[PATCH] USB: drivers/usb/media/w9968cf.c: remove hooks for the vpp module

- the w9968cf-vpp module is not intended for inclusion into the kernel
- the upstream w9968cf package shipping the w9968cf-vpp module suggests
  to simply replace the w9968cf module shipped with the kernel

Therefore, there seems to be no good reason spending some bytes of
kernel memory for hooks for the w9968cf-vpp module.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Luca Risolia <luca.risolia@studio.unibo.it>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Documentation/usb/w9968cf.txt

@@ -57,16 +57,12 @@ based cameras should be supported as well.
 The driver is divided into two modules: the basic one, "w9968cf", is needed for
 the supported devices to work; the second one, "w9968cf-vpp", is an optional
 module, which provides some useful video post-processing functions like video
-decoding, up-scaling and colour conversions. Once the driver is installed,
-every time an application tries to open a recognized device, "w9968cf" checks
-the presence of the "w9968cf-vpp" module and loads it automatically by default.
+decoding, up-scaling and colour conversions.
 
-Please keep in mind that official kernels do not include the second module for
-performance purposes. However it is always recommended to download and install
-the latest and complete release of the driver, replacing the existing one, if
-present: it will be still even possible not to load the "w9968cf-vpp" module at
-all, if you ever want to. Another important missing feature of the version in
-the official Linux 2.4 kernels is the writeable /proc filesystem interface.
+Note that the official kernels do neither include nor support the second
+module for performance purposes. Therefore, it is always recommended to
+download and install the latest and complete release of the driver,
+replacing the existing one, if present.
 
 The latest and full-featured version of the W996[87]CF driver can be found at:
 http://www.linux-projects.org. Please refer to the documentation included in
@@ -201,22 +197,6 @@ Note:            The kernel must be compiled with the CONFIG_KMOD option
                  enabled for the 'ovcamchip' module to be loaded and for
                  this parameter to be present.
 -------------------------------------------------------------------------------
-Name:           vppmod_load
-Type:           bool
-Syntax:         <0|1>
-Description:    Automatic 'w9968cf-vpp' module loading: 0 disabled, 1 enabled.
-                If enabled, every time an application attempts to open a
-                camera, 'insmod' searches for the video post-processing module
-                in the system and loads it automatically (if present).
-                The optional 'w9968cf-vpp' module adds extra image manipulation
-                capabilities to the 'w9968cf' module,like software up-scaling,
-                colour conversions and video decompression for very high frame
-                rates.
-Default:        1
-Note:           The kernel must be compiled with the CONFIG_KMOD option
-                enabled for the 'w9968cf-vpp' module to be loaded and for
-                this parameter to be present.
--------------------------------------------------------------------------------
 Name:           simcams 
 Type:           int 
 Syntax:         <n> 

drivers/usb/media/w9968cf.c

@@ -62,7 +62,6 @@ MODULE_LICENSE(W9968CF_MODULE_LICENSE);
 MODULE_SUPPORTED_DEVICE("Video");
 
 static int ovmod_load = W9968CF_OVMOD_LOAD;
-static int vppmod_load = W9968CF_VPPMOD_LOAD;
 static unsigned short simcams = W9968CF_SIMCAMS;
 static short video_nr[]={[0 ... W9968CF_MAX_DEVICES-1] = -1}; /*-1=first free*/
 static unsigned int packet_size[] = {[0 ... W9968CF_MAX_DEVICES-1] = 
@@ -107,7 +106,6 @@ static unsigned int param_nv[24]; /* number of values per parameter */
 
 #ifdef CONFIG_KMOD
 module_param(ovmod_load, bool, 0644);
-module_param(vppmod_load, bool, 0444);
 #endif
 module_param(simcams, ushort, 0644);
 module_param_array(video_nr, short, &param_nv[0], 0444);
@@ -150,18 +148,6 @@ MODULE_PARM_DESC(ovmod_load,
                  "\ninto memory."
                  "\nDefault value is "__MODULE_STRING(W9968CF_OVMOD_LOAD)"."
                  "\n");
-MODULE_PARM_DESC(vppmod_load, 
-                 "\n<0|1> Automatic 'w9968cf-vpp' module loading."
-                 "\n0 disabled, 1 enabled."
-                 "\nIf enabled, every time an application attempts to open a"
-                 "\ncamera, 'insmod' searches for the video post-processing"
-                 "\nmodule in the system and loads it automatically (if"
-                 "\npresent). The optional 'w9968cf-vpp' module adds extra"
-                 "\n image manipulation functions to the 'w9968cf' module,like"
-                 "\nsoftware up-scaling,colour conversions and video decoding"
-                 "\nfor very high frame rates."
-                 "\nDefault value is "__MODULE_STRING(W9968CF_VPPMOD_LOAD)"."
-                 "\n");
 #endif
 MODULE_PARM_DESC(simcams, 
                  "\n<n> Number of cameras allowed to stream simultaneously."
@@ -492,10 +478,6 @@ static void w9968cf_push_frame(struct w9968cf_device*, u8 f_num);
 static void w9968cf_pop_frame(struct w9968cf_device*,struct w9968cf_frame_t**);
 static void w9968cf_release_resources(struct w9968cf_device*);
 
-/* Intermodule communication */
-static int w9968cf_vppmod_detect(struct w9968cf_device*);
-static void w9968cf_vppmod_release(struct w9968cf_device*);
-
 
 
 /****************************************************************************
@@ -2737,9 +2719,7 @@ static int w9968cf_open(struct inode* inode, struct file* filp)
 	cam->streaming = 0;
 	cam->misconfigured = 0;
 
