V4L/DVB (9266): videobuf: properly handle attachment failure

This fixes attachment failure where we now unwind
attachment and skip non-attached nodes where
necessary so we can survive a fault situation
correctly.

Signed-off-by: Darron Broad <darron@kewl.org>
Signed-off-by: Steven Toth <stoth@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 24 insertions, 13 deletions

diff --git a/drivers/media/video/videobuf-dvb.c b/drivers/media/video/videobuf-dvb.c
index fc4cfaa7bf5f..7c74845af267 100644
--- a/drivers/media/video/videobuf-dvb.c
+++ b/drivers/media/video/videobuf-dvb.c
@@ -145,19 +145,19 @@ int videobuf_dvb_register_bus(struct videobuf_dvb_frontends *f,
 {
         struct list_head *list, *q;
         struct videobuf_dvb_frontend *fe;
-        int res = -EINVAL;
+        int res;
 
         fe = videobuf_dvb_get_frontend(f, 1);
         if (!fe) {
                 printk(KERN_WARNING "Unable to register the adapter which has no frontends\n");
-                goto err;
+                return -EINVAL;
         }
 
         /* Bring up the adapter */
         res = videobuf_dvb_register_adapter(f, module, adapter_priv, device, fe->dvb.name, adapter_nr, mfe_shared);
         if (res < 0) {
                 printk(KERN_WARNING "videobuf_dvb_register_adapter failed (errno = %d)\n", res);
-                goto err;
+                return res;
         }
 
         /* Attach all of the frontends to the adapter */
@@ -168,11 +168,15 @@ int videobuf_dvb_register_bus(struct videobuf_dvb_frontends *f,
                 if (res < 0) {
                         printk(KERN_WARNING "%s: videobuf_dvb_register_frontend failed (errno = %d)\n",
                                 fe->dvb.name, res);
+                        goto err;
                 }
         }
         mutex_unlock(&f->lock);
+        return 0;
 
 err:
+        mutex_unlock(&f->lock);
+        videobuf_dvb_unregister_bus(f);
         return res;
 }
 
@@ -264,6 +268,10 @@ int videobuf_dvb_register_frontend(struct dvb_adapter *adapter, struct videobuf_
 
         /* register network adapter */
         dvb_net_init(adapter, &dvb->net, &dvb->demux.dmx);
+        if (dvb->net.dvbdev == NULL) {
+                result = -ENOMEM;
+                goto fail_fe_conn;
+        }
         return 0;
 
 fail_fe_conn:
@@ -278,7 +286,7 @@ fail_dmx:
         dvb_unregister_frontend(dvb->frontend);
 fail_frontend:
         dvb_frontend_detach(dvb->frontend);
-        dvb_unregister_adapter(adapter);
+        dvb->frontend = NULL;
 
         return result;
 }
@@ -291,15 +299,18 @@ void videobuf_dvb_unregister_bus(struct videobuf_dvb_frontends *f)
         mutex_lock(&f->lock);
         list_for_each_safe(list, q, &f->felist) {
                 fe = list_entry(list, struct videobuf_dvb_frontend, felist);
-
-                dvb_net_release(&fe->dvb.net);
-                fe->dvb.demux.dmx.remove_frontend(&fe->dvb.demux.dmx, &fe->dvb.fe_mem);
-                fe->dvb.demux.dmx.remove_frontend(&fe->dvb.demux.dmx, &fe->dvb.fe_hw);
-                dvb_dmxdev_release(&fe->dvb.dmxdev);
-                dvb_dmx_release(&fe->dvb.demux);
-                dvb_unregister_frontend(fe->dvb.frontend);
-                dvb_frontend_detach(fe->dvb.frontend);
-
+                if(fe->dvb.net.dvbdev) {
+                        dvb_net_release(&fe->dvb.net);
+                        fe->dvb.demux.dmx.remove_frontend(&fe->dvb.demux.dmx, &fe->dvb.fe_mem);
+                        fe->dvb.demux.dmx.remove_frontend(&fe->dvb.demux.dmx, &fe->dvb.fe_hw);
+                        dvb_dmxdev_release(&fe->dvb.dmxdev);
+                        dvb_dmx_release(&fe->dvb.demux);
+                        dvb_unregister_frontend(fe->dvb.frontend);
+                }
+                if(fe->dvb.frontend) {  /* always allocated, may have been reset */
+                        dvb_frontend_detach(fe->dvb.frontend);
+                        fe->dvb.frontend = NULL;
+                }
                 list_del(list);
                 kfree(fe);
         }