usb: cdc-acm: Decrement tty port's refcount if probe() fail

The cdc-acm driver does not have a refcount of itself, but uses a
tty_port's refcount. That is, if the refcount of tty_port is '0', we
can clean up the cdc-acm driver by calling the .destruct()
callback function of struct tty_port_operations.

The problem is the destruct() callback function is not called if
the probe() fails, because tty_port's refcount is not zero. So,
add tty_port_put() when probe() fails.

Signed-off-by: Jaejoong Kim <climbbb.kim@gmail.com>
Acked-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 7b366a6..ed0475c 100644 (file)
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -1378,6 +1378,9 @@ made_compressed_probe:
        if (acm == NULL)
                goto alloc_fail;
 
+       tty_port_init(&acm->port);
+       acm->port.ops = &acm_port_ops;
+
        minor = acm_alloc_minor(acm);
        if (minor < 0)
                goto alloc_fail1;
@@ -1413,22 +1416,20 @@ made_compressed_probe:
                acm->out = usb_sndintpipe(usb_dev, epwrite->bEndpointAddress);
        else
                acm->out = usb_sndbulkpipe(usb_dev, epwrite->bEndpointAddress);
-       tty_port_init(&acm->port);
-       acm->port.ops = &acm_port_ops;
        init_usb_anchor(&acm->delayed);
        acm->quirks = quirks;
 
        buf = usb_alloc_coherent(usb_dev, ctrlsize, GFP_KERNEL, &acm->ctrl_dma);
        if (!buf)
-               goto alloc_fail2;
+               goto alloc_fail1;
        acm->ctrl_buffer = buf;
 
        if (acm_write_buffers_alloc(acm) < 0)
-               goto alloc_fail4;
+               goto alloc_fail2;
 
        acm->ctrlurb = usb_alloc_urb(0, GFP_KERNEL);
        if (!acm->ctrlurb)
-               goto alloc_fail5;
+               goto alloc_fail3;
 
        for (i = 0; i < num_rx_buf; i++) {
                struct acm_rb *rb = &(acm->read_buffers[i]);
@@ -1437,13 +1438,13 @@ made_compressed_probe:
                rb->base = usb_alloc_coherent(acm->dev, readsize, GFP_KERNEL,
                                                                &rb->dma);
                if (!rb->base)
-                       goto alloc_fail6;
+                       goto alloc_fail4;
                rb->index = i;
                rb->instance = acm;
 
                urb = usb_alloc_urb(0, GFP_KERNEL);
                if (!urb)
-                       goto alloc_fail6;
+                       goto alloc_fail4;
 
                urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
                urb->transfer_dma = rb->dma;
@@ -1465,7 +1466,7 @@ made_compressed_probe:
 
                snd->urb = usb_alloc_urb(0, GFP_KERNEL);
                if (snd->urb == NULL)
-                       goto alloc_fail7;
+                       goto alloc_fail5;
 
                if (usb_endpoint_xfer_int(epwrite))
                        usb_fill_int_urb(snd->urb, usb_dev, acm->out,
@@ -1483,7 +1484,7 @@ made_compressed_probe:
 
        i = device_create_file(&intf->dev, &dev_attr_bmCapabilities);
        if (i < 0)
-               goto alloc_fail7;
+               goto alloc_fail5;
 
        if (h.usb_cdc_country_functional_desc) { /* export the country data */
                struct usb_cdc_country_functional_desc * cfd =
@@ -1542,7 +1543,7 @@ skip_countries:
                        &control_interface->dev);
        if (IS_ERR(tty_dev)) {
                rv = PTR_ERR(tty_dev);
-               goto alloc_fail8;
+               goto alloc_fail6;
        }
 
        if (quirks & CLEAR_HALT_CONDITIONS) {
@@ -1551,7 +1552,7 @@ skip_countries:
        }
 
        return 0;
-alloc_fail8:
+alloc_fail6:
        if (acm->country_codes) {
                device_remove_file(&acm->control->dev,
                                &dev_attr_wCountryCodes);
@@ -1560,23 +1561,21 @@ alloc_fail8:
                kfree(acm->country_codes);
        }
        device_remove_file(&acm->control->dev, &dev_attr_bmCapabilities);
-alloc_fail7:
+alloc_fail5:
        usb_set_intfdata(intf, NULL);
        for (i = 0; i < ACM_NW; i++)
                usb_free_urb(acm->wb[i].urb);
-alloc_fail6:
+alloc_fail4:
        for (i = 0; i < num_rx_buf; i++)
                usb_free_urb(acm->read_urbs[i]);
        acm_read_buffers_free(acm);
        usb_free_urb(acm->ctrlurb);
-alloc_fail5:
+alloc_fail3:
        acm_write_buffers_free(acm);
-alloc_fail4:
-       usb_free_coherent(usb_dev, ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
 alloc_fail2:
-       acm_release_minor(acm);
+       usb_free_coherent(usb_dev, ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
 alloc_fail1:
-       kfree(acm);
+       tty_port_put(&acm->port);
 alloc_fail:
        return rv;
 }