On Wed, 2018-03-07 at 15:34 -0800, Dhinakaran Pandiyan wrote: > On Wed, 2018-03-07 at 22:53 +0000, Chris Wilson wrote: > > Quoting Dhinakaran Pandiyan (2018-03-07 03:34:19) > > > DRM_IOCTL_MODE_CURSOR results in frontbuffer flush before the cursor > > > plane MMIOs are written to. But this flush should not be necessary for > > > PSR as hardware tracking triggers PSR exit when MMIOs are written. As > > > for FBC, the spec says "Flips or changes to plane size and panning" cause > > > FBC to be nuked. Use origin == ORIGIN_FLIP so that features can ignore > > > cursor updates in their frontbuffer_flush implementations. > > > > > > /sys/kernel/debug/dri/0/i915_fbc_status shows > > > "Compressing: yes" when I move the cursor around. > > > > > > v3: Use ORIGIN_FLIP now that pin_to_display does not flush frontbuffer. > > > v2: Update comment in i915_gem_object_pin_to_display_plane. (Chris) > > > > > > Cc: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx> > > > Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > > Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > > Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> > > > Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@xxxxxxxxx> > > > --- > > > drivers/gpu/drm/i915/intel_display.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c > > > index 91ce8a0522a3..18b08e263ee1 100644 > > > --- a/drivers/gpu/drm/i915/intel_display.c > > > +++ b/drivers/gpu/drm/i915/intel_display.c > > > @@ -13176,7 +13176,7 @@ intel_legacy_cursor_update(struct drm_plane *plane, > > > if (ret) > > > goto out_unlock; > > > > > > - intel_fb_obj_flush(intel_fb_obj(fb), ORIGIN_DIRTYFB); > > > + intel_fb_obj_flush(intel_fb_obj(fb), ORIGIN_FLIP); > > > > What about prepare_plane? That should reduce to ORIGIN_FLIP as well, > > aiui. > > -Chris > > > That was the idea but there's a problem with not knowing if PSR exit is > fully complete before we begin updating the plane registers in > pipe_update_start(). > > Let's say PSR was active and display is in DC6. A flip comes in, without > _flush(DIRTYFB) in prepare_plane_fb(), PSR exit is delayed until vblank > enabling that happens in pipe_update_start. Correction, _flush(DIRTYFB) in prepare_plane_fb() has no effect because the gem object has no frontbuffer bits set. We should just remove that misleading call. > We immediately follow that > with programming the plane MMIO's without checking if PSR fully exited. > If PSR and DC6 happen to exit while we were in the middle of programming > plane MMIO's, the resulting vblank toggle (from PSR exit) might activate > partially programmed registers. _flush(DIRTYFB) gives us an opportunity > to exit PSR fully by starting early. > > As for legacy_cursor_update(), since there is no vblank enabling > involved, we avoid updating the MMIO's in the midst of PSR exit > > > > _______________________________________________ > > Intel-gfx mailing list > > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > > https://lists.freedesktop.org/mailman/listinfo/intel-gfx _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
