f9cb8d8d83 fixed various race conditions with CTL flush, in particular
flushing and sending the START signal before encoder state was updated.
But it did this a little too well in some cases that don't trigger
encoder->enable(), and CTL[n].FLUSH would never be set. When page flips
happen it would paper over the bug, since the first plag flip would
flush out the state to the hardware.
The issue could be reproduced with, for example, modetest (without the
'-v' argument).
Fixes: f9cb8d8d83 drm/msm/mdp5: rework CTL START signal handling
Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
For DSI cmd-mode and writeback, we need to write the CTL's START
register to kick things off, but we only want to do that once both
the encoder and the crtc have a chance to write their corresponding
flush bits. The difficulty is that when there is a full modeset
(ie. encoder state has changed) we want to defer the start until
encoder->enable(). But if only plane's have changed, we want to do
this from crtc->commit().
The start_mask was a previous attempt to handle this, but it didn't
really do the right thing since atomic conversion.
Instead track in the crtc state that the start should be deferred,
set to try from encoder's (or in future writeback's) atomic_check().
This way the state is part of the atomic state, and rollback can
work properly if an atomic test fails.
Signed-off-by: Rob Clark <robdclark@gmail.com>
Since new display controller is called "dpu" instead of "mdp". Lets
make the name of the toplevel directory for the display controllers a
bit more generic.
Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
