On Wed, Mar 07, 2018 at 04:21:53PM -0800, Pandiyan, Dhinakaran wrote: > On Wed, 2018-03-07 at 15:43 -0800, Rodrigo Vivi wrote: > > On Wed, Mar 07, 2018 at 03:23:13PM -0800, Rodrigo Vivi wrote: > > > On Wed, Mar 07, 2018 at 11:10:35PM +0000, Pandiyan, Dhinakaran 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. 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 > > > > > > I don't believe you will be ever in a case that you write to any register > > > and get any flip or anything without exiting DC6 before that happens. > > > > > > Or the CSR mechanism of DC6 will be simply wrong. > > > > > > Would this be enough? > > > > ok... just ignore my previous comment... > > I believe we can move with the safest side and maybe revisit this later. > > > > From what I remember of the FBC nuke needs as well I believe this is > > the right move. > > > > Although I'm asking myself now if we are not changing the meaning of the > > ORIGINS here. Shouldn't we add a new origin and update the handling? > > > > of "flip" is a good description for this call? > > > > The action taken for this frontbuffer_flush() is the same as origin == > FLIP. I think it is better to add a new one when we want the features > (psr,fbc) to distinguish and react differently. Maybe we could change the names from ORIGIN_something to something more meaninful about the operation to be performed then... Anyways I don't want to force increase the number of origins and duplicate the code on a niptic and I don't have better suggestions for names... So I guess we move fwd with this for now... Reviewed-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> > > > > > > > > > > > > > > > > > > _______________________________________________ > > > > > 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 > > > _______________________________________________ > > > 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
