diff options
Diffstat (limited to 'drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c')
-rw-r--r-- | drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c | 379 |
1 files changed, 222 insertions, 157 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c index 7581023daa..5491b707ce 100644 --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c @@ -50,15 +50,28 @@ static bool get_bw_alloc_proceed_flag(struct dc_link *tmp) && tmp->hpd_status && tmp->dpia_bw_alloc_config.bw_alloc_enabled); } + static void reset_bw_alloc_struct(struct dc_link *link) { link->dpia_bw_alloc_config.bw_alloc_enabled = false; - link->dpia_bw_alloc_config.sink_verified_bw = 0; - link->dpia_bw_alloc_config.sink_max_bw = 0; + link->dpia_bw_alloc_config.link_verified_bw = 0; + link->dpia_bw_alloc_config.link_max_bw = 0; + link->dpia_bw_alloc_config.allocated_bw = 0; link->dpia_bw_alloc_config.estimated_bw = 0; link->dpia_bw_alloc_config.bw_granularity = 0; + link->dpia_bw_alloc_config.dp_overhead = 0; link->dpia_bw_alloc_config.response_ready = false; + link->dpia_bw_alloc_config.nrd_max_lane_count = 0; + link->dpia_bw_alloc_config.nrd_max_link_rate = 0; + for (int i = 0; i < MAX_SINKS_PER_LINK; i++) + link->dpia_bw_alloc_config.remote_sink_req_bw[i] = 0; + DC_LOG_DEBUG("reset usb4 bw alloc of link(%d)\n", link->link_index); } + +#define BW_GRANULARITY_0 4 // 0.25 Gbps +#define BW_GRANULARITY_1 2 // 0.5 Gbps +#define BW_GRANULARITY_2 1 // 1 Gbps + static uint8_t get_bw_granularity(struct dc_link *link) { uint8_t bw_granularity = 0; @@ -71,16 +84,20 @@ static uint8_t get_bw_granularity(struct dc_link *link) switch (bw_granularity & 0x3) { case 0: - bw_granularity = 4; + bw_granularity = BW_GRANULARITY_0; break; case 1: + bw_granularity = BW_GRANULARITY_1; + break; + case 2: default: - bw_granularity = 2; + bw_granularity = BW_GRANULARITY_2; break; } return bw_granularity; } + static int get_estimated_bw(struct dc_link *link) { uint8_t bw_estimated_bw = 0; @@ -93,31 +110,33 @@ static int get_estimated_bw(struct dc_link *link) return bw_estimated_bw * (Kbps_TO_Gbps / link->dpia_bw_alloc_config.bw_granularity); } -static bool allocate_usb4_bw(int *stream_allocated_bw, int bw_needed, struct dc_link *link) + +static int get_non_reduced_max_link_rate(struct dc_link *link) { - if (bw_needed > 0) - *stream_allocated_bw += bw_needed; + uint8_t nrd_max_link_rate = 0; - return true; + core_link_read_dpcd( + link, + DP_TUNNELING_MAX_LINK_RATE, + &nrd_max_link_rate, + sizeof(uint8_t)); + + return nrd_max_link_rate; } -static bool deallocate_usb4_bw(int *stream_allocated_bw, int bw_to_dealloc, struct dc_link *link) -{ - bool ret = false; - if (*stream_allocated_bw > 0) { - *stream_allocated_bw -= bw_to_dealloc; - ret = true; - } else { - //Do nothing for now - ret = true; - } +static int get_non_reduced_max_lane_count(struct dc_link *link) +{ + uint8_t nrd_max_lane_count = 0; - // Unplug so reset values - if (!link->hpd_status) - reset_bw_alloc_struct(link); + core_link_read_dpcd( + link, + DP_TUNNELING_MAX_LANE_COUNT, + &nrd_max_lane_count, + sizeof(uint8_t)); - return ret; + return nrd_max_lane_count; } + /* * Read all New BW alloc configuration ex: estimated_bw, allocated_bw, * granuality, Driver_ID, CM_Group, & populate the BW allocation structs @@ -125,10 +144,22 @@ static bool deallocate_usb4_bw(int *stream_allocated_bw, int