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author | Philipp Zabel <p.zabel@pengutronix.de> | 2017-05-19 16:05:51 +0200 |
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committer | Philipp Zabel <p.zabel@pengutronix.de> | 2017-07-17 12:58:11 +0200 |
commit | 790cb4c7c9545953d22d3d425e49b36a711bae5b (patch) | |
tree | 33913a427dd96b884fa6786cebb74426fd6a5b8a /crypto/ecb.c | |
parent | 58dff39904c02199b80395dac2fa3dec0d8f3861 (diff) | |
download | blackbird-op-linux-790cb4c7c9545953d22d3d425e49b36a711bae5b.tar.gz blackbird-op-linux-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 <l.stach@pengutronix.de>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Diffstat (limited to 'crypto/ecb.c')
0 files changed, 0 insertions, 0 deletions