On Mon, 2022-10-24 at 08:46 +0300, Jouni Högander wrote:
> Currently we are observing mouse cursor stuttering when using
> xrandr --scaling=1.2x1.2. X scaling/transformation seems to be
> doing fronbuffer rendering. When moving mouse cursor X seems to
> perform several invalidates and only one DirtyFB. I.e. it seems
> to be assuming updates are sent to panel while drawing is done.
>
> Earlier we were disabling PSR in frontbuffer invalidate call back
> (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. It just configures PSR to send full frame
> when updates are sent. 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.
Fair enough.
Reviewed-by: José Roberto de Souza <jose.souza@xxxxxxxxx>
>
> Cc: José Roberto de Souza <jose.souza@xxxxxxxxx>
> Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> Cc: Mika Kahola <mika.kahola@xxxxxxxxx>
>
> Fixes: 805f04d42a6b ("drm/i915/display/psr: Use continuos full frame to handle frontbuffer invalidations")
> Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6679
> Signed-off-by: Jouni Högander <jouni.hogander@xxxxxxxxx>
> Reported-by: Brian J. Tarricone <brian@xxxxxxxxxxxxx>
> Tested-by: Brian J. Tarricone <brian@xxxxxxxxxxxxx>
> ---
> 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) |
