drm/nouveau/disp: move DP link config into acquire

Aside from fixing MST->SST switching (KMS never turned off MST link config),
this should preserve existing behaviour for the moment, but provide a path
for the KMS driver to have more explicit control of the DP link, which has
been requested by Lyude.

More research into modeset/supervisor interactions is needed before we can
have fully explicit control from the KMS driver.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>

Author: Ben Skeggs

drivers/gpu/drm/nouveau/dispnv50/disp.c

@@ -1014,7 +1014,7 @@ nv50_msto_atomic_enable(struct drm_encoder *encoder, struct drm_atomic_state *st
 
 	if (!mstm->links++) {
 		/*XXX: MST audio. */
-		nvif_outp_acquire_dp(&mstm->outp->outp, false);
+		nvif_outp_acquire_dp(&mstm->outp->outp, mstm->outp->dp.dpcd, 0, 0, false, true);
 	}
 
 	if (mstm->outp->outp.or.link & 1)
@@ -1380,26 +1380,6 @@ nv50_mstm_remove(struct nv50_mstm *mstm)
 	drm_dp_mst_topology_mgr_set_mst(&mstm->mgr, false);
 }
 
-static int
-nv50_mstm_enable(struct nv50_mstm *mstm, int state)
-{
-	struct nouveau_encoder *outp = mstm->outp;
-	struct {
-		struct nv50_disp_mthd_v1 base;
-		struct nv50_disp_sor_dp_mst_link_v0 mst;
-	} args = {
-		.base.version = 1,
-		.base.method = NV50_DISP_MTHD_V1_SOR_DP_MST_LINK,
-		.base.hasht = outp->dcb->hasht,
-		.base.hashm = outp->dcb->hashm,
-		.mst.state = state,
-	};
-	struct nouveau_drm *drm = nouveau_drm(outp->base.base.dev);
-	struct nvif_object *disp = &drm->display->disp.object;
-
-	return nvif_mthd(disp, 0, &args, sizeof(args));
-}
-
 int
 nv50_mstm_detect(struct nouveau_encoder *outp)
 {
@@ -1420,15 +1400,9 @@ nv50_mstm_detect(struct nouveau_encoder *outp)
 		return ret;
 
 	/* And start enabling */
-	ret = nv50_mstm_enable(mstm, true);
-	if (ret)
-		return ret;
-
 	ret = drm_dp_mst_topology_mgr_set_mst(&mstm->mgr, true);
-	if (ret) {
-		nv50_mstm_enable(mstm, false);
+	if (ret)
 		return ret;
-	}
 
 	mstm->is_mst = true;
 	return 1;
@@ -1660,7 +1634,7 @@ nv50_sor_atomic_enable(struct drm_encoder *encoder, struct drm_atomic_state *sta
 		nvif_outp_acquire_lvds(&nv_encoder->outp, lvds_dual, lvds_8bpc);
 		break;
 	case DCB_OUTPUT_DP:
-		nvif_outp_acquire_dp(&nv_encoder->outp, hda);
+		nvif_outp_acquire_dp(&nv_encoder->outp, nv_encoder->dp.dpcd, 0, 0, hda, false);
 		depth = nv50_dp_bpc_to_depth(asyh->or.bpc);
 
 		if (nv_encoder->outp.or.link & 1)
@@ -1858,7 +1832,7 @@ nv50_pior_atomic_enable(struct drm_encoder *encoder, struct drm_atomic_state *st
 		break;
 	case DCB_OUTPUT_DP:
 		ctrl |= NVDEF(NV507D, PIOR_SET_CONTROL, PROTOCOL, EXT_TMDS_ENC);
-		nvif_outp_acquire_dp(&nv_encoder->outp, false);
+		nvif_outp_acquire_dp(&nv_encoder->outp, nv_encoder->dp.dpcd, 0, 0, false, false);
 		break;
 	default:
 		BUG();

drivers/gpu/drm/nouveau/include/nvif/cl5070.h

@@ -28,20 +28,13 @@ struct nv50_disp_scanoutpos_v0 {
 
 struct nv50_disp_mthd_v1 {
 	__u8  version;
-#define NV50_DISP_MTHD_V1_SOR_DP_MST_LINK                                  0x25
 #define NV50_DISP_MTHD_V1_SOR_DP_MST_VCPI                                  0x26
 	__u8  method;
 	__u16 hasht;
 	__u16 hashm;
 	__u8  pad06[2];
 };
 