bw_to_dealloc, stru */ static void init_usb4_bw_struct(struct dc_link *link) { - // Init the known values + reset_bw_alloc_struct(link); + + /* init the known values */ link->dpia_bw_alloc_config.bw_granularity = get_bw_granularity(link); link->dpia_bw_alloc_config.estimated_bw = get_estimated_bw(link); + link->dpia_bw_alloc_config.nrd_max_link_rate = get_non_reduced_max_link_rate(link); + link->dpia_bw_alloc_config.nrd_max_lane_count = get_non_reduced_max_lane_count(link); + + DC_LOG_DEBUG("%s: bw_granularity(%d), estimated_bw(%d)\n", + __func__, link->dpia_bw_alloc_config.bw_granularity, + link->dpia_bw_alloc_config.estimated_bw); + DC_LOG_DEBUG("%s: nrd_max_link_rate(%d), nrd_max_lane_count(%d)\n", + __func__, link->dpia_bw_alloc_config.nrd_max_link_rate, + link->dpia_bw_alloc_config.nrd_max_lane_count); } + static uint8_t get_lowest_dpia_index(struct dc_link *link) { const struct dc *dc_struct = link->dc; @@ -141,51 +172,66 @@ static uint8_t get_lowest_dpia_index(struct dc_link *link) dc_struct->links[i]->ep_type != DISPLAY_ENDPOINT_USB4_DPIA) continue; - if (idx > dc_struct->links[i]->link_index) + if (idx > dc_struct->links[i]->link_index) { idx = dc_struct->links[i]->link_index; + break; + } } return idx; } + /* - * Get the Max Available BW or Max Estimated BW for each Host Router + * Get the maximum dp tunnel banwidth of host router * - * @link: pointer to the dc_link struct instance - * @type: ESTIMATD BW or MAX AVAILABLE BW + * @dc: pointer to the dc struct instance + * @hr_index: host router index * - * return: response_ready flag from dc_link struct + * return: host router maximum dp tunnel bandwidth */ -static int get_host_router_total_bw(struct dc_link *link, uint8_t type) +static int get_host_router_total_dp_tunnel_bw(const struct dc *dc, uint8_t hr_index) { - const struct dc *dc_struct = link->dc; - uint8_t lowest_dpia_index = get_lowest_dpia_index(link); - uint8_t idx = (link->link_index - lowest_dpia_index) / 2, idx_temp = 0; - struct dc_link *link_temp; + uint8_t lowest_dpia_index = get_lowest_dpia_index(dc->links[0]); + uint8_t hr_index_temp = 0; + struct dc_link *link_dpia_primary, *link_dpia_secondary; int total_bw = 0; - int i; - - for (i = 0; i < MAX_PIPES * 2; ++i) { - if (!dc_struct->links[i] || dc_struct->links[i]->ep_type != DISPLAY_ENDPOINT_USB4_DPIA) - continue; + for (uint8_t i = 0; i < (MAX_PIPES * 2) - 1; ++i) { - link_temp = dc_struct->links[i]; - if (!link_temp || !link_temp->hpd_status) + if (!dc->links[i] || dc->links[i]->ep_type != DISPLAY_ENDPOINT_USB4_DPIA) continue; - idx_temp = (link_temp->link_index - lowest_dpia_index) / 2; - - if (idx_temp == idx) { - - if (type == HOST_ROUTER_BW_ESTIMATED) - total_bw += link_temp->dpia_bw_alloc_config.estimated_bw; - else if (type == HOST_ROUTER_BW_ALLOCATED) - total_bw += link_temp->dpia_bw_alloc_config.sink_allocated_bw; + hr_index_temp = (dc->links[i]->link_index - lowest_dpia_index) / 2; + + if (hr_index_temp == hr_index) { + link_dpia_primary = dc->links[i]; + link_dpia_secondary = dc->links[i + 1]; + + /** + * If BW allocation enabled on both DPIAs, then + * HR BW = Estimated(dpia_primary) + Allocated(dpia_secondary) + * otherwise HR BW = Estimated(bw alloc enabled dpia) + */ + if ((link_dpia_primary->hpd_status && + link_dpia_primary->dpia_bw_alloc_config.bw_alloc_enabled) && + (link_dpia_secondary->hpd_status && + link_dpia_secondary->dpia_bw_alloc_config.bw_alloc_enabled)) { + total_bw += link_dpia_primary->dpia_bw_alloc_config.estimated_bw + + link_dpia_secondary->dpia_bw_alloc_config.allocated_bw; + } else if (link_dpia_primary->hpd_status && + link_dpia_primary->dpia_bw_alloc_config.bw_alloc_enabled) { + total_bw = link_dpia_primary->dpia_bw_alloc_config.estimated_bw; + } else if (link_dpia_secondary->hpd_status && + link_dpia_secondary->dpia_bw_alloc_config.bw_alloc_enabled) { + total_bw += link_dpia_secondary->dpia_bw_alloc_config.estimated_bw; + } + break; } } return total_bw; } + /* * Cleanup function for when the dpia is unplugged to reset struct * and perform any required clean up @@ -194,42 +240,49 @@ static int get_host_router_total_bw(struct dc_link *link, uint8_t type) * * return: none */ -static bool dpia_bw_alloc_unplug(struct dc_link *link) +static void dpia_bw_alloc_unplug(struct dc_link *link) { - if (!link) - return true; - - return deallocate_usb4_bw(&link->dpia_bw_alloc_config.sink_allocated_bw, - link->dpia_bw_alloc_config.sink_allocated_bw, link); + if (link) { + DC_LOG_DEBUG("%s: resetting bw alloc config for link(%d)\n", + __func__, link->link_index); + reset_bw_alloc_struct(link); + } } + static void set_usb4_req_bw_req(struct dc_link *link, int req_bw) { uint8_t requested_bw; uint32_t temp; - // 1. Add check for this corner case #1 - if (req_bw > link->dpia_bw_alloc_config.estimated_bw) + /* Error check whether request bw greater than allocated */ + if (req_bw > link->dpia_bw_alloc_config.estimated_bw) { + DC_LOG_ERROR("%s: Request bw greater than estimated bw for link(%d)\n", + __func__, link->link_index); req_bw = link->dpia_bw_alloc_config.estimated_bw; + } temp = req_bw * link->dpia_bw_alloc_config.bw_granularity; requested_bw = temp / Kbps_TO_Gbps; - // Always make sure to add more to account for floating points + /* Always make sure to add more to account for floating points */ if (temp % Kbps_TO_Gbps) ++requested_bw; - // 2. Add check for this corner case #2 + /* Error check whether requested and allocated are equal */ req_bw = requested_bw * (Kbps_TO_Gbps / link->dpia_bw_alloc_config.bw_granularity); - if (req_bw == link->dpia_bw_alloc_config.sink_allocated_bw) - return; + if (req_bw == link->dpia_bw_alloc_config.allocated_bw) { + DC_LOG_ERROR("%s: Request bw equals to allocated bw for link(%d)\n", + __func__, link->link_index); + } - if (core_link_write_dpcd( + link->dpia_bw_alloc_config.response_ready = false; // Reset flag + core_link_write_dpcd( link, REQUESTED_BW, &requested_bw, - sizeof(uint8_t)) == DC_OK) - link->dpia_bw_alloc_config.response_ready = false; // Reset flag + sizeof(uint8_t)); } + /* * Return the response_ready flag from dc_link struct * @@ -241,6 +294,7 @@ static bool get_cm_response_ready_flag(struct dc_link *link) { return link->dpia_bw_alloc_config.response_ready; } + // ------------------------------------------------------------------ // PUBLIC FUNCTIONS // ------------------------------------------------------------------ @@ -277,27 +331,27 @@ bool link_dp_dpia_set_dptx_usb4_bw_alloc_support(struct dc_link *link) DPTX_BW_ALLOCATION_MODE_CONTROL, &response, sizeof(uint8_t)) != DC_OK) { - DC_LOG_DEBUG("%s: **** FAILURE Enabling DPtx BW Allocation Mode Support ***\n", - __func__); + DC_LOG_DEBUG("%s: FAILURE Enabling DPtx BW Allocation Mode Support for