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7a2ec4a0a5
To get sensible vblank timestamping behaviour we need to feed
the vmax based timings to the vblank code, otherwise it'll chop
off the scanline counter when it exceeds the minumum vtotal.
Additionally with VRR we have three cases to consider when we
generate the vblank timestamp:
1) we are in vertical active
-> nothing special needs to be done, just return the current
scanout position and the core will calculate the timestamp
corresponding to the past time when the current vertical
active started
2) we are in vertical blank and no push has been sent
-> the hardware will keep extending the vblank presumably
to its maximum length, so we make the timestmap match the
expected time when the max length vblank will end. Since
the timings used for this are now based on vmax nothing
special actually needs to be done
3) we are in vblank and a push has been sent so the vblank is
about to terminate
-> presumably we want the timestmap to accurately reflect
when the vblank will terminate, so we use the sampled
frame timestamp vs. current timestamp to guesstimate
how far along the vblank exit we are, and then we
adjust the reported scanout position accordingly so
that the core will see that the vblank is close to
ending.
v2:
* Fix the else if (use_scanline_Counter) (Manasi)
Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Manasi Navare <manasi.d.navare@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210122232647.22688-17-manasi.d.navare@intel.com
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