[media] dvb_usb_v2: do not release USB interface when device reconnects

USB core will call disconnect and remove driver for us as device
will disconnect itself. After that it is loaded again as a new
device but it is warm and no firmware loading needed.

Reported-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 16 insertions, 4 deletions

diff --git a/drivers/media/dvb/dvb-usb/dvb_usb_init.c b/drivers/media/dvb/dvb-usb/dvb_usb_init.c
index 0ac1a72a7d81..e9bb006bb725 100644
--- a/drivers/media/dvb/dvb-usb/dvb_usb_init.c
+++ b/drivers/media/dvb/dvb-usb/dvb_usb_init.c
@@ -431,11 +431,24 @@ static void dvb_usbv2_init_work(struct work_struct *work)
                                 KBUILD_MODNAME, d->name);
                 ret = dvb_usbv2_download_firmware(d);
                 if (ret == 0) {
+                        /* device is warm, continue initialization */
                         ;
                 } else if (ret == RECONNECTS_USB) {
-                        ret = 0;
-                        goto exit_usb_driver_release_interface;
+                        /*
+                         * USB core will call disconnect() and then probe()
+                         * as device reconnects itself from the USB bus.
+                         * disconnect() will release all driver resources
+                         * and probe() is called for 'new' device. As 'new'
+                         * device is warm we should never go here again.
+                         */
+                        return;
                 } else {
+                        /* Unexpected fatal error. We must unregister driver
+                         * manually from the device, because device is already
+                         * register by returning from probe() with success.
+                         * usb_driver_release_interface() finally calls
+                         * disconnect() in order to free resources.
+                         */
                         goto err_usb_driver_release_interface;
                 }
         }
@@ -453,8 +466,7 @@ static void dvb_usbv2_init_work(struct work_struct *work)
 err_usb_driver_release_interface:
         pr_info("%s: '%s' error while loading driver (%d)\n", KBUILD_MODNAME,
                         d->name, ret);
-exit_usb_driver_release_interface:
-        /* it finally calls .disconnect() which frees mem */
+        /* it finally calls disconnect() which frees mem */
         usb_driver_release_interface(to_usb_driver(d->intf->dev.driver),
                         d->intf);
         pr_debug("%s: failed=%d\n", __func__, ret);