USB: fix disconnect bug in cdc-acm

cdc-acm must give up secondary interfaces if the primary is disconnected
and vice versa. This wasn't done correctly.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index ba86fec..93b28ee 100644 (file)
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -838,7 +838,7 @@ static void acm_tty_set_termios(struct tty_struct *tty, struct ktermios *termios
  * USB probe and disconnect routines.
  */
 
-/* Little helper: write buffers free */
+/* Little helpers: write/read buffers free */
 static void acm_write_buffers_free(struct acm *acm)
 {
        int i;
@@ -849,6 +849,15 @@ static void acm_write_buffers_free(struct acm *acm)
        }
 }
 
+static void acm_read_buffers_free(struct acm *acm)
+{
+       struct usb_device *usb_dev = interface_to_usbdev(acm->control);
+       int i, n = acm->rx_buflimit;
+
+       for (i = 0; i < n; i++)
+               usb_buffer_free(usb_dev, acm->readsize, acm->rb[i].base, acm->rb[i].dma);
+}
+
 /* Little helper: write buffers allocate */
 static int acm_write_buffers_alloc(struct acm *acm)
 {
@@ -1171,8 +1180,7 @@ alloc_fail8:
        for (i = 0; i < ACM_NW; i++)
                usb_free_urb(acm->wb[i].urb);
 alloc_fail7:
-       for (i = 0; i < num_rx_buf; i++)
-               usb_buffer_free(usb_dev, acm->readsize, acm->rb[i].base, acm->rb[i].dma);
+       acm_read_buffers_free(acm);
        for (i = 0; i < num_rx_buf; i++)
                usb_free_urb(acm->ru[i].urb);
        usb_free_urb(acm->ctrlurb);
@@ -1209,15 +1217,9 @@ static void acm_disconnect(struct usb_interface *intf)
 {
        struct acm *acm = usb_get_intfdata(intf);
        struct usb_device *usb_dev = interface_to_usbdev(intf);
-       int i;
-
-       if (!acm || !acm->dev) {
-               dbg("disconnect on nonexisting interface");
-               return;
-       }
 
        mutex_lock(&open_mutex);
-       if (!usb_get_intfdata(intf)) {
+       if (!acm || !acm->dev) {
                mutex_unlock(&open_mutex);
                return;
        }
@@ -1236,10 +1238,10 @@ static void acm_disconnect(struct usb_interface *intf)
 
        acm_write_buffers_free(acm);
        usb_buffer_free(usb_dev, acm->ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
-       for (i = 0; i < acm->rx_buflimit; i++)
-               usb_buffer_free(usb_dev, acm->readsize, acm->rb[i].base, acm->rb[i].dma);
+       acm_read_buffers_free(acm);
 
-       usb_driver_release_interface(&acm_driver, intf == acm->control ? acm->data : intf);
+       usb_driver_release_interface(&acm_driver, intf == acm->control ?
+                                       acm->data : acm->control);
 
        if (!acm->used) {
                acm_tty_unregister(acm);