb_open(dlo_device_t * const dev)
 
   /* Open the device */
   uhand = usb_open(dev->cnct->udev);
-  //DPRINTF("usb: open: uhand &%X\n", (int)uhand);
+  DPRINTF("usb: open: uhand &%X\n", (int)uhand);
 
   if (!uhand)
     return dlo_err_open;
@@ -314,30 +318,33 @@ dlo_retcode_t dlo_usb_open(dlo_device_t * const dev)
   /*
    * Because some displaylink devices may report 
    * a class code (like HID or MSC) that gets
-   * matched by a kernel driver, must detach
+   * matched by a kernel driver, we must detach
    * those drivers before libusb can successfully
-   * set configuration or talk to those devices
-   * unfortunately, this call returns error
-   * even if successful
-   /
+   * set configuration or talk to those devices.
+   * For now, we kick everyone off our device, 
+   * but that includes cases we're intentionally
+   * a composite device with HID interfaces that
+   * control something (e.g. a button on a dock).
+   * And the code below is blindly unloading
+   * the kernel HID drivers for those.  May want
+   * to get more sophisticated in the future.
+   */
   driver_name = dlo_malloc(128);
-  if (!usb_get_driver_np(uhand, 0, driver_name, 128))
+  for (i=0; i < dev->cnct->udev->config->bNumInterfaces; i++) 
   {
-    DPRINTF("usb: driver (%s) already attached to device\n", driver_name);
-    usb_detach_kernel_driver_np(uhand,0);
+    memset(driver_name, 0, 128);
+    if (usb_get_driver_np(uhand, i, driver_name, 128) == 0)
+    {
+      DPRINTF("usb: driver (%s) already attached to device\n", driver_name);
+
+      // Reports are that this call can return error even if successful
+      usb_detach_kernel_driver_np(uhand,i);
+    }
   }
    
-  /* set configuration fails on composite devices. 
-   * We could set configuration
-   * only when necessary, but that's just a partial 
-   * mitigation. TODO: Need fuller solution.
-   */
-  //usb_configuration = usb_get_configuration(uhand);
-  //if (usb_configuration != 1) 
   UERR(usb_set_configuration(uhand, 1));
 
   //DPRINTF("usb: open: claiming iface...\n");
-  // TODO: shouldn't assume iface 0
   UERR(usb_claim_interface(uhand, 0));
 
   /* Mark the device as claimed */
-- 
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