Commit | Line | Data |
---|---|---|
771fe6b9 | 1 | config DRM_RADEON_KMS |
1ca137cd | 2 | bool "Enable modesetting on radeon by default - NEW DRIVER" |
771fe6b9 | 3 | depends on DRM_RADEON |
771fe6b9 | 4 | help |
1ca137cd DA |
5 | Choose this option if you want kernel modesetting enabled by default. |
6 | ||
7 | This is a completely new driver. It's only part of the existing drm | |
8 | for compatibility reasons. It requires an entirely different graphics | |
9 | stack above it and works very differently from the old drm stack. | |
10 | i.e. don't enable this unless you know what you are doing it may | |
11 | cause issues or bugs compared to the previous userspace driver stack. | |
771fe6b9 JG |
12 | |
13 | When kernel modesetting is enabled the IOCTL of radeon/drm | |
14 | driver are considered as invalid and an error message is printed | |
15 | in the log and they return failure. | |
16 | ||
17 | KMS enabled userspace will use new API to talk with the radeon/drm | |
18 | driver. The new API provide functions to create/destroy/share/mmap | |
19 | buffer object which are then managed by the kernel memory manager | |
20 | (here TTM). In order to submit command to the GPU the userspace | |
21 | provide a buffer holding the command stream, along this buffer | |
22 | userspace have to provide a list of buffer object used by the | |
23 | command stream. The kernel radeon driver will then place buffer | |
24 | in GPU accessible memory and will update command stream to reflect | |
25 | the position of the different buffers. | |
26 | ||
27 | The kernel will also perform security check on command stream | |
28 | provided by the user, we want to catch and forbid any illegal use | |
29 | of the GPU such as DMA into random system memory or into memory | |
30 | not owned by the process supplying the command stream. This part | |
31 | of the code is still incomplete and this why we propose that patch | |
32 | as a staging driver addition, future security might forbid current | |
33 | experimental userspace to run. | |
34 | ||
35 | This code support the following hardware : R1XX,R2XX,R3XX,R4XX,R5XX | |
36 | (radeon up to X1950). Works is underway to provide support for R6XX, | |
37 | R7XX and newer hardware (radeon from HD2XXX to HD4XXX). |