drm/amd/display: Allocate zero bw after bw alloc enable

From Meenakshikumar Somasundaram
53a7d15331b084378ca7255695d2987a3fdf7ad6 in linux-6.6.y/6.6.33
46fe9cb1a9e62f4e6229f48ae303ef8e6c1fdc64 in mainline linux

diff --git a/sys/dev/pci/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c b/sys/dev/pci/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c
index 3db9489..4c6a6d6 100644 (file)
--- a/sys/dev/pci/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c
+++ b/sys/dev/pci/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c
@@ -270,7 +270,7 @@ static void set_usb4_req_bw_req(struct dc_link *link, int req_bw)
 
        /* 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.allocated_bw) {
+       if (req_bw && (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);
        }
@@ -341,6 +341,14 @@ bool link_dp_dpia_set_dptx_usb4_bw_alloc_support(struct dc_link *link)
                        ret = true;
                        init_usb4_bw_struct(link);
                        link->dpia_bw_alloc_config.bw_alloc_enabled = true;
+
+                       /*
+                        * During DP tunnel creation, CM preallocates BW and reduces estimated BW of other
+                        * DPIA. CM release preallocation only when allocation is complete. Do zero alloc
+                        * to make the CM to release preallocation and update estimated BW correctly for
+                        * all DPIAs per host router
+                        */
+                       link_dp_dpia_allocate_usb4_bandwidth_for_stream(link, 0);
                }
        }