On Mon, Feb 06, 2023 at 07:42:32PM -0500, Lyude Paul wrote:
> On Wed, 2023-02-01 at 17:04 +0200, Imre Deak wrote:
> >
> > Yes, this patch should have no functional change, so please check what
> > would apply to other drivers as well.
> >
> > Could you also check Ville's comment about storing start_slot elsewhere
> > than the atomic state (leaving only time_slots there). I wonder if that
> > would work, at least it would simplify things I think.
>
> Ideally it'd be nice if we could have all this info in the atomic commit, but
> yeah - you're not the first person to find this a bit confusing. FWIW though,
> the way we store start_slot right now is intended to follow the same kind of
> behavior we have with atomic CRTC commit dependencies, I think I also made it
> that way so all of the state would be in a single place but there's no hard
> requirement for it.
As I understood the atomic state should be precomputed during atomic
check and not changed later during the commit phase. In case of
start_slot this would mean knowing in advance the actual (driver
specific) disabling / enabling sequence of the payloads, not sure how
feasible it is to figure that out. start_slot also changes dynamically
as each payload is disabled, so these intermediate versions of the field
would need to be tracked somehow separately from the final (precomputed)
versions.
> So if you guys think it'd be better design-wise to store this something else,
> I've got no strong feelings either way
> >
> > > For 0-2:
> > >
> > > Reviewed-by: Lyude Paul <ly...@redhat.com>
> >
> > Thanks.
> >
> > >
> > > >
> > > > Cc: Lyude Paul <ly...@redhat.com>
> > > > Cc: Ville Syrjälä <ville.syrj...@linux.intel.com>
> > > > Cc: Ben Skeggs <bske...@redhat.com>
> > > > Cc: Karol Herbst <kher...@redhat.com>
> > > > Cc: Harry Wentland <harry.wentl...@amd.com>
> > > > Cc: Alex Deucher <alexander.deuc...@amd.com>
> > > > Cc: Wayne Lin <wayne....@amd.com>
> > > > Cc: sta...@vger.kernel.org # 6.1
> > > > Cc: dri-de...@lists.freedesktop.org
> > > > Reviewed-by: Ville Syrjälä <ville.syrj...@linux.intel.com>
> > > > Signed-off-by: Imre Deak <imre.d...@intel.com>
> > > > ---
> > > > .../amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 2 +-
> > > > drivers/gpu/drm/display/drm_dp_mst_topology.c | 26 ++++++++++---------
> > > > drivers/gpu/drm/i915/display/intel_dp_mst.c | 4 ++-
> > > > drivers/gpu/drm/nouveau/dispnv50/disp.c | 2 +-
> > > > include/drm/display/drm_dp_mst_helper.h | 3 ++-
> > > > 5 files changed, 21 insertions(+), 16 deletions(-)
> > > >
> > > > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> > > > b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> > > > index a50319fc42b11..180d3893b68da 100644
> > > > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> > > > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> > > > @@ -208,7 +208,7 @@ bool
> > > > dm_helpers_dp_mst_write_payload_allocation_table(
> > > > if (enable)
> > > > drm_dp_add_payload_part1(mst_mgr, mst_state, payload);
> > > > else
> > > > - drm_dp_remove_payload(mst_mgr, mst_state, payload);
> > > > + drm_dp_remove_payload(mst_mgr, mst_state, payload,
> > > > payload);
> > > >
> > > > /* mst_mgr->->payloads are VC payload notify MST branch using
> > > > DPCD or
> > > > * AUX message. The sequence is slot 1-63 allocated sequence
> > > > for each
> > > > diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c
> > > > b/drivers/gpu/drm/display/drm_dp_mst_topology.c
> > > > index 847c10aa2098c..1990ff5dc7ddd 100644
> > > > --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c
> > > > +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c
> > > > @@ -3342,7 +3342,8 @@ EXPORT_SYMBOL(drm_dp_add_payload_part1);
> > > > * drm_dp_remove_payload() - Remove an MST payload
> > > > * @mgr: Manager to use.
