Previously, on every modeset we would allocate new display list
memory, recompute changed planes, write all of them to the new memory,
and pointed scanout at the new list (which will latch approximately at
the next line of scanout). We let
drm_atomic_helper_wait_for_vblanks() decide whether we needed to wait
for a vblank after a modeset before cleaning up the old state and
letting the next modeset proceed, and on legacy cursor updates we
wouldn't wait. If you moved the cursor fast enough, we could
potentially wrap around the display list memory area and overwrite the
existing display list while it was still being scanned out, resulting
in the HVS scanning out garbage or just halting.
Instead of making cursor updates wait for scanout to move to the new
display list area (which introduces significant cursor lag in X), we
just rewrite our current display list.
Signed-off-by: Eric Anholt <eric@anholt.net>
An async pageflip stores the modeset to be done and executes it once
the BOs are ready to be displayed. This gets us about 3x performance
in full screen rendering with pageflipping.
Signed-off-by: Eric Anholt <eric@anholt.net>
Keep the fbdev_cma pointer around so we can use it on hotplog and close
to ensure the frame buffer console is in a useful state.
Signed-off-by: Derek Foreman <derekf@osg.samsung.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
This is enough for fbcon and bringing up X using
xf86-video-modesetting. It doesn't support the 3D accelerator or
power management yet.
v2: Drop FB_HELPER select thanks to Archit's patches. Do manual init
ordering instead of using the .load hook. Structure registration
more like tegra's, but still using the typical "component" code.
Drop no-op hooks for atomic_begin and mode_fixup() now that
they're optional. Drop sentinel in Makefile. Fix minor style
nits I noticed on another reread.
v3: Use the new bcm2835 clk driver to manage pixel/HSM clocks instead
of having a fixed video mode. Use exynos-style component driver
matching instead of devicetree nodes to list the component driver
instances. Rename compatibility strings to say bcm2835, and
distinguish pv0/1/2. Clean up some h/vsync code, and add in
interlaced mode setup. Fix up probe/bind error paths. Use
bitops.h macros for vc4_regs.h
v4: Include i2c.h, allow building under COMPILE_TEST, drop msleep now
that other bugs have been fixed, add timeouts to cpu_relax()
loops, rename hpd-gpio to hpd-gpios.
Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
