media: usbvision: deprecate driver

The driver is deprecated and scheduled for removal by the end
of 2020. The reason is that this driver is for old and obsolete
hardware, and it produces a continuous stream of syzbot errors due
to poor code.

In order to prevent removal the following actions would have to
be taken:

- clean up the code
- convert to the vb2 framework
- fix the disconnect and free-on-last-user handling (i.e., add
a release callback for struct v4l2_device and rework the code
to use that correctly).

Signed-off-by: Hans Verkuil <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

MAINTAINERS

···
 T:	git git://linuxtv.org/media_tree.git
 W:	https://linuxtv.org
 S:	Odd Fixes
-F:	drivers/media/usb/usbvision/
+F:	drivers/staging/media/usbvision/
 
 USB WEBCAM GADGET
 M:	Laurent Pinchart <[e-mail]>

drivers/media/usb/Kconfig

···
 	comment "Analog TV USB devices"
 source "drivers/media/usb/pvrusb2/Kconfig"
 source "drivers/media/usb/hdpvr/Kconfig"
-source "drivers/media/usb/usbvision/Kconfig"
 source "drivers/media/usb/stk1160/Kconfig"
 source "drivers/media/usb/go7007/Kconfig"
 endif

drivers/media/usb/Makefile

···
 obj-$(CONFIG_VIDEO_AU0828) += au0828/
 obj-$(CONFIG_VIDEO_HDPVR)	+= hdpvr/
 obj-$(CONFIG_VIDEO_PVRUSB2) += pvrusb2/
-obj-$(CONFIG_VIDEO_USBVISION) += usbvision/
 obj-$(CONFIG_VIDEO_STK1160) += stk1160/
 obj-$(CONFIG_VIDEO_CX231XX) += cx231xx/
 obj-$(CONFIG_VIDEO_TM6000) += tm6000/

drivers/media/usb/usbvision/Kconfig drivers/staging/media/usbvision/Kconfig

···
 # SPDX-License-Identifier: GPL-2.0-only
 config VIDEO_USBVISION
-	tristate "USB video devices based on Nogatech NT1003/1004/1005"
+	tristate "USB video devices based on Nogatech NT1003/1004/1005 (Deprecated)"
 	depends on I2C && VIDEO_V4L2
 	select VIDEO_TUNER
 	select VIDEO_SAA711X if MEDIA_SUBDRV_AUTOSELECT
···
 	  There are more than 50 different USB video devices based on
 	  NT1003/1004/1005 USB Bridges. This driver enables using those
 	  devices.
+
+	  This driver is deprecated and scheduled for removal by the
+	  end of 2020. See the TODO file in drivers/staging/media/usbvision
+	  for a list of actions that have to be done in order to prevent
+	  removal of this driver.
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called usbvision.

drivers/staging/media/Kconfig

···
 
 source "drivers/staging/media/rkisp1/Kconfig"
 
+if MEDIA_ANALOG_TV_SUPPORT
+source "drivers/staging/media/usbvision/Kconfig"
+endif
+
 endif

drivers/staging/media/Makefile

···
 obj-$(CONFIG_SOC_CAMERA)	+= soc_camera/
 obj-$(CONFIG_PHY_ROCKCHIP_DPHY_RX0)	+= phy-rockchip-dphy-rx0/
 obj-$(CONFIG_VIDEO_ROCKCHIP_ISP1)	+= rkisp1/
+obj-$(CONFIG_VIDEO_USBVISION)	+= usbvision/

drivers/staging/media/usbvision/TODO

···
+The driver is deprecated and scheduled for removal by the end
+of 2020.
+
+In order to prevent removal the following actions would have to
+be taken:
+
+- clean up the code
+- convert to the vb2 framework
+- fix the disconnect and free-on-last-user handling (i.e., add
+  a release callback for struct v4l2_device and rework the code
+  to use that correctly).