V4L/DVB (10190): cx88: Fix some Kbuild troubles

As Randy Dunlap <randy.dunlap@oracle.com> reported, cx88 has some compilation issues:

drivers/built-in.o: In function `cx88_call_i2c_clients':
(.text+0x20af17): undefined reference to `videobuf_dvb_get_frontend'
drivers/built-in.o: In function `cx8802_probe':
cx88-mpeg.c:(.devinit.text+0x268c4): undefined reference to `videobuf_dvb_alloc_frontend'
cx88-mpeg.c:(.devinit.text+0x268ea): undefined reference to `videobuf_dvb_dealloc_frontends'

With those configs:

CONFIG_VIDEO_CX88=y
CONFIG_VIDEO_CX88_BLACKBIRD=y
CONFIG_VIDEO_CX88_DVB=m
CONFIG_DVB_CORE=m

After carefully examining the code, with the current code, several cx88 drivers
(cx8800, cx8802, cx88_dvb and cx88_blackbird) should be compiled as a module,
if one of them is marked as such. Just fixing Kconfig could create a very complex
set of rules. Also, this hides a problem with the current approach where the dvb
functionality weren't confined inside dvb module.

What happens is that:
	- cx88-i2c (part of cx8800) has some special rules if DVB;
	- cx88-mpeg (cx8802 module) has also part of DVB init code;
	- cx88-dvb has the rest of the dvb code;
	- cx88-blackbird can be used with cx88-mpeg, having cx88-dvb or not.

So, instead of doing some tricks at Kconfig and wait for a next breakage,
this patch moves the dvb code inside cx88-i2c and cx88-mpeg into cx88-dvb.

Another problem is that cx8802 were being compiled, even without cx88-dvb
and cx88-blackbird modules.

While on this code, let's fix also a reported problem:
http://www.linuxtv.org/pipermail/linux-dvb/2009-January/031225.html

A solution for the issue were proposed here:
http://www.mail-archive.com/linux-media@vger.kernel.org/msg00021.html

Thanks to Randy, Andy, Gregoire and Thomas for helping us to detect
and solve the issues.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 4 insertions, 26 deletions

diff --git a/drivers/media/video/cx88/cx88-mpeg.c b/drivers/media/video/cx88/cx88-mpeg.c
index 59164fc..b295b76 100644
--- a/drivers/media/video/cx88/cx88-mpeg.c
+++ b/drivers/media/video/cx88/cx88-mpeg.c
@@ -787,6 +787,9 @@ static int __devinit cx8802_probe(struct pci_dev *pci_dev,
 	dev->pci = pci_dev;
 	dev->core = core;
 
+	/* Maintain a reference so cx88-video can query the 8802 device. */
+	core->dvbdev = dev;
+
 	err = cx8802_init_common(dev);
 	if (err != 0)
 		goto fail_free;
@@ -794,32 +797,6 @@ static int __devinit cx8802_probe(struct pci_dev *pci_dev,
 	INIT_LIST_HEAD(&dev->drvlist);
 	list_add_tail(&dev->devlist,&cx8802_devlist);
 
-#if defined(CONFIG_VIDEO_CX88_DVB) || defined(CONFIG_VIDEO_CX88_DVB_MODULE)
-	mutex_init(&dev->frontends.lock);
-	INIT_LIST_HEAD(&dev->frontends.felist);
-
-	if (core->board.num_frontends) {
-		struct videobuf_dvb_frontend *fe;
-		int i;
-
-		printk(KERN_INFO "%s() allocating %d frontend(s)\n", __func__,
-			core->board.num_frontends);
-		for (i = 1; i <= core->board.num_frontends; i++) {
-			fe = videobuf_dvb_alloc_frontend(&dev->frontends, i);
-			if(fe == NULL) {
-				printk(KERN_ERR "%s() failed to alloc\n",
-					__func__);
-				videobuf_dvb_dealloc_frontends(&dev->frontends);
-				err = -ENOMEM;
-				goto fail_free;
-			}
-		}
-	}
-#endif
-
-	/* Maintain a reference so cx88-video can query the 8802 device. */
-	core->dvbdev = dev;
-
 	/* now autoload cx88-dvb or cx88-blackbird */
 	request_modules(dev);
 	return 0;
@@ -827,6 +804,7 @@ static int __devinit cx8802_probe(struct pci_dev *pci_dev,
  fail_free:
 	kfree(dev);
  fail_core:
+	core->dvbdev = NULL;
 	cx88_core_put(core,pci_dev);
 	return err;
 }