link(%d)\n", + __func__, link->link_index); } else { // SUCCESS Enabled DPtx BW Allocation Mode Support - link->dpia_bw_alloc_config.bw_alloc_enabled = true; - DC_LOG_DEBUG("%s: **** SUCCESS Enabling DPtx BW Allocation Mode Support ***\n", - __func__); + DC_LOG_DEBUG("%s: SUCCESS Enabling DPtx BW Allocation Mode Support for link(%d)\n", + __func__, link->link_index); ret = true; init_usb4_bw_struct(link); + link->dpia_bw_alloc_config.bw_alloc_enabled = true; } } out: return ret; } + void dpia_handle_bw_alloc_response(struct dc_link *link, uint8_t bw, uint8_t result) { int bw_needed = 0; int estimated = 0; - int host_router_total_estimated_bw = 0; if (!get_bw_alloc_proceed_flag((link))) return; @@ -306,14 +360,22 @@ void dpia_handle_bw_alloc_response(struct dc_link *link, uint8_t bw, uint8_t res case DPIA_BW_REQ_FAILED: - DC_LOG_DEBUG("%s: *** *** BW REQ FAILURE for DP-TX Request *** ***\n", __func__); + /* + * Ideally, we shouldn't run into this case as we always validate available + * bandwidth and request within that limit + */ + estimated = bw * (Kbps_TO_Gbps / link->dpia_bw_alloc_config.bw_granularity); + + DC_LOG_ERROR("%s: BW REQ FAILURE for DP-TX Request for link(%d)\n", + __func__, link->link_index); + DC_LOG_ERROR("%s: current estimated_bw(%d), new estimated_bw(%d)\n", + __func__, link->dpia_bw_alloc_config.estimated_bw, estimated); - // Update the new Estimated BW value updated by CM - link->dpia_bw_alloc_config.estimated_bw = - bw * (Kbps_TO_Gbps / link->dpia_bw_alloc_config.bw_granularity); + /* Update the new Estimated BW value updated by CM */ + link->dpia_bw_alloc_config.estimated_bw = estimated; + /* Allocate the previously requested bandwidth */ set_usb4_req_bw_req(link, link->dpia_bw_alloc_config.estimated_bw); - link->dpia_bw_alloc_config.response_ready = false; /* * If FAIL then it is either: @@ -326,68 +388,34 @@ void dpia_handle_bw_alloc_response(struct dc_link *link, uint8_t bw, uint8_t res case DPIA_BW_REQ_SUCCESS: - DC_LOG_DEBUG("%s: *** BW REQ SUCCESS for DP-TX Request ***\n", __func__); - - // 1. SUCCESS 1st time before any Pruning is done - // 2. SUCCESS after prev. FAIL before any Pruning is done - // 3. SUCCESS after Pruning is done but before enabling link - bw_needed = bw * (Kbps_TO_Gbps / link->dpia_bw_alloc_config.bw_granularity); - // 1. - if (!link->dpia_bw_alloc_config.sink_allocated_bw) { - - allocate_usb4_bw(&link->dpia_bw_alloc_config.sink_allocated_bw, bw_needed, link); - link->dpia_bw_alloc_config.sink_verified_bw = - link->dpia_bw_alloc_config.sink_allocated_bw; - - // SUCCESS from first attempt - if (link->dpia_bw_alloc_config.sink_allocated_bw > - link->dpia_bw_alloc_config.sink_max_bw) - link->dpia_bw_alloc_config.sink_verified_bw = - link->dpia_bw_alloc_config.sink_max_bw; - } - // 3. - else if (link->dpia_bw_alloc_config.sink_allocated_bw) { - - // Find out how much do we need to de-alloc - if (link->dpia_bw_alloc_config.sink_allocated_bw > bw_needed) - deallocate_usb4_bw(&link->dpia_bw_alloc_config.sink_allocated_bw, - link->dpia_bw_alloc_config.sink_allocated_bw - bw_needed, link); - else - allocate_usb4_bw(&link->dpia_bw_alloc_config.sink_allocated_bw, - bw_needed - link->dpia_bw_alloc_config.sink_allocated_bw, link); - } + DC_LOG_DEBUG("%s: BW REQ SUCCESS for DP-TX Request for link(%d)\n", + __func__, link->link_index); + DC_LOG_DEBUG("%s: current allocated_bw(%d), new allocated_bw(%d)\n", + __func__, link->dpia_bw_alloc_config.allocated_bw, bw_needed); - // 4. If this is the 2nd sink then any unused bw will be reallocated to master DPIA - // => check if estimated_bw changed + link->dpia_bw_alloc_config.allocated_bw = bw_needed; link->dpia_bw_alloc_config.response_ready = true; break; case DPIA_EST_BW_CHANGED: - DC_LOG_DEBUG("%s: *** ESTIMATED BW CHANGED for DP-TX Request ***\n", __func__); - estimated = bw * (Kbps_TO_Gbps / link->dpia_bw_alloc_config.bw_granularity); - host_router_total_estimated_bw = get_host_router_total_bw(link, HOST_ROUTER_BW_ESTIMATED); - // 1. If due to unplug of other sink - if (estimated == host_router_total_estimated_bw) { - // First update the estimated & max_bw fields - if (link->dpia_bw_alloc_config.estimated_bw < estimated) - link->dpia_bw_alloc_config.estimated_bw = estimated; - } - // 2. If due to realloc bw btw 2 dpia due to plug OR realloc unused Bw - else { - // We lost estimated bw usually due to plug event of other dpia - link->dpia_bw_alloc_config.estimated_bw = estimated; - } + DC_LOG_DEBUG("%s: ESTIMATED BW CHANGED for link(%d)\n", + __func__, link->link_index); + DC_LOG_DEBUG("%s: current estimated_bw(%d), new estimated_bw(%d)\n", + __func__, link->dpia_bw_alloc_config.estimated_bw, estimated); + + link->dpia_bw_alloc_config.estimated_bw = estimated; break; case DPIA_BW_ALLOC_CAPS_CHANGED: - DC_LOG_DEBUG("%s: *** BW ALLOC CAPABILITY CHANGED for DP-TX Request ***\n", __func__); + DC_LOG_ERROR("%s: BW ALLOC CAPABILITY CHANGED to Disabled for link(%d)\n", + __func__, link->link_index); link->dpia_bw_alloc_config.bw_alloc_enabled = false; break; } @@ -405,21 +433,21 @@ int dpia_handle_usb4_bandwidth_allocation_for_link(struct dc_link *link, int pea if (link->hpd_status && peak_bw > 0) { // If DP over USB4 then we need to check BW allocation - link->dpia_bw_alloc_config.sink_max_bw = peak_bw; - set_usb4_req_bw_req(link, link->dpia_bw_alloc_config.sink_max_bw); + link->dpia_bw_alloc_config.link_max_bw = peak_bw; + set_usb4_req_bw_req(link, link->dpia_bw_alloc_config.link_max_bw); do { - if (!(timeout > 0)) + if (timeout > 0) timeout--; else break; - fsleep(10 * 1000); + msleep(10); } while (!get_cm_response_ready_flag(link)); if (!timeout) ret = 0;// ERROR TIMEOUT waiting for response for allocating bw - else if (link->dpia_bw_alloc_config.sink_allocated_bw > 0) - ret = get_host_router_total_bw(link, HOST_ROUTER_BW_ALLOCATED); + else if (link->dpia_bw_alloc_config.allocated_bw > 0) + ret = link->dpia_bw_alloc_config.allocated_bw; } //2. Cold Unplug else if (!link->hpd_status) @@ -428,65 +456,102 @@ int dpia_handle_usb4_bandwidth_allocation_for_link(struct dc_link *link, int pea out: return ret; } -int link_dp_dpia_allocate_usb4_bandwidth_for_stream(struct dc_link *link, int req_bw) +bool link_dp_dpia_allocate_usb4_bandwidth_for_stream(struct dc_link *link, int req_bw) { - int ret = 0; + bool ret = false; uint8_t timeout = 10; + DC_LOG_DEBUG("%s: ENTER: link(%d), hpd_status(%d), current allocated_bw(%d), req_bw(%d)\n", + __func__, link->link_index, link->hpd_status, + link->dpia_bw_alloc_config.allocated_bw, req_bw); + if (!get_bw_alloc_proceed_flag(link)) goto out; - /* - * Sometimes stream uses same timing parameters as the already - * allocated max sink bw so no need to re-alloc - */ - if (req_bw != link->dpia_bw_alloc_config.sink_allocated_bw) { - set_usb4_req_bw_req(link, req_bw); - do { - if (!(timeout > 0)) - timeout--; - else - break; - udelay(10 * 1000); - } while (!get_cm_response_ready_flag(link)); + set_usb4_req_bw_req(link, req_bw); + do { + if (timeout > 0) + timeout--; + else + break; + msleep(10); + } while (!get_cm_response_ready_flag(link)); - if (!timeout) - ret = 0;// ERROR TIMEOUT waiting for response for allocating bw - else if (link->dpia_bw_alloc_config.sink_allocated_bw > 0) - ret = get_host_router_total_bw(link, HOST_ROUTER_BW_ALLOCATED); - } + if (timeout) + ret = true; out: + DC_LOG_DEBUG("%s: EXIT: timeout(%d), ret(%d)\n", __func__, timeout, ret); return ret; } + bool dpia_validate_usb4_bw(struct dc_link **link, int *bw_needed_per_dpia, const unsigned int num_dpias) { bool ret = true; - int bw_needed_per_hr[MAX_HR_NUM] = { 0, 0 }; - uint8_t lowest_dpia_index = 0, dpia_index = 0; - uint8_t i; + int bw_needed_per_hr[MAX_HR_NUM] = { 0, 0 }, host_router_total_dp_bw = 0; + uint8_t lowest_dpia_index, i, hr_index; if (!num_dpias || num_dpias > MAX_DPIA_NUM) return ret; - //Get total Host Router BW & Validate against each Host Router max BW + lowest_dpia_index = get_lowest_dpia_index(link[0]); + + /* get total Host Router BW with granularity for the given modes */ for (i = 0; i < num_dpias; ++i) { + int granularity_Gbps = 0; + int bw_granularity = 0; if (!link[i]->dpia_bw_alloc_config.bw_alloc_enabled) continue; - lowest_dpia_index = get_lowest_dpia_index(link[i]); if (link[i]->link_index < lowest_dpia_index) continue; - dpia_index = (link[i]->link_index - lowest_dpia_index) / 2; - bw_needed_per_hr[dpia_index] += bw_needed_per_dpia[i]; - if (bw_needed_per_hr[dpia_index] > get_host_router_total_bw(link[i], HOST_ROUTER_BW_ALLOCATED)) { + granularity_Gbps = (Kbps_TO_Gbps / link[i]->dpia_bw_alloc_config.bw_granularity); + bw_granularity = (bw_needed_per_dpia[i] / granularity_Gbps) * granularity_Gbps + + ((bw_needed_per_dpia[i] % granularity_Gbps) ? granularity_Gbps : 0); - ret = false; - break; + hr_index = (link[i]->link_index - lowest_dpia_index) / 2; + bw_needed_per_hr[hr_index] += bw_granularity; + } + + /* validate against each Host Router max BW */ + for (hr_index = 0; hr_index < MAX_HR_NUM; ++hr_index) { + if (bw_needed_per_hr[hr_index]) { + host_router_total_dp_bw = get_host_router_total_dp_tunnel_bw(link[0]->dc, hr_index); + if (bw_needed_per_hr[hr_index] > host_router_total_dp_bw) { + ret = false; + break; + } } } return ret; } + +int link_dp_dpia_get_dp_overhead_in_dp_tunneling(struct dc_link *link) +{ + int dp_overhead = 0, link_mst_overhead = 0; + + if (!get_bw_alloc_proceed_flag((link))) + return dp_overhead; + + /* if its mst link, add MTPH overhead */ + if ((link->type == dc_connection_mst_branch) && + !link->dpcd_caps.channel_coding_cap.bits.DP_128b_132b_SUPPORTED) { + /* For 8b/10b encoding: MTP is 64 time slots long, slot 0 is used for MTPH + * MST overhead is 1/64 of link bandwidth (excluding any overhead) + */ + const struct dc_link_settings *link_cap = + dc_link_get_link_cap(link); + uint32_t link_bw_in_kbps = (uint32_t)link_cap->link_rate * + (uint32_t)link_cap->lane_count * + LINK_RATE_REF_FREQ_IN_KHZ * 8; + link_mst_overhead = (link_bw_in_kbps / 64) + ((link_bw_in_kbps % 64) ? 1 : 0); + } + + /* add all the overheads */ + dp_overhead = link_mst_overhead; + + return dp_overhead; +} |