-	if (!w9968cf_vpp)
-		if ((err = w9968cf_vppmod_detect(cam)))
-			goto out;
+	w9968cf_adjust_configuration(cam);
 
 	if ((err = w9968cf_allocate_memory(cam)))
 		goto deallocate_memory;
@@ -2766,7 +2746,6 @@ static int w9968cf_open(struct inode* inode, struct file* filp)
 
 deallocate_memory:
 	w9968cf_deallocate_memory(cam);
-out:
 	DBG(2, "Failed to open the video device")
 	up(&cam->dev_sem);
 	up_read(&w9968cf_disconnect);
@@ -2784,8 +2763,6 @@ static int w9968cf_release(struct inode* inode, struct file* filp)
 
 	w9968cf_stop_transfer(cam);
 
-	w9968cf_vppmod_release(cam);
-
 	if (cam->disconnected) {
 		w9968cf_release_resources(cam);
 		up(&cam->dev_sem);
@@ -3681,106 +3658,6 @@ static struct usb_driver w9968cf_usb_driver = {
  * Module init, exit and intermodule communication                          *
  ****************************************************************************/
 
-static int w9968cf_vppmod_detect(struct w9968cf_device* cam)
-{
-	if (!w9968cf_vpp)
-		if (vppmod_load)
-			request_module("w9968cf-vpp");
-
-	down(&w9968cf_vppmod_lock);
-
-	if (!w9968cf_vpp) {
-		DBG(4, "Video post-processing module not detected")
-		w9968cf_adjust_configuration(cam);
-		goto out;
-	}
-
-	if (!try_module_get(w9968cf_vpp->owner)) {
-		DBG(1, "Couldn't increment the reference count of "
-		       "the video post-processing module")
-		up(&w9968cf_vppmod_lock);
-		return -ENOSYS;
-	}
-
-	w9968cf_vpp->busy++;
-
-	DBG(5, "Video post-processing module detected")
-
-out:
-	up(&w9968cf_vppmod_lock);
-	return 0;
-}
-
-
-static void w9968cf_vppmod_release(struct w9968cf_device* cam)
-{
-	down(&w9968cf_vppmod_lock);
-
-	if (w9968cf_vpp && w9968cf_vpp->busy) {
-		module_put(w9968cf_vpp->owner);
-		w9968cf_vpp->busy--;
-		wake_up(&w9968cf_vppmod_wait);
-		DBG(5, "Video post-processing module released")
-	}
-
-	up(&w9968cf_vppmod_lock);
-}
-
-
-int w9968cf_vppmod_register(struct w9968cf_vpp_t* vpp)
-{
-	down(&w9968cf_vppmod_lock);
-
-	if (w9968cf_vpp) {
-		KDBG(1, "Video post-processing module already registered")
-		up(&w9968cf_vppmod_lock);
-		return -EINVAL;
-	}
-
-	w9968cf_vpp = vpp;
-	w9968cf_vpp->busy = 0;
-
-	KDBG(2, "Video post-processing module registered")
-	up(&w9968cf_vppmod_lock);
-	return 0;
-}
-
-
-int w9968cf_vppmod_deregister(struct w9968cf_vpp_t* vpp)
-{
-	down(&w9968cf_vppmod_lock);
-
-	if (!w9968cf_vpp) {
-		up(&w9968cf_vppmod_lock);
-		return -EINVAL;
-	}
-
-	if (w9968cf_vpp != vpp) {
-		KDBG(1, "Only the owner can unregister the video "
-		        "post-processing module")
-		up(&w9968cf_vppmod_lock);
-		return -EINVAL;
-	}
-
-	if (w9968cf_vpp->busy) {
-		KDBG(2, "Video post-processing module busy. Wait for it to be "
-		        "released...")
-		up(&w9968cf_vppmod_lock);
-		wait_event(w9968cf_vppmod_wait, !w9968cf_vpp->busy);
-		w9968cf_vpp = NULL;
-		goto out;
-	}
-
-	w9968cf_vpp = NULL;
-
-	up(&w9968cf_vppmod_lock);
-
-out:
-	KDBG(2, "Video post-processing module unregistered")
-	return 0;
-}
-
-
 static int __init w9968cf_module_init(void)
 {
 	int err;
@@ -3810,6 +3687,3 @@ static void __exit w9968cf_module_exit(void)
 module_init(w9968cf_module_init);
 module_exit(w9968cf_module_exit);
 
-
-EXPORT_SYMBOL(w9968cf_vppmod_register);
-EXPORT_SYMBOL(w9968cf_vppmod_deregister);

drivers/usb/media/w9968cf.h

@@ -195,7 +195,6 @@ enum w9968cf_vpp_flag {
 };
 
 static struct w9968cf_vpp_t* w9968cf_vpp;
-static DECLARE_MUTEX(w9968cf_vppmod_lock);
 static DECLARE_WAIT_QUEUE_HEAD(w9968cf_vppmod_wait);
 
 static LIST_HEAD(w9968cf_dev_list); /* head of V4L registered cameras list */

drivers/usb/media/w9968cf_vpp.h

@@ -37,7 +37,4 @@ struct w9968cf_vpp_t {
 	u8 busy; /* read-only flag: module is/is not in use */
 };
 
-extern int w9968cf_vppmod_register(struct w9968cf_vpp_t*);
-extern int w9968cf_vppmod_deregister(struct w9968cf_vpp_t*);
-
 #endif /* _W9968CF_VPP_H_ */