3 files changed, 49 insertions, 1 deletions

diff --git a/drivers/media/dvb/dvb-core/dvb_frontend.c b/drivers/media/dvb/dvb-core/dvb_frontend.c
index 26671757c70b..62696f865576 100644
--- a/drivers/media/dvb/dvb-core/dvb_frontend.c
+++ b/drivers/media/dvb/dvb-core/dvb_frontend.c
@@ -47,6 +47,7 @@ static int dvb_shutdown_timeout;
 static int dvb_force_auto_inversion;
 static int dvb_override_tune_delay;
 static int dvb_powerdown_on_sleep = 1;
+static int dvb_mfe_wait_time = 5;
 
 module_param_named(frontend_debug, dvb_frontend_debug, int, 0644);
 MODULE_PARM_DESC(frontend_debug, "Turn on/off frontend core debugging (default:off).");
@@ -58,6 +59,8 @@ module_param(dvb_override_tune_delay, int, 0644);
 MODULE_PARM_DESC(dvb_override_tune_delay, "0: normal (default), >0 => delay in milliseconds to wait for lock after a tune attempt");
 module_param(dvb_powerdown_on_sleep, int, 0644);
 MODULE_PARM_DESC(dvb_powerdown_on_sleep, "0: do not power down, 1: turn LNB voltage off on sleep (default)");
+module_param(dvb_mfe_wait_time, int, 0644);
+MODULE_PARM_DESC(dvb_mfe_wait_time, "Wait up to <mfe_wait_time> seconds on open() for multi-frontend to become available (default:5 seconds)");
 
 #define dprintk if (dvb_frontend_debug) printk
 
@@ -1706,13 +1709,46 @@ static int dvb_frontend_open(struct inode *inode, struct file *file)
         struct dvb_device *dvbdev = file->private_data;
         struct dvb_frontend *fe = dvbdev->priv;
         struct dvb_frontend_private *fepriv = fe->frontend_priv;
+        struct dvb_adapter *adapter = fe->dvb;
+        struct dvb_device *mfedev;
+        struct dvb_frontend *mfe;
+        struct dvb_frontend_private *mfepriv;
+        int mferetry;
         int ret;
 
         dprintk ("%s\n", __func__);
 
+        if (adapter->mfe_shared) {
+                mutex_lock (&adapter->mfe_lock);
+                if (adapter->mfe_dvbdev != dvbdev) {
+                        if (adapter->mfe_dvbdev) {
+                                mfedev = adapter->mfe_dvbdev;
+                                mfe = mfedev->priv;
+                                mfepriv = mfe->frontend_priv;
+                                mutex_unlock (&adapter->mfe_lock);
+                                mferetry = (dvb_mfe_wait_time << 1);
+                                while (mferetry-- && (mfedev->users != -1 || mfepriv->thread != NULL)) {
+                                        if(msleep_interruptible(500)) {
+                                                if(signal_pending(current))
+                                                        return -EINTR;
+                                        }
+                                }
+                                mutex_lock (&adapter->mfe_lock);
+                                mfedev = adapter->mfe_dvbdev;
+                                mfe = mfedev->priv;
+                                mfepriv = mfe->frontend_priv;
+                                if (mfedev->users != -1 || mfepriv->thread != NULL) {
+                                        ret = -EBUSY;
+                                        goto err0;
+                                }
+                        }
+                        adapter->mfe_dvbdev = dvbdev;
+                }
+        }
+
         if (dvbdev->users == -1 && fe->ops.ts_bus_ctrl) {
                 if ((ret = fe->ops.ts_bus_ctrl(fe, 1)) < 0)
-                        return ret;
+                        goto err0;
         }
 
         if ((ret = dvb_generic_open (inode, file)) < 0)
@@ -1732,6 +1768,8 @@ static int dvb_frontend_open(struct inode *inode, struct file *file)
                 fepriv->events.eventr = fepriv->events.eventw = 0;
         }
 
+        if (adapter->mfe_shared)
+                mutex_unlock (&adapter->mfe_lock);
         return ret;
 
 err2:
@@ -1739,6 +1777,9 @@ err2:
 err1:
         if (dvbdev->users == -1 && fe->ops.ts_bus_ctrl)
                 fe->ops.ts_bus_ctrl(fe, 0);
+err0:
+        if (adapter->mfe_shared)
+                mutex_unlock (&adapter->mfe_lock);
         return ret;
 }
 
diff --git a/drivers/media/dvb/dvb-core/dvbdev.c b/drivers/media/dvb/dvb-core/dvbdev.c
index 665776d72a48..a113744a56cc 100644
--- a/drivers/media/dvb/dvb-core/dvbdev.c
+++ b/drivers/media/dvb/dvb-core/dvbdev.c
@@ -326,6 +326,9 @@ int dvb_register_adapter(struct dvb_adapter *adap, const char *name,
         adap->name = name;
         adap->module = module;
         adap->device = device;
+        adap->mfe_shared = 0;
+        adap->mfe_dvbdev = NULL;
+        mutex_init (&adap->mfe_lock);
 
         list_add_tail (&adap->list_head, &dvb_adapter_list);
 
diff --git a/drivers/media/dvb/dvb-core/dvbdev.h b/drivers/media/dvb/dvb-core/dvbdev.h
index 89d12dc477a7..574e336bac35 100644
--- a/drivers/media/dvb/dvb-core/dvbdev.h
+++ b/drivers/media/dvb/dvb-core/dvbdev.h
@@ -62,6 +62,10 @@ struct dvb_adapter {
         struct device *device;
 
         struct module *module;
+
+        int mfe_shared;                 /* indicates mutually exclusive frontends */
+        struct dvb_device *mfe_dvbdev;  /* frontend device in use */
+        struct mutex mfe_lock;          /* access lock for thread creation */
 };