-struct nv50_disp_sor_dp_mst_link_v0 {
-	__u8  version;
-	__u8  state;
-	__u8  pad02[6];
-};
-
 struct nv50_disp_sor_dp_mst_vcpi_v0 {
 	__u8  version;
 	__u8  pad01[1];

drivers/gpu/drm/nouveau/include/nvif/if0012.h

@@ -55,8 +55,12 @@ union nvif_outp_acquire_args {
 				__u8 pad02[6];
 			} lvds;
 			struct {
+				__u8 link_nr; /* 0 = highest possible. */
+				__u8 link_bw; /* 0 = highest possible, DP BW code otherwise. */
 				__u8 hda;
-				__u8 pad01[7];
+				__u8 mst;
+				__u8 pad04[4];
+				__u8 dpcd[16];
 			} dp;
 		};
 	} v0;

drivers/gpu/drm/nouveau/include/nvif/outp.h

@@ -21,7 +21,8 @@ int nvif_outp_acquire_rgb_crt(struct nvif_outp *);
 int nvif_outp_acquire_tmds(struct nvif_outp *, int head,
 			   bool hdmi, u8 max_ac_packet, u8 rekey, u8 scdc, bool hda);
 int nvif_outp_acquire_lvds(struct nvif_outp *, bool dual, bool bpc8);
-int nvif_outp_acquire_dp(struct nvif_outp *, bool hda);
+int nvif_outp_acquire_dp(struct nvif_outp *, u8 dpcd[16],
+			 int link_nr, int link_bw, bool hda, bool mst);
 void nvif_outp_release(struct nvif_outp *);
 int nvif_outp_infoframe(struct nvif_outp *, u8 type, struct nvif_outp_infoframe_v0 *, u32 size);
 int nvif_outp_hda_eld(struct nvif_outp *, int head, void *data, u32 size);

drivers/gpu/drm/nouveau/nvif/outp.c

@@ -84,16 +84,22 @@ nvif_outp_acquire(struct nvif_outp *outp, u8 proto, struct nvif_outp_acquire_v0
 }
 
 int
-nvif_outp_acquire_dp(struct nvif_outp *outp,  bool hda)
+nvif_outp_acquire_dp(struct nvif_outp *outp, u8 dpcd[16],
+		     int link_nr, int link_bw, bool hda, bool mst)
 {
 	struct nvif_outp_acquire_v0 args;
 	int ret;
 
+	args.dp.link_nr = link_nr;
+	args.dp.link_bw = link_bw;
 	args.dp.hda = hda;
+	args.dp.mst = mst;
+	memcpy(args.dp.dpcd, dpcd, sizeof(args.dp.dpcd));
 
 	ret = nvif_outp_acquire(outp, NVIF_OUTP_ACQUIRE_V0_DP, &args);
 	NVIF_ERRON(ret, &outp->object,
-		   "[ACQUIRE proto:DP hda:%d] or:%d link:%d", args.dp.hda, args.or, args.link);
+		   "[ACQUIRE proto:DP link_nr:%d link_bw:%02x hda:%d mst:%d] or:%d link:%d",
+		   args.dp.link_nr, args.dp.link_bw, args.dp.hda, args.dp.mst, args.or, args.link);
 	return ret;
 }
 

drivers/gpu/drm/nouveau/nvkm/engine/disp/dp.c

@@ -287,7 +287,7 @@ nvkm_dp_train_links(struct nvkm_outp *outp, int rate)
 	u8 sink[2], data;
 	int ret;
 
-	OUTP_DBG(outp, "training %d x %d MB/s", ior->dp.nr, ior->dp.bw * 27);
+	OUTP_DBG(outp, "training %dx%02x", ior->dp.nr, ior->dp.bw);
 
 	/* Intersect misc. capabilities of the OR and sink. */
 	if (disp->engine.subdev.device->chipset < 0x110)
@@ -455,6 +455,21 @@ nvkm_dp_train(struct nvkm_outp *outp, u32 dataKBps)
 	/* Link training. */
 	OUTP_DBG(outp, "training");
 	nvkm_dp_train_init(outp);
+
+	/* Validate and train at configuration requested (if any) on ACQUIRE. */
+	if (outp->dp.lt.nr) {
+		for (nr = outp->dp.links; ret < 0 && nr; nr >>= 1) {
+			for (rate = 0; nr == outp->dp.lt.nr && rate < outp->dp.rates; rate++) {
+				if (outp->dp.rate[rate].rate / 27000 == outp->dp.lt.bw) {
+					ior->dp.bw = outp->dp.rate[rate].rate / 27000;
+					ior->dp.nr = nr;
+					ret = nvkm_dp_train_links(outp, rate);
+				}
+			}
+		}
+	}
+
+	/* Otherwise, loop through all valid link configurations that support the data rate. */
 	for (nr = outp->dp.links; ret < 0 && nr; nr >>= 1) {
 		for (rate = 0; ret < 0 && rate < outp->dp.rates; rate++) {
 			if (outp->dp.rate[rate].rate * nr >= dataKBps || WARN_ON(!ior->dp.nr)) {
@@ -465,6 +480,8 @@ nvkm_dp_train(struct nvkm_outp *outp, u32 dataKBps)
 			}
 		}
 	}
+
+	/* Finish up. */
 	nvkm_dp_train_fini(outp);
 	if (ret < 0)
 		OUTP_ERR(outp, "training failed");

