2 files changed, 16 insertions, 0 deletions

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dport.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dport.c
index 74e2f7c6c07e..9688970eca47 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dport.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dport.c
@@ -328,6 +328,7 @@ nvkm_dp_train(struct work_struct *w)
                 .outp = outp,
         }, *dp = &_dp;
         u32 datarate = 0;
+        u8  pwr;
         int ret;
 
         if (!outp->base.info.location && disp->func->sor.magic)
@@ -355,6 +356,15 @@ nvkm_dp_train(struct work_struct *w)
         /* disable link interrupt handling during link training */
         nvkm_notify_put(&outp->irq);
 
+        /* ensure sink is not in a low-power state */
+        if (!nvkm_rdaux(outp->aux, DPCD_SC00, &pwr, 1)) {
+                if ((pwr & DPCD_SC00_SET_POWER) != DPCD_SC00_SET_POWER_D0) {
+                        pwr &= ~DPCD_SC00_SET_POWER;
+                        pwr |=  DPCD_SC00_SET_POWER_D0;
+                        nvkm_wraux(outp->aux, DPCD_SC00, &pwr, 1);
+                }
+        }
+
         /* enable down-spreading and execute pre-train script from vbios */
         dp_link_train_init(dp, outp->dpcd[3] & 0x01);
 
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dport.h b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dport.h
index 9596290329c7..6e10c5e0ef11 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/dport.h
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/dport.h
@@ -71,5 +71,11 @@
 #define DPCD_LS0C_LANE1_POST_CURSOR2                                       0x0c
 #define DPCD_LS0C_LANE0_POST_CURSOR2                                       0x03
 
+/* DPCD Sink Control */
+#define DPCD_SC00                                                       0x00600
+#define DPCD_SC00_SET_POWER                                                0x03
+#define DPCD_SC00_SET_POWER_D0                                             0x01
+#define DPCD_SC00_SET_POWER_D3                                             0x03
+
 void nvkm_dp_train(struct work_struct *);
 #endif