drm/amd/display: handle invalid connector indices

[Why]
The function to count the number of valid connectors does not
guarantee that the first n indices are valid, only that there
exist n valid indices. When invalid indices are present, this
results in later valid connectors being missed, as processing
would end after checking n indices.

[How]
 - count valid indices separately from total indices examined
 - add explicit definition of MAX_LINKS
Reviewed-by: Dillon Varone <dillon.varone@amd.com>
Acked-by: Roman Li <roman.li@amd.com>
Signed-off-by: Joshua Aberback <joshua.aberback@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c

@@ -503,7 +503,7 @@ static void dcn2_notify_link_rate_change(struct clk_mgr *clk_mgr_base, struct dc
 
 	clk_mgr->cur_phyclk_req_table[link->link_index] = link->cur_link_settings.link_rate * LINK_RATE_REF_FREQ_IN_KHZ;
 
-	for (i = 0; i < MAX_PIPES * 2; i++) {
+	for (i = 0; i < MAX_LINKS; i++) {
 		if (clk_mgr->cur_phyclk_req_table[i] > max_phyclk_req)
 			max_phyclk_req = clk_mgr->cur_phyclk_req_table[i];
 	}

drivers/gpu/drm/amd/display/dc/clk_mgr/dcn21/rn_clk_mgr.c

@@ -548,7 +548,7 @@ static void rn_notify_link_rate_change(struct clk_mgr *clk_mgr_base, struct dc_l
 
 	clk_mgr->cur_phyclk_req_table[link->link_index] = link->cur_link_settings.link_rate * LINK_RATE_REF_FREQ_IN_KHZ;
 
-	for (i = 0; i < MAX_PIPES * 2; i++) {
+	for (i = 0; i < MAX_LINKS; i++) {
 		if (clk_mgr->cur_phyclk_req_table[i] > max_phyclk_req)
 			max_phyclk_req = clk_mgr->cur_phyclk_req_table[i];
 	}

drivers/gpu/drm/amd/display/dc/clk_mgr/dcn30/dcn30_clk_mgr.c

@@ -474,7 +474,7 @@ static void dcn30_notify_link_rate_change(struct clk_mgr *clk_mgr_base, struct d
 
 	clk_mgr->cur_phyclk_req_table[link->link_index] = link->cur_link_settings.link_rate * LINK_RATE_REF_FREQ_IN_KHZ;
 
-	for (i = 0; i < MAX_PIPES * 2; i++) {
+	for (i = 0; i < MAX_LINKS; i++) {
 		if (clk_mgr->cur_phyclk_req_table[i] > max_phyclk_req)
 			max_phyclk_req = clk_mgr->cur_phyclk_req_table[i];
 	}

drivers/gpu/drm/amd/display/dc/core/dc.c

@@ -212,7 +212,8 @@ static bool create_links(
 		connectors_num,
 		num_virtual_links);
 
-	for (i = 0; i < connectors_num; i++) {
+	// condition loop on link_count to allow skipping invalid indices
+	for (i = 0; dc->link_count < connectors_num && i < MAX_LINKS; i++) {
 		struct link_init_data link_init_params = {0};
 		struct dc_link *link;
 

drivers/gpu/drm/amd/display/dc/dc.h

@@ -1327,7 +1327,7 @@ struct dc {
 	struct dc_phy_addr_space_config vm_pa_config;
 
 	uint8_t link_count;
-	struct dc_link *links[MAX_PIPES * 2];
+	struct dc_link *links[MAX_LINKS];
 	struct link_service *link_srv;
 
 	struct dc_state *current_state;

drivers/gpu/drm/amd/display/dc/inc/hw/clk_mgr_internal.h

@@ -349,7 +349,7 @@ struct clk_mgr_internal {
 	enum dm_pp_clocks_state cur_min_clks_state;
 	bool periodic_retraining_disabled;
 
-	unsigned int cur_phyclk_req_table[MAX_PIPES * 2];
+	unsigned int cur_phyclk_req_table[MAX_LINKS];
 
 	bool smu_present;
 	void *wm_range_table;

drivers/gpu/drm/amd/display/dc/inc/hw/hw_shared.h

@@ -44,6 +44,7 @@
  */
 #define MAX_PIPES 6
 #define MAX_PHANTOM_PIPES (MAX_PIPES / 2)
+#define MAX_LINKS (MAX_PIPES * 2)
 #define MAX_DIG_LINK_ENCODERS 7
 #define MAX_DWB_PIPES	1
 #define MAX_HPO_DP2_ENCODERS	4

drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c

@@ -166,7 +166,7 @@ static uint8_t get_lowest_dpia_index(struct dc_link *link)
 	uint8_t idx = 0xFF;
 	int i;
 
-	for (i = 0; i < MAX_PIPES * 2; ++i) {
+	for (i = 0; i < MAX_LINKS; ++i) {
 
 		if (!dc_struct->links[i] ||
 				dc_struct->links[i]->ep_type != DISPLAY_ENDPOINT_USB4_DPIA)
@@ -196,7 +196,7 @@ static int get_host_router_total_dp_tunnel_bw(const struct dc *dc, uint8_t hr_in
 	struct dc_link *link_dpia_primary, *link_dpia_secondary;
 	int total_bw = 0;
 
-	for (uint8_t i = 0; i < (MAX_PIPES * 2) - 1; ++i) {
+	for (uint8_t i = 0; i < MAX_LINKS - 1; ++i) {
 
 		if (!dc->links[i] || dc->links[i]->ep_type != DISPLAY_ENDPOINT_USB4_DPIA)
 			continue;