/* Copyright 2021 Advanced Micro Devices, Inc. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors: AMD
 *
 */

#include "link_enc_cfg.h"
#include "resource.h"
#include "link_service.h"

#define DC_LOGGER dc->ctx->logger

/* Check whether stream is supported by DIG link encoders. */
static bool is_dig_link_enc_stream(struct dc_stream_state *stream)
{
        bool is_dig_stream = false;
        struct link_encoder *link_enc = NULL;
        unsigned int i;

        /* Loop over created link encoder objects. */
        if (stream) {
                for (i = 0; i < stream->ctx->dc->res_pool->res_cap->num_dig_link_enc; i++) {
                        link_enc = stream->ctx->dc->res_pool->link_encoders[i];

                        /* Need to check link signal type rather than stream signal type which may not
                         * yet match.
                         */
                        if (link_enc && ((uint32_t)stream->link->connector_signal & link_enc->output_signals)) {
                                is_dig_stream = true;
                                /* If stream is HDMI FRL, then it is not a DIG stream. */
                                if (dc_is_hdmi_frl_signal(stream->signal))
                                        is_dig_stream = false;
                                break;
                        }
                }
        }
        return is_dig_stream;
}

static struct link_enc_assignment get_assignment(struct dc *dc, int i)
{
        struct link_enc_assignment assignment;

        if (dc->current_state->res_ctx.link_enc_cfg_ctx.mode == LINK_ENC_CFG_TRANSIENT)
                assignment = dc->current_state->res_ctx.link_enc_cfg_ctx.transient_assignments[i];
        else /* LINK_ENC_CFG_STEADY */
                assignment = dc->current_state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i];

        return assignment;
}

/* Return stream using DIG link encoder resource. NULL if unused. */
static struct dc_stream_state *get_stream_using_link_enc(
                struct dc_state *state,
                enum engine_id eng_id)
{
        struct dc_stream_state *stream = NULL;
        int i;

        for (i = 0; i < state->stream_count; i++) {
                struct link_enc_assignment assignment = state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i];

                if ((assignment.valid == true) && (assignment.eng_id == eng_id)) {
                        stream = state->streams[i];
                        break;
                }
        }

        return stream;
}

static void remove_link_enc_assignment(
                struct dc_state *state,
                struct dc_stream_state *stream,
                enum engine_id eng_id)
{
        int eng_idx;
        int i;

        if (eng_id != ENGINE_ID_UNKNOWN) {
                eng_idx = eng_id - ENGINE_ID_DIGA;

                /* stream ptr of stream in dc_state used to update correct entry in
                 * link_enc_assignments table.
                 */
                for (i = 0; i < MAX_PIPES; i++) {
                        struct link_enc_assignment assignment = state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i];

                        if (assignment.valid && assignment.stream == stream) {
                                state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i].valid = false;
                                /* Only add link encoder back to availability pool if not being
                                 * used by any other stream (i.e. removing SST stream or last MST stream).
                                 */
                                if (get_stream_using_link_enc(state, eng_id) == NULL)
                                        state->res_ctx.link_enc_cfg_ctx.link_enc_avail[eng_idx] = eng_id;

                                stream->link_enc = NULL;
                                state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i].eng_id = ENGINE_ID_UNKNOWN;
                                state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i].stream = NULL;
                                dc_stream_release(stream);
                                break;
                        }
                }
        }
}

static void add_link_enc_assignment(
                struct dc_state *state,
                struct dc_stream_state *stream,
                enum engine_id eng_id)
{
        int eng_idx;
        int i;

        if (eng_id != ENGINE_ID_UNKNOWN) {
                eng_idx = eng_id - ENGINE_ID_DIGA;

                /* stream ptr of stream in dc_state used to update correct entry in
                 * link_enc_assignments table.
                 */
                for (i = 0; i < state->stream_count; i++) {
                        if (stream == state->streams[i]) {
                                state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i] = (struct link_enc_assignment){
                                        .valid = true,
                                        .ep_id = (struct display_endpoint_id) {
                                                .link_id = stream->link->link_id,
                                                .ep_type = stream->link->ep_type},
                                        .eng_id = eng_id,
                                        .stream = stream};
                                dc_stream_retain(stream);
                                state->res_ctx.link_enc_cfg_ctx.link_enc_avail[eng_idx] = ENGINE_ID_UNKNOWN;
                                stream->link_enc = stream->ctx->dc->res_pool->link_encoders[eng_idx];
                                break;
                        }
                }

