[linux-dvb] [patch] cx22702: frontend register fixes

[Gerd Knorr <kraxel@bytesex.org>]

  Hi,

This updates the cx22702 frontend driver:

 * make it ignore any non-dvb card i2c adapters.
 * fixup the registering / unregistering order and make it more robust.

This one together with the latest v4l snapshot makes cx88 + cx22702 work
nicely together with any module load order.  Unloading the modules works
as well of course ;)

  Gerd

--- drivers/media/dvb/frontends/cx22702.c.kraxel	2004-09-15 16:44:13.000000000 +0200
+++ drivers/media/dvb/frontends/cx22702.c	2004-09-15 17:17:27.422581128 +0200
@@ -734,6 +734,12 @@
 	int minfreq;
 	int pll_type;
 
+	if (0 == (adapter->class & I2C_CLASS_TV_DIGITAL)) {
+		dprintk("Ignoring adapter 0x%x:%s (no digital tv card).\n",
+			adapter->id, adapter->name);
+		return 0;
+	}
+
 	dprintk("Trying to attach to adapter 0x%x:%s.\n",
 		adapter->id, adapter->name);
 
@@ -780,17 +786,6 @@
 		kfree(state);
 		return ret;
 	}
-
-	BUG_ON(!state->dvb);
-
-	if ((ret = dvb_register_frontend(cx22702_ioctl, state->dvb, state,
-		&state->cx22702_info, THIS_MODULE))) {
-		i2c_detach_client(client);
-		kfree(client);
-		kfree(state);
-		return ret;
-	}
-
 	return 0;	
 }
 
@@ -798,9 +793,11 @@
 {
 	struct cx22702_state *state = i2c_get_clientdata(client);
 
-	dvb_unregister_frontend (cx22702_ioctl, state->dvb);
+	if (NULL != state->dvb) {
+		dvb_unregister_frontend (cx22702_ioctl, state->dvb);
+		state->dvb = NULL;
+	}
 	i2c_detach_client(client);
-	BUG_ON(state->dvb);
 	kfree(client);
 	return 0;
 }
@@ -808,12 +805,25 @@
 static int command(struct i2c_client *client, unsigned int cmd, void *arg)
 {
 	struct cx22702_state *state = i2c_get_clientdata(client);
+	int rc;
 
 	switch(cmd) {
 	case FE_REGISTER:
+		if (NULL != state->dvb)
+			break;
 		state->dvb = arg;
+		rc = dvb_register_frontend(cx22702_ioctl, state->dvb, state,
+					   &state->cx22702_info, THIS_MODULE);
+		if (0 != rc) {
+			printk("cx22702: dvb_register_frontend failed with rc=%d\n",rc);
+			state->dvb = NULL;
+			return rc;
+		}
 		break;
 	case FE_UNREGISTER:
+		if (NULL == state->dvb)
+			break;
+		dvb_unregister_frontend (cx22702_ioctl, state->dvb);
 		state->dvb = NULL;
 		break;
 	default: