On Tue, Jan 31, 2023 at 06:13:10PM -0500, Lyude Paul wrote:
On Tue, 2023-01-31 at 17:05 +0200, Imre Deak wrote:
Atm, drm_dp_remove_payload() uses the same payload state to both get the vc_start_slot required for the payload removal DPCD message and to deduct time_slots from vc_start_slot of all payloads after the one being removed.
The above isn't always correct, as vc_start_slot must be the up-to-date version contained in the new payload state, but time_slots must be the one used when the payload was previously added, contained in the old payload state. The new payload's time_slots can change vs. the old one if the current atomic commit changes the corresponding mode.
This patch let's drivers pass the old and new payload states to drm_dp_remove_payload(), but keeps these the same for now in all drivers not to change the behavior. A follow-up i915 patch will pass in that driver the correct old and new states to the function.
Oh wow, this was definitely a mistake on my part, thanks for catching this! TBH, I think this behavior is correct so (now that I actually have a setup capable of testing amdgpu's MST fully thanks to gitlab issue 2171…) if you'd like to change it on other drivers as well I can test it fully.
I only checked that the other drivers pass the new payload state to drm_dp_remove_payload(), so not sure how that works atm if the same commit has to both remove the payload (with the old time_slots value) and add it back (with a new time_slots value). Maybe that can't happen in those drivers, or time_slots get updated between remove and readd.
Or feel free to leave it to me, shouldn't be too difficult I think :).
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.
For 0-2:
Reviewed-by: Lyude Paul lyude@redhat.com
Thanks.
Cc: Lyude Paul lyude@redhat.com Cc: Ville Syrjälä ville.syrjala@linux.intel.com Cc: Ben Skeggs bskeggs@redhat.com Cc: Karol Herbst kherbst@redhat.com Cc: Harry Wentland harry.wentland@amd.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Wayne Lin Wayne.Lin@amd.com Cc: stable@vger.kernel.org # 6.1 Cc: dri-devel@lists.freedesktop.org Reviewed-by: Ville Syrjälä ville.syrjala@linux.intel.com Signed-off-by: Imre Deak imre.deak@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);
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);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