> > > > * @mst_state: The MST atomic state
> > > > - * @payload: The payload to write
> > > > + * @old_payload: The payload with its old state
> > > > + * @new_payload: The payload to write
> > > > *
> > > > * Removes a payload from an MST topology if it was successfully
> > > > assigned a start slot. Also updates
> > > > * the starting time slots of all other payloads which would have been
> > > > shifted towards the start of
> > > > @@ -3350,36 +3351,37 @@ EXPORT_SYMBOL(drm_dp_add_payload_part1);
> > > > */
> > > > void drm_dp_remove_payload(struct drm_dp_mst_topology_mgr *mgr,
> > > > struct drm_dp_mst_topology_state *mst_state,
> > > > - struct drm_dp_mst_atomic_payload *payload)
> > > > + const struct drm_dp_mst_atomic_payload
> > > > *old_payload,
> > > > + struct drm_dp_mst_atomic_payload
> > > > *new_payload)
> > > > {
> > > > struct drm_dp_mst_atomic_payload *pos;
> > > > bool send_remove = false;
> > > >
> > > > /* We failed to make the payload, so nothing to do */
> > > > - if (payload->vc_start_slot == -1)
> > > > + if (new_payload->vc_start_slot == -1)
> > > > return;
> > > >
> > > > mutex_lock(&mgr->lock);
> > > > - send_remove =
> > > > drm_dp_mst_port_downstream_of_branch(payload->port, mgr->mst_primary);
> > > > + send_remove =
> > > > drm_dp_mst_port_downstream_of_branch(new_payload->port,
> > > > mgr->mst_primary);
> > > > mutex_unlock(&mgr->lock);
> > > >
> > > > if (send_remove)
> > > > - drm_dp_destroy_payload_step1(mgr, mst_state, payload);
> > > > + drm_dp_destroy_payload_step1(mgr, mst_state,
> > > > new_payload);
> > > > else
> > > > drm_dbg_kms(mgr->dev, "Payload for VCPI %d not in
> > > > topology, not sending remove\n",
> > > > - payload->vcpi);
> > > > + new_payload->vcpi);
> > > >
> > > > list_for_each_entry(pos, &mst_state->payloads, next) {
> > > > - if (pos != payload && pos->vc_start_slot >
> > > > payload->vc_start_slot)
> > > > - pos->vc_start_slot -= payload->time_slots;
> > > > + if (pos != new_payload && pos->vc_start_slot >
> > > > new_payload->vc_start_slot)
> > > > + pos->vc_start_slot -= old_payload->time_slots;
> > > > }
> > > > - payload->vc_start_slot = -1;
> > > > + new_payload->vc_start_slot = -1;
> > > >
> > > > mgr->payload_count--;
> > > > - mgr->next_start_slot -= payload->time_slots;
> > > > + mgr->next_start_slot -= old_payload->time_slots;
> > > >
> > > > - if (payload->delete)
> > > > - drm_dp_mst_put_port_malloc(payload->port);
> > > > + if (new_payload->delete)
> > > > + drm_dp_mst_put_port_malloc(new_payload->port);
> > > > }
> > > > EXPORT_SYMBOL(drm_dp_remove_payload);
> > > >
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > > > b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > > > index f3cb12dcfe0a7..dc4e5ff1dbb31 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > > > @@ -526,6 +526,8 @@ static void intel_mst_disable_dp(struct
> > > > intel_atomic_state *state,
> > > > to_intel_connector(old_conn_state->connector);
> > > > struct drm_dp_mst_topology_state *mst_state =
> > > > drm_atomic_get_mst_topology_state(&state->base,
> > > > &intel_dp->mst_mgr);
> > > > + struct drm_dp_mst_atomic_payload *payload =
> > > > + drm_atomic_get_mst_payload_state(mst_state,
> > > > connector->port);
> > > > struct drm_i915_private *i915 = to_i915(connector->base.dev);
> > > >
> > > > drm_dbg_kms(&i915->drm, "active links %d\n",
> > > > @@ -534,7 +536,7 @@ static void intel_mst_disable_dp(struct
> > > > intel_atomic_state *state,
> > > > intel_hdcp_disable(intel_mst->connector);
> > > >
> > > > drm_dp_remove_payload(&intel_dp->mst_mgr, mst_state,
> > > > -
> > > > drm_atomic_get_mst_payload_state(mst_state, connector->port));
> > > > + payload, payload);
> > > >
> > > > intel_audio_codec_disable(encoder, old_crtc_state,
> > > > old_conn_state);
> > > > }
> > > > diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c
> > > > b/drivers/gpu/drm/nouveau/dispnv50/disp.c
> > > > index edcb2529b4025..ed9d374147b8d 100644
> > > > --- a/drivers/gpu/drm/nouveau/dispnv50/disp.c
> > > > +++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c
> > > > @@ -885,7 +885,7 @@ nv50_msto_prepare(struct drm_atomic_state *state,
> > > >
> > > > // TODO: Figure out if we want to do a better job of handling
> > > > VCPI allocation failures here?
> > > > if (msto->disabled) {
> > > > - drm_dp_remove_payload(mgr, mst_state, payload);
> > > > + drm_dp_remove_payload(mgr, mst_state, payload, payload);
> > > >
> > > > nvif_outp_dp_mst_vcpi(&mstm->outp->outp,
> > > > msto->head->base.index, 0, 0, 0, 0);
> > > > } else {
> > > > diff --git a/include/drm/display/drm_dp_mst_helper.h
> > > > b/include/drm/display/drm_dp_mst_helper.h
> > > > index 41fd8352ab656..f5eb9aa152b14 100644
> > > > --- a/include/drm/display/drm_dp_mst_helper.h
> > > > +++ b/include/drm/display/drm_dp_mst_helper.h
> > > > @@ -841,7 +841,8 @@ int drm_dp_add_payload_part2(struct
> > > > drm_dp_mst_topology_mgr *mgr,
> > > > struct drm_dp_mst_atomic_payload *payload);
> > > > void drm_dp_remove_payload(struct drm_dp_mst_topology_mgr *mgr,
> > > > struct drm_dp_mst_topology_state *mst_state,
> > > > - struct drm_dp_mst_atomic_payload *payload);
> > > > + const struct drm_dp_mst_atomic_payload
> > > > *old_payload,
> > > > + struct drm_dp_mst_atomic_payload
> > > > *new_payload);
> > > >
> > > > int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr);
> > > >
> > >
> > > --
> > > Cheers,
> > > Lyude Paul (she/her)
> > > Software Engineer at Red Hat
> > >
> >
>
> --
> Cheers,
> Lyude Paul (she/her)
> Software Engineer at Red Hat
>
