Commit f479c0ba authored by Ben Skeggs's avatar Ben Skeggs
Browse files

drm/nouveau/kms/nv50: initial support for DP 1.2 multi-stream 



Signed-off-by: default avatarBen Skeggs <bskeggs@redhat.com>
parent d665c7e9

drivers/gpu/drm/nouveau/nouveau_connector.c

+9 −0
Original line number Diff line number Diff line
@@ -1118,12 +1118,21 @@ nouveau_connector_hotplug(struct nvif_notify *notify) 
	struct nouveau_drm *drm = nouveau_drm(connector->dev);

	const struct nvif_notify_conn_rep_v0 *rep = notify->data;

	const char *name = connector->name;

	struct nouveau_encoder *nv_encoder;



	if (rep->mask & NVIF_NOTIFY_CONN_V0_IRQ) {

		NV_DEBUG(drm, "service %s\n", name);

		if ((nv_encoder = find_encoder(connector, DCB_OUTPUT_DP)))

			nv50_mstm_service(nv_encoder->dp.mstm);

	} else {

		bool plugged = (rep->mask != NVIF_NOTIFY_CONN_V0_UNPLUG);



		NV_DEBUG(drm, "%splugged %s\n", plugged ? "" : "un", name);

		if ((nv_encoder = find_encoder(connector, DCB_OUTPUT_DP))) {

			if (!plugged)

				nv50_mstm_remove(nv_encoder->dp.mstm);

		}



		drm_helper_hpd_irq_event(connector->dev);

	}

drivers/gpu/drm/nouveau/nouveau_dp.c

+7 −1
Original line number Diff line number Diff line
@@ -33,6 +33,10 @@ 
#include <nvif/class.h>

#include <nvif/cl5070.h>



MODULE_PARM_DESC(mst, "Enable DisplayPort multi-stream (default: enabled)");

static int nouveau_mst = 1;

module_param_named(mst, nouveau_mst, int, 0400);



static void

nouveau_dp_probe_oui(struct drm_device *dev, struct nvkm_i2c_aux *aux, u8 *dpcd)

{
@@ -88,7 +92,9 @@ nouveau_dp_detect(struct nouveau_encoder *nv_encoder) 


	nouveau_dp_probe_oui(dev, aux, dpcd);



	ret = nv50_mstm_detect(nv_encoder->dp.mstm, dpcd, 0);

	ret = nv50_mstm_detect(nv_encoder->dp.mstm, dpcd, nouveau_mst);

	if (ret == 1)

		return NOUVEAU_DP_MST;

	if (ret == 0)

		return NOUVEAU_DP_SST;

	return ret;

drivers/gpu/drm/nouveau/nouveau_encoder.h

+2 −0
Original line number Diff line number Diff line
@@ -103,4 +103,6 @@ struct nouveau_connector * 
nouveau_encoder_connector_get(struct nouveau_encoder *encoder);



int nv50_mstm_detect(struct nv50_mstm *, u8 dpcd[8], int allow);

void nv50_mstm_remove(struct nv50_mstm *);

void nv50_mstm_service(struct nv50_mstm *);

#endif /* __NOUVEAU_ENCODER_H__ */

drivers/gpu/drm/nouveau/nv50_display.c

+553 −1
Original line number Diff line number Diff line
@@ -2804,12 +2804,502 @@ nv50_hdmi_enable(struct drm_encoder *encoder, struct drm_display_mode *mode) 
/******************************************************************************

 * MST

 *****************************************************************************/

#define nv50_mstm(p) container_of((p), struct nv50_mstm, mgr)

#define nv50_mstc(p) container_of((p), struct nv50_mstc, connector)

#define nv50_msto(p) container_of((p), struct nv50_msto, encoder)



struct nv50_mstm {

	struct nouveau_encoder *outp;



	struct drm_dp_mst_topology_mgr mgr;

	struct nv50_msto *msto[4];



	bool modified;

};



struct nv50_mstc {

	struct nv50_mstm *mstm;

	struct drm_dp_mst_port *port;

	struct drm_connector connector;



	struct drm_display_mode *native;

	struct edid *edid;



	int pbn;

};



struct nv50_msto {

	struct drm_encoder encoder;



	struct nv50_head *head;

	struct nv50_mstc *mstc;

	bool disabled;

};



static struct drm_dp_payload *

nv50_msto_payload(struct nv50_msto *msto)

{

	struct nouveau_drm *drm = nouveau_drm(msto->encoder.dev);

	struct nv50_mstc *mstc = msto->mstc;

	struct nv50_mstm *mstm = mstc->mstm;

	int vcpi = mstc->port->vcpi.vcpi, i;