drivers/gpu/drm/nouveau/nvkm/engine/disp/outp.h

@@ -54,6 +54,8 @@ struct nvkm_outp {
 			struct mutex mutex;
 			struct {
 				atomic_t done;
+				u8 nr;
+				u8 bw;
 				bool mst;
 			} lt;
 		} dp;

drivers/gpu/drm/nouveau/nvkm/engine/disp/rootnv50.c

@@ -91,21 +91,6 @@ nv50_disp_root_mthd_(struct nvkm_object *object, u32 mthd, void *data, u32 size)
 	}
 
 	switch (mthd * !!outp) {
-	case NV50_DISP_MTHD_V1_SOR_DP_MST_LINK: {
-		union {
-			struct nv50_disp_sor_dp_mst_link_v0 v0;
-		} *args = data;
-		int ret = -ENOSYS;
-		nvif_ioctl(object, "disp sor dp mst link size %d\n", size);
-		if (!(ret = nvif_unpack(ret, &data, &size, args->v0, 0, 0, false))) {
-			nvif_ioctl(object, "disp sor dp mst link vers %d state %d\n",
-				   args->v0.version, args->v0.state);
-			outp->dp.lt.mst = !!args->v0.state;
-			return 0;
-		} else
-			return ret;
-	}
-		break;
 	case NV50_DISP_MTHD_V1_SOR_DP_MST_VCPI: {
 		union {
 			struct nv50_disp_sor_dp_mst_vcpi_v0 v0;

drivers/gpu/drm/nouveau/nvkm/engine/disp/uoutp.c

@@ -100,6 +100,23 @@ nvkm_uoutp_mthd_release(struct nvkm_outp *outp, void *argv, u32 argc)
 	return 0;
 }
 
+static int
+nvkm_uoutp_mthd_acquire_dp(struct nvkm_outp *outp, u8 dpcd[16],
+			   u8 link_nr, u8 link_bw, bool hda, bool mst)
+{
+	int ret;
+
+	ret = nvkm_outp_acquire(outp, NVKM_OUTP_USER, hda);
+	if (ret)
+		return ret;
+
+	memcpy(outp->dp.dpcd, dpcd, sizeof(outp->dp.dpcd));
+	outp->dp.lt.nr = link_nr;
+	outp->dp.lt.bw = link_bw;
+	outp->dp.lt.mst = mst;
+	return 0;
+}
+
 static int
 nvkm_uoutp_mthd_acquire_tmds(struct nvkm_outp *outp, u8 head, u8 hdmi, u8 hdmi_max_ac_packet,
 			     u8 hdmi_rekey, u8 hdmi_scdc, u8 hdmi_hda)
@@ -152,6 +169,8 @@ nvkm_uoutp_mthd_acquire(struct nvkm_outp *outp, void *argv, u32 argc)
 
 	if (argc != sizeof(args->v0) || args->v0.version != 0)
 		return -ENOSYS;
+	if (outp->ior)
+		return -EBUSY;
 
 	switch (args->v0.proto) {
 	case NVIF_OUTP_ACQUIRE_V0_RGB_CRT:
@@ -165,12 +184,16 @@ nvkm_uoutp_mthd_acquire(struct nvkm_outp *outp, void *argv, u32 argc)
 							 args->v0.tmds.hdmi_scdc,
 							 args->v0.tmds.hdmi_hda);
 		break;
-	case NVIF_OUTP_ACQUIRE_V0_DP:
-		ret = nvkm_outp_acquire(outp, NVKM_OUTP_USER, args->v0.dp.hda);
-		break;
 	case NVIF_OUTP_ACQUIRE_V0_LVDS:
 		ret = nvkm_uoutp_mthd_acquire_lvds(outp, args->v0.lvds.dual, args->v0.lvds.bpc8);
 		break;
+	case NVIF_OUTP_ACQUIRE_V0_DP:
+		ret = nvkm_uoutp_mthd_acquire_dp(outp, args->v0.dp.dpcd,
+						       args->v0.dp.link_nr,
+						       args->v0.dp.link_bw,
+						       args->v0.dp.hda != 0,
+						       args->v0.dp.mst != 0);
+		break;
 	default:
 		ret = -EINVAL;
 		break;