                /* Attempted to add an encoder assignment for a stream not in dc_state. */
                ASSERT(i != state->stream_count);
        }
}

/* Return first available DIG link encoder. */
static enum engine_id find_first_avail_link_enc(
                const struct dc_context *ctx,
                const struct dc_state *state,
                enum engine_id eng_id_requested)
{
        enum engine_id eng_id = ENGINE_ID_UNKNOWN;
        unsigned int i;

        if (eng_id_requested != ENGINE_ID_UNKNOWN) {

                for (i = 0; i < ctx->dc->res_pool->res_cap->num_dig_link_enc; i++) {
                        eng_id = state->res_ctx.link_enc_cfg_ctx.link_enc_avail[i];
                        if (eng_id == eng_id_requested)
                                return eng_id;
                }
        }

        eng_id = ENGINE_ID_UNKNOWN;

        for (i = 0; i < ctx->dc->res_pool->res_cap->num_dig_link_enc; i++) {
                eng_id = state->res_ctx.link_enc_cfg_ctx.link_enc_avail[i];
                if (eng_id != ENGINE_ID_UNKNOWN)
                        break;
        }

        return eng_id;
}

/* Check for availability of link encoder eng_id. */
static bool is_avail_link_enc(struct dc_state *state, enum engine_id eng_id, struct dc_stream_state *stream)
{
        bool is_avail = false;
        int eng_idx = eng_id - ENGINE_ID_DIGA;

        /* An encoder is available if it is still in the availability pool. */
        if (eng_id != ENGINE_ID_UNKNOWN && state->res_ctx.link_enc_cfg_ctx.link_enc_avail[eng_idx] != ENGINE_ID_UNKNOWN) {
                is_avail = true;
        } else {
                struct dc_stream_state *stream_assigned = NULL;

                /* MST streams share the same link and should share the same encoder.
                 * If a stream that has already been assigned a link encoder uses as the
                 * same link as the stream checking for availability, it is an MST stream
                 * and should use the same link encoder.
                 */
                stream_assigned = get_stream_using_link_enc(state, eng_id);
                if (stream_assigned && stream != stream_assigned && stream->link == stream_assigned->link)
                        is_avail = true;
        }

        return is_avail;
}

/* Test for display_endpoint_id equality. */
static bool are_ep_ids_equal(struct display_endpoint_id *lhs, struct display_endpoint_id *rhs)
{
        bool are_equal = false;

        if (lhs->link_id.id == rhs->link_id.id &&
                        lhs->link_id.enum_id == rhs->link_id.enum_id &&
                        lhs->link_id.type == rhs->link_id.type &&
                        lhs->ep_type == rhs->ep_type)
                are_equal = true;

        return are_equal;
}

static struct link_encoder *get_link_enc_used_by_link(
                struct dc_state *state,
                const struct dc_link *link)
{
        struct link_encoder *link_enc = NULL;
        struct display_endpoint_id ep_id;
        int i;

        ep_id = (struct display_endpoint_id) {
                .link_id = link->link_id,
                .ep_type = link->ep_type};

        for (i = 0; i < MAX_PIPES; i++) {
                struct link_enc_assignment assignment = state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i];
                if (assignment.eng_id == ENGINE_ID_UNKNOWN)
                        continue;

                if (assignment.valid == true && are_ep_ids_equal(&assignment.ep_id, &ep_id))
                        link_enc = link->dc->res_pool->link_encoders[assignment.eng_id - ENGINE_ID_DIGA];
        }

        return link_enc;
}
/* Clear all link encoder assignments. */
static void clear_enc_assignments(const struct dc *dc, struct dc_state *state)
{
        unsigned int i;

        for (i = 0; i < MAX_PIPES; i++) {
                state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i].valid = false;
                state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i].eng_id = ENGINE_ID_UNKNOWN;
                if (state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i].stream != NULL) {
                        dc_stream_release(state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i].stream);
                        state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i].stream = NULL;
                }
        }

        for (i = 0; i < dc->res_pool->res_cap->num_dig_link_enc; i++) {
                if (dc->res_pool->link_encoders[i])
                        state->res_ctx.link_enc_cfg_ctx.link_enc_avail[i] = (enum engine_id) i;
                else
                        state->res_ctx.link_enc_cfg_ctx.link_enc_avail[i] = ENGINE_ID_UNKNOWN;
        }
}

