drm/nouveau/disp: limit dp capabilities as per dcb

[karo-tx-linux.git] / drivers / gpu / drm / nouveau / core / engine / disp / dport.c

diff --git a/drivers/gpu/drm/nouveau/core/engine/disp/dport.c b/drivers/gpu/drm/nouveau/core/engine/disp/dport.c
index 1bd4c63369c16f96fd30762c1faaddb60acdf337..2aedb4e47d0335f9c7b5ffab1876848e5aeb499b 100644 (file)
--- a/drivers/gpu/drm/nouveau/core/engine/disp/dport.c
+++ b/drivers/gpu/drm/nouveau/core/engine/disp/dport.c
@@ -312,6 +312,14 @@ nouveau_dp_train(struct nouveau_disp *disp, const struct nouveau_dp_func *func,
                ERR("failed to read DPCD\n");
        }
 
+       /* bring capabilities within encoder limits */
+       if ((dp->dpcd[2] & 0x1f) > dp->outp->dpconf.link_nr) {
+               dp->dpcd[2] &= ~0x1f;
+               dp->dpcd[2] |= dp->outp->dpconf.link_nr;
+       }
+       if (dp->dpcd[1] > dp->outp->dpconf.link_bw)
+               dp->dpcd[1] = dp->outp->dpconf.link_bw;
+
        /* adjust required bandwidth for 8B/10B coding overhead */
        datarate = (datarate / 8) * 10;