[PATCH] drm/i915/psr: Send update also on invalidate

[Jouni Högander]

Currently we are observing mouse cursor stuttering when using
xrandr --scaling=1.2x1.2. X scaling/transformation seems to be
doing fronbuffer rendering. It seems to be assuming updates are
sent to panel while drawing is done.

Earlier we were disabling PSR in frontbuffer invalidate call back
i.e. when drawing in X started. PSR was re-enabled in frontbuffer
flush callback (dirtyfb ioctl). This was working fine with X
scaling/transformation. Now we are just enabling continuous full
frame (cff) in PSR invalidate callback. Enabling cff doesn't
trigger any updates. I.e. there are no updates on screen before
PSR flush callback is made. X seems to be doing several updates
in frontbuffer before doing dirtyfb ioctl.

Fix this by sending single update on every invalidate callback.

Signed-off-by: Jouni Högander <jouni.hogander at intel.com>
Fixes: 805f04d42a6b5f4187935b43c9c39ae03ccfa761 ("drm/i915/display/psr: Use continuos full frame to handle frontbuffer invalidations")
Cc: José Roberto de Souza <jose.souza at intel.com>
---
 drivers/gpu/drm/i915/display/intel_psr.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index 904a1049eff3..564d4fd94048 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -2209,8 +2209,11 @@ static void _psr_invalidate_handle(struct intel_dp *intel_dp)
 	if (intel_dp->psr.psr2_sel_fetch_enabled) {
 		u32 val;
 
-		if (intel_dp->psr.psr2_sel_fetch_cff_enabled)
+		if (intel_dp->psr.psr2_sel_fetch_cff_enabled) {
+			/* Send one update otherwise lag is observed in screen */
+			intel_de_write(dev_priv, CURSURFLIVE(intel_dp->psr.pipe), 0);
 			return;
+		}
 
 		val = man_trk_ctl_enable_bit_get(dev_priv) |
 		      man_trk_ctl_partial_frame_bit_get(dev_priv) |
-- 
2.34.1