void link_enc_cfg_init(
                const struct dc *dc,
                struct dc_state *state)
{
        clear_enc_assignments(dc, state);

        state->res_ctx.link_enc_cfg_ctx.mode = LINK_ENC_CFG_STEADY;
}

void link_enc_cfg_copy(const struct dc_state *src_ctx, struct dc_state *dst_ctx)
{
        memcpy(&dst_ctx->res_ctx.link_enc_cfg_ctx,
               &src_ctx->res_ctx.link_enc_cfg_ctx,
               sizeof(dst_ctx->res_ctx.link_enc_cfg_ctx));
}

void link_enc_cfg_link_encs_assign(
                struct dc *dc,
                struct dc_state *state,
                struct dc_stream_state *streams[],
                uint8_t stream_count)
{
        enum engine_id eng_id = ENGINE_ID_UNKNOWN, eng_id_req = ENGINE_ID_UNKNOWN;
        int i;
        int j;

        ASSERT(state->stream_count == stream_count);
        ASSERT(dc->current_state->res_ctx.link_enc_cfg_ctx.mode == LINK_ENC_CFG_STEADY);

        /* Release DIG link encoder resources before running assignment algorithm. */
        for (i = 0; i < dc->current_state->stream_count; i++)
                dc->res_pool->funcs->link_enc_unassign(state, dc->current_state->streams[i]);

        for (i = 0; i < MAX_PIPES; i++)
                ASSERT(state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i].valid == false);

        /* (a) Assign DIG link encoders to physical (unmappable) endpoints first. */
        for (i = 0; i < stream_count; i++) {
                struct dc_stream_state *stream = streams[i];

                /* skip it if the link is mappable endpoint. */
                if (stream->link->is_dig_mapping_flexible)
                        continue;

                /* Skip stream if not supported by DIG link encoder. */
                if (!is_dig_link_enc_stream(stream))
                        continue;

                /* Physical endpoints have a fixed mapping to DIG link encoders. */
                eng_id = stream->link->eng_id;
                add_link_enc_assignment(state, stream, eng_id);
        }

        /* (b) Retain previous assignments for mappable endpoints if encoders still available. */
        eng_id = ENGINE_ID_UNKNOWN;

        if (state != dc->current_state) {
                struct dc_state *prev_state = dc->current_state;

                for (i = 0; i < stream_count; i++) {
                        struct dc_stream_state *stream = state->streams[i];

                        /* Skip it if the link is NOT mappable endpoint. */
                        if (!stream->link->is_dig_mapping_flexible)
                                continue;

                        /* Skip stream if not supported by DIG link encoder. */
                        if (!is_dig_link_enc_stream(stream))
                                continue;

                        for (j = 0; j < prev_state->stream_count; j++) {
                                struct dc_stream_state *prev_stream = prev_state->streams[j];

                                if (stream == prev_stream && stream->link == prev_stream->link &&
                                                prev_state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[j].valid) {
                                        eng_id = prev_state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[j].eng_id;

                                        if (is_avail_link_enc(state, eng_id, stream))
                                                add_link_enc_assignment(state, stream, eng_id);
                                }
                        }
                }
        }

        /* (c) Then assign encoders to remaining mappable endpoints. */
        eng_id = ENGINE_ID_UNKNOWN;

        for (i = 0; i < stream_count; i++) {
                struct dc_stream_state *stream = streams[i];
                struct link_encoder *link_enc = NULL;

                /* Skip it if the link is NOT mappable endpoint. */
                if (!stream->link->is_dig_mapping_flexible)
                        continue;

                /* Skip if encoder assignment retained in step (b) above. */
                if (stream->link_enc)
                        continue;

                /* Skip stream if not supported by DIG link encoder. */
                if (!is_dig_link_enc_stream(stream)) {
                        ASSERT(stream->link->is_dig_mapping_flexible != true);
                        continue;
                }

                /* Mappable endpoints have a flexible mapping to DIG link encoders. */

                /* For MST, multiple streams will share the same link / display
                 * endpoint. These streams should use the same link encoder
                 * assigned to that endpoint.
                 */
                link_enc = get_link_enc_used_by_link(state, stream->link);
                if (link_enc == NULL) {

