drm/msm: fix inconsequential typo

Small typo I noticed in the mdp4_plane code.. no consequence because
PIPE_SRC_XY and PIPE_DST_XY have same register layout.

Signed-off-by: Rob Clark <robdclark@gmail.com>
squash! drm/msm: add mdp5/apq8x74
WIP: drm/msm: mdp4 pageflip fixes

Backport a few fixes found in the course of getting mdp5 working.
There is a window of time after pageflip is requested, before we
start scanning out the new fb (ie. while we are waiting for gpu).
During that time we need to continue holding a reference to the
still-current scanout fb, to avoid the backing gem bo's from being
destroyed.

Possibly a common mdp_crtc parent class could be useful to share
some of this logic between mdp4_crtc and mdp5_crtc.  OTOH, this
all can be removed from the driver once atomic is in place, as
plane/crtc updates get deferred until all fb's are ready before
calling in to .page_flip(), etc.
WIP: drm/msm: mdp4 cursor fixes

It seems we need to update all cursor registers from vblank.  This
appears to be the cause of intermittent underflows when enabling/
disabling cursor.
WIP: drm/msm: add rd logging debugfs

To ease debugging, add debugfs file which can be cat/tail'd to log
submits, along with fence #.  If GPU hangs, you can look at 'gpu'
debugfs file to find last completed fence and current register state,
and compare with logged rd file to narrow down the DRAW_INDX which
triggered the GPU hang.

Conflicts:
	drivers/gpu/drm/msm/msm_gpu.c

Conflicts:
	drivers/gpu/drm/msm/Makefile
	drivers/gpu/drm/msm/msm_drv.h
WIP: drm/msm: add module param to enable register dumps on hang, for debugging..
WIP: drm/msm: add perf logging debugfs

Conflicts:
	drivers/gpu/drm/msm/Makefile
	drivers/gpu/drm/msm/adreno/a3xx_gpu.c
WIP: drm/msm: add trace points

Conflicts:
	drivers/gpu/drm/msm/msm_drv.c
	drivers/gpu/drm/msm/msm_gpu.c
WIP: perf/timechart: support for GPU

Show GPU as another "CPU" on the timeline, so we can see where it is
busy and idle.  Also show pending flips (green bar on the GPU), as well
as places where processes are blocked on a fence (yellow bar on the
process).

Currently a bit hacky.  And looking for drm/msm specific traces.  We
should probably make a set of generic traces that can be used by all drm
drivers, and use these trace events in perf.  (For other GPU's we
probably want a way to be able to visualize activity on multiple rings.)