diff options
| author | Philipp Zabel <[email protected]> | 2017-05-19 14:05:51 +0000 |
|---|---|---|
| committer | Philipp Zabel <[email protected]> | 2017-07-17 10:58:11 +0000 |
| commit | 790cb4c7c9545953d22d3d425e49b36a711bae5b (patch) | |
| tree | 33913a427dd96b884fa6786cebb74426fd6a5b8a /drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c | |
| parent | drm/imx: ipuv3-plane: use fb local variable instead of state->fb (diff) | |
| download | kernel-790cb4c7c9545953d22d3d425e49b36a711bae5b.tar.gz kernel-790cb4c7c9545953d22d3d425e49b36a711bae5b.zip | |
drm/imx: lock scanout transfers for consecutive bursts
Because of its shallow queues and limited reordering ability, the i.MX6Q
memory controller likes AXI bursts of consecutive addresses a lot.
To optimize memory access performance, lock the IPU scanout channels for
a number of burst accesses each, before switching to the next channel.
The burst size and length of a locked burst chain are chosen not to
overshoot the stride.
Enabling the 8-burst channel lock on a single 1920x1080@60Hz RGBx
scanout (474 MiB/s of 64-byte IPU memory read accesses) reduces the
reported memory controller busy cycles from 46% to below 28% on an
otherwise idle i.MX6Q.
Tested-by: Lucas Stach <[email protected]>
Signed-off-by: Philipp Zabel <[email protected]>
Diffstat (limited to 'drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c')
0 files changed, 0 insertions, 0 deletions