                        if (stream->link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA &&
                                        stream->link->dpia_preferred_eng_id != ENGINE_ID_UNKNOWN)
                                eng_id_req = stream->link->dpia_preferred_eng_id;

                        eng_id = find_first_avail_link_enc(stream->ctx, state, eng_id_req);
                }
                else
                        eng_id =  link_enc->preferred_engine;

                add_link_enc_assignment(state, stream, eng_id);
        }

        link_enc_cfg_validate(dc, state);

        /* Update transient assignments. */
        for (i = 0; i < MAX_PIPES; i++) {
                dc->current_state->res_ctx.link_enc_cfg_ctx.transient_assignments[i] =
                        state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i];
        }

        /* Log encoder assignments. */
        for (i = 0; i < MAX_PIPES; i++) {
                struct link_enc_assignment assignment =
                                dc->current_state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i];

                if (assignment.valid)
                        DC_LOG_DEBUG("%s: CUR %s(%d) - enc_id(%d)\n",
                                        __func__,
                                        assignment.ep_id.ep_type == DISPLAY_ENDPOINT_PHY ? "PHY" : "DPIA",
                                        assignment.ep_id.ep_type == DISPLAY_ENDPOINT_PHY ?
                                                        assignment.ep_id.link_id.enum_id :
                                                        assignment.ep_id.link_id.enum_id - 1,
                                        assignment.eng_id);
        }
        for (i = 0; i < MAX_PIPES; i++) {
                struct link_enc_assignment assignment =
                                state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i];

                if (assignment.valid)
                        DC_LOG_DEBUG("%s: NEW %s(%d) - enc_id(%d)\n",
                                        __func__,
                                        assignment.ep_id.ep_type == DISPLAY_ENDPOINT_PHY ? "PHY" : "DPIA",
                                        assignment.ep_id.ep_type == DISPLAY_ENDPOINT_PHY ?
                                                        assignment.ep_id.link_id.enum_id :
                                                        assignment.ep_id.link_id.enum_id - 1,
                                        assignment.eng_id);
        }

        /* Current state mode will be set to steady once this state committed. */
        state->res_ctx.link_enc_cfg_ctx.mode = LINK_ENC_CFG_STEADY;
}

void link_enc_cfg_link_enc_unassign(
                struct dc_state *state,
                struct dc_stream_state *stream)
{
        enum engine_id eng_id = ENGINE_ID_UNKNOWN;

        if (stream->link_enc)
                eng_id = stream->link_enc->preferred_engine;

        remove_link_enc_assignment(state, stream, eng_id);
}

bool link_enc_cfg_is_transmitter_mappable(
                struct dc *dc,
                struct link_encoder *link_enc)
{
        bool is_mappable = false;
        enum engine_id eng_id = link_enc->preferred_engine;
        struct dc_stream_state *stream = link_enc_cfg_get_stream_using_link_enc(dc, eng_id);

        if (stream)
                is_mappable = stream->link->is_dig_mapping_flexible;

        return is_mappable;
}

struct dc_stream_state *link_enc_cfg_get_stream_using_link_enc(
                struct dc *dc,
                enum engine_id eng_id)
{
        struct dc_stream_state *stream = NULL;
        int i;

        for (i = 0; i < MAX_PIPES; i++) {
                struct link_enc_assignment assignment = get_assignment(dc, i);

                if ((assignment.valid == true) && (assignment.eng_id == eng_id)) {
                        stream = assignment.stream;
                        break;
                }
        }

        return stream;
}

struct dc_link *link_enc_cfg_get_link_using_link_enc(
                struct dc *dc,
                enum engine_id eng_id)
{
        struct dc_link *link = NULL;
        struct dc_stream_state *stream = NULL;

        stream = link_enc_cfg_get_stream_using_link_enc(dc, eng_id);

        if (stream)
                link = stream->link;

        return link;
}

struct link_encoder *link_enc_cfg_get_link_enc_used_by_link(
                struct dc *dc,
                const struct dc_link *link)
{
        struct link_encoder *link_enc = NULL;
        struct display_endpoint_id ep_id;
        int i;

        ep_id = (struct display_endpoint_id) {
                .link_id = link->link_id,
                .ep_type = link->ep_type};

