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