1config DRM_RADEON_KMS
2	bool "Enable modesetting on radeon by default - NEW DRIVER"
3	depends on DRM_RADEON
4	select BACKLIGHT_CLASS_DEVICE
5	help
6	  Choose this option if you want kernel modesetting enabled by default.
7
8	  This is a completely new driver. It's only part of the existing drm
9	  for compatibility reasons. It requires an entirely different graphics
10	  stack above it and works very differently from the old drm stack.
11	  i.e. don't enable this unless you know what you are doing it may
12	  cause issues or bugs compared to the previous userspace driver stack.
13
14	  When kernel modesetting is enabled the IOCTL of radeon/drm
15	  driver are considered as invalid and an error message is printed
16	  in the log and they return failure.
17
18	  KMS enabled userspace will use new API to talk with the radeon/drm
19	  driver. The new API provide functions to create/destroy/share/mmap
20	  buffer object which are then managed by the kernel memory manager
21	  (here TTM). In order to submit command to the GPU the userspace
22	  provide a buffer holding the command stream, along this buffer
23	  userspace have to provide a list of buffer object used by the
24	  command stream. The kernel radeon driver will then place buffer
25	  in GPU accessible memory and will update command stream to reflect
26	  the position of the different buffers.
27
28	  The kernel will also perform security check on command stream
29	  provided by the user, we want to catch and forbid any illegal use
30	  of the GPU such as DMA into random system memory or into memory
31	  not owned by the process supplying the command stream.
32