        for (i = 0; i < MAX_PIPES; i++) {
                struct link_enc_assignment assignment = get_assignment(dc, i);
                if (assignment.eng_id == ENGINE_ID_UNKNOWN)
                        continue;

                if (assignment.valid == true && are_ep_ids_equal(&assignment.ep_id, &ep_id)) {
                        link_enc = link->dc->res_pool->link_encoders[assignment.eng_id - ENGINE_ID_DIGA];
                        break;
                }
        }

        return link_enc;
}

struct link_encoder *link_enc_cfg_get_next_avail_link_enc(struct dc *dc)
{
        struct link_encoder *link_enc = NULL;
        enum engine_id encs_assigned[MAX_LINK_ENCODERS];
        unsigned int i;

        for (i = 0; i < MAX_LINK_ENCODERS; i++)
                encs_assigned[i] = ENGINE_ID_UNKNOWN;

        /* Add assigned encoders to list. */
        for (i = 0; i < MAX_PIPES; i++) {
                struct link_enc_assignment assignment = get_assignment(dc, i);

                if (assignment.valid && assignment.eng_id != ENGINE_ID_UNKNOWN)
                        encs_assigned[assignment.eng_id - ENGINE_ID_DIGA] = assignment.eng_id;
        }

        for (i = 0; i < dc->res_pool->res_cap->num_dig_link_enc; i++) {
                if (encs_assigned[i] == ENGINE_ID_UNKNOWN &&
                                dc->res_pool->link_encoders[i] != NULL) {
                        link_enc = dc->res_pool->link_encoders[i];
                        break;
                }
        }

        return link_enc;
}

struct link_encoder *link_enc_cfg_get_link_enc(
                const struct dc_link *link)
{
        struct link_encoder *link_enc = NULL;

        /* Links supporting dynamically assigned link encoder will be assigned next
         * available encoder if one not already assigned.
         */
        if (link->is_dig_mapping_flexible &&
            link->dc->res_pool->funcs->link_encs_assign) {
                link_enc = link_enc_cfg_get_link_enc_used_by_link(link->ctx->dc, link);
                if (link_enc == NULL)
                        link_enc = link_enc_cfg_get_next_avail_link_enc(
                                link->ctx->dc);
        } else
                link_enc = link->link_enc;

        return link_enc;
}

struct link_encoder *link_enc_cfg_get_link_enc_used_by_stream_current(
                struct dc *dc,
                const struct dc_stream_state *stream)
{
        struct link_encoder *link_enc = NULL;
        struct display_endpoint_id ep_id;
        int i;

        ep_id = (struct display_endpoint_id) {
                .link_id = stream->link->link_id,
                .ep_type = stream->link->ep_type};

        for (i = 0; i < MAX_PIPES; i++) {
                struct link_enc_assignment assignment =
                        dc->current_state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i];

                if (assignment.eng_id == ENGINE_ID_UNKNOWN)
                        continue;

                if (assignment.valid == true && are_ep_ids_equal(&assignment.ep_id, &ep_id)) {
                        link_enc = stream->link->dc->res_pool->link_encoders[assignment.eng_id - ENGINE_ID_DIGA];
                        break;
                }
        }

        return link_enc;
}

bool link_enc_cfg_is_link_enc_avail(struct dc *dc, enum engine_id eng_id, struct dc_link *link)
{
        bool is_avail = true;
        int i;

        /* An encoder is not available if it has already been assigned to a different endpoint. */
        for (i = 0; i < MAX_PIPES; i++) {
                struct link_enc_assignment assignment = get_assignment(dc, i);
                struct display_endpoint_id ep_id = (struct display_endpoint_id) {
                                .link_id = link->link_id,
                                .ep_type = link->ep_type};

                if (assignment.valid && assignment.eng_id == eng_id && !are_ep_ids_equal(&ep_id, &assignment.ep_id)) {
                        is_avail = false;
                        break;
                }
        }

        return is_avail;
}

bool link_enc_cfg_validate(struct dc *dc, struct dc_state *state)
{
        bool is_valid = false;
        bool valid_entries = true;
        bool valid_stream_ptrs = true;
        bool valid_uniqueness = true;
        bool valid_avail = true;
        bool valid_streams = true;
        int i;
        unsigned int j;
        uint8_t valid_count = 0;
        uint8_t dig_stream_count = 0;
        int eng_ids_per_ep_id[MAX_PIPES] = {0};
        int ep_ids_per_eng_id[MAX_PIPES] = {0};
        int valid_bitmap = 0;

        /* (1) No. valid entries same as stream count. */
        for (i = 0; i < MAX_PIPES; i++) {
                struct link_enc_assignment assignment = state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i];

                if (assignment.valid)
                        valid_count++;

                if (is_dig_link_enc_stream(state->streams[i]))
                        dig_stream_count++;
        }
        if (valid_count != dig_stream_count)
                valid_entries = false;

        /* (2) Matching stream ptrs. */
        for (i = 0; i < MAX_PIPES; i++) {
                struct link_enc_assignment assignment = state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i];

                if (assignment.valid) {
                        if (assignment.stream != state->streams[i])
                                valid_stream_ptrs = false;
                }
        }

        /* (3) Each endpoint assigned unique encoder. */
        for (i = 0; i < MAX_PIPES; i++) {
                struct link_enc_assignment assignment_i = state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i];

                if (assignment_i.valid) {
                        struct display_endpoint_id ep_id_i = assignment_i.ep_id;

                        eng_ids_per_ep_id[i]++;
                        ep_ids_per_eng_id[i]++;
                        for (j = 0; j < MAX_PIPES; j++) {
                                struct link_enc_assignment assignment_j =
                                        state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[j];

                                if (j == i)
                                        continue;

                                if (assignment_j.valid) {
                                        struct display_endpoint_id ep_id_j = assignment_j.ep_id;

                                        if (are_ep_ids_equal(&ep_id_i, &ep_id_j) &&
                                                        assignment_i.eng_id != assignment_j.eng_id) {
                                                valid_uniqueness = false;
                                                eng_ids_per_ep_id[i]++;
                                        } else if (!are_ep_ids_equal(&ep_id_i, &ep_id_j) &&
                                                        assignment_i.eng_id == assignment_j.eng_id) {
                                                valid_uniqueness = false;
                                                ep_ids_per_eng_id[i]++;
                                        }
                                }
                        }
                }
        }

        /* (4) Assigned encoders not in available pool. */
        for (i = 0; i < MAX_PIPES; i++) {
                struct link_enc_assignment assignment = state->res_ctx.link_enc_cfg_ctx.link_enc_assignments[i];

                if (assignment.valid) {
                        for (j = 0; j < dc->res_pool->res_cap->num_dig_link_enc; j++) {
                                if (state->res_ctx.link_enc_cfg_ctx.link_enc_avail[j] == assignment.eng_id) {
                                        valid_avail = false;
                                        break;
                                }
                        }
                }
        }

        /* (5) All streams have valid link encoders. */
        for (i = 0; i < state->stream_count; i++) {
                struct dc_stream_state *stream = state->streams[i];

                if (is_dig_link_enc_stream(stream) && stream->link_enc == NULL) {
                        valid_streams = false;
                        break;
                }
        }

        is_valid = valid_entries && valid_stream_ptrs && valid_uniqueness && valid_avail && valid_streams;
        ASSERT(is_valid);

        if (is_valid == false) {
                valid_bitmap =
                        (valid_entries & 0x1) |
                        ((valid_stream_ptrs & 0x1) << 1) |
                        ((valid_uniqueness & 0x1) << 2) |
                        ((valid_avail & 0x1) << 3) |
                        ((valid_streams & 0x1) << 4);
                DC_LOG_ERROR("%s: Invalid link encoder assignments - 0x%x\n", __func__, valid_bitmap);
        }

        return is_valid;
}

void link_enc_cfg_set_transient_mode(struct dc *dc, struct dc_state *current_state, struct dc_state *new_state)
{
        int i = 0;
        int num_transient_assignments = 0;

        for (i = 0; i < MAX_PIPES; i++) {
                if (current_state->res_ctx.link_enc_cfg_ctx.transient_assignments[i].valid)
                        num_transient_assignments++;
        }

        /* Only enter transient mode if the new encoder assignments are valid. */
        if (new_state->stream_count == num_transient_assignments) {
                current_state->res_ctx.link_enc_cfg_ctx.mode = LINK_ENC_CFG_TRANSIENT;
                DC_LOG_DEBUG("%s: current_state(%p) mode(%d)\n", __func__, current_state, LINK_ENC_CFG_TRANSIENT);
        }
}