	NV_ATOMIC(drm, "%s: vcpi %d\n", msto->encoder.name, vcpi);

	for (i = 0; i < mstm->mgr.max_payloads; i++) {

		struct drm_dp_payload *payload = &mstm->mgr.payloads[i];

		NV_ATOMIC(drm, "%s: %d: vcpi %d start 0x%02x slots 0x%02x\n",

			  mstm->outp->base.base.name, i, payload->vcpi,

			  payload->start_slot, payload->num_slots);

	}



	for (i = 0; i < mstm->mgr.max_payloads; i++) {

		struct drm_dp_payload *payload = &mstm->mgr.payloads[i];

		if (payload->vcpi == vcpi)

			return payload;

	}



	return NULL;

}



static void

nv50_msto_cleanup(struct nv50_msto *msto)

{

	struct nouveau_drm *drm = nouveau_drm(msto->encoder.dev);

	struct nv50_mstc *mstc = msto->mstc;

	struct nv50_mstm *mstm = mstc->mstm;



	NV_ATOMIC(drm, "%s: msto cleanup\n", msto->encoder.name);

	if (mstc->port && mstc->port->vcpi.vcpi > 0 && !nv50_msto_payload(msto))

		drm_dp_mst_deallocate_vcpi(&mstm->mgr, mstc->port);

	if (msto->disabled) {

		msto->mstc = NULL;

		msto->head = NULL;

		msto->disabled = false;

	}

}



static void

nv50_msto_prepare(struct nv50_msto *msto)

{

	struct nouveau_drm *drm = nouveau_drm(msto->encoder.dev);

	struct nv50_mstc *mstc = msto->mstc;

	struct nv50_mstm *mstm = mstc->mstm;

	struct {

		struct nv50_disp_mthd_v1 base;

		struct nv50_disp_sor_dp_mst_vcpi_v0 vcpi;

	} args = {

		.base.version = 1,

		.base.method = NV50_DISP_MTHD_V1_SOR_DP_MST_VCPI,

		.base.hasht  = mstm->outp->dcb->hasht,

		.base.hashm  = (0xf0ff & mstm->outp->dcb->hashm) |

			       (0x0100 << msto->head->base.index),

	};



	NV_ATOMIC(drm, "%s: msto prepare\n", msto->encoder.name);

	if (mstc->port && mstc->port->vcpi.vcpi > 0) {

		struct drm_dp_payload *payload = nv50_msto_payload(msto);

		if (payload) {

			args.vcpi.start_slot = payload->start_slot;

			args.vcpi.num_slots = payload->num_slots;

			args.vcpi.pbn = mstc->port->vcpi.pbn;

			args.vcpi.aligned_pbn = mstc->port->vcpi.aligned_pbn;

		}

	}



	NV_ATOMIC(drm, "%s: %s: %02x %02x %04x %04x\n",

		  msto->encoder.name, msto->head->base.base.name,

		  args.vcpi.start_slot, args.vcpi.num_slots,

		  args.vcpi.pbn, args.vcpi.aligned_pbn);

	nvif_mthd(&drm->display->disp, 0, &args, sizeof(args));

}



static int

nv50_msto_atomic_check(struct drm_encoder *encoder,

		       struct drm_crtc_state *crtc_state,

		       struct drm_connector_state *conn_state)

{

	struct nv50_mstc *mstc = nv50_mstc(conn_state->connector);

	struct nv50_mstm *mstm = mstc->mstm;

	int bpp = conn_state->connector->display_info.bpc * 3;

	int slots;



	mstc->pbn = drm_dp_calc_pbn_mode(crtc_state->adjusted_mode.clock, bpp);



	slots = drm_dp_find_vcpi_slots(&mstm->mgr, mstc->pbn);

	if (slots < 0)

		return slots;



	return nv50_outp_atomic_check_view(encoder, crtc_state, conn_state,

					   mstc->native);

}



static void

nv50_msto_enable(struct drm_encoder *encoder)

{

	struct nv50_head *head = nv50_head(encoder->crtc);

	struct nv50_msto *msto = nv50_msto(encoder);

	struct nv50_mstc *mstc = NULL;

	struct nv50_mstm *mstm = NULL;

	struct drm_connector *connector;

	u8 proto, depth;

	int slots;

	bool r;



	drm_for_each_connector(connector, encoder->dev) {

		if (connector->state->best_encoder == &msto->encoder) {

			mstc = nv50_mstc(connector);

			mstm = mstc->mstm;

			break;

		}

	}



	if (WARN_ON(!mstc))

		return;



	r = drm_dp_mst_allocate_vcpi(&mstm->mgr, mstc->port, mstc->pbn, &slots);

	WARN_ON(!r);



	if (mstm->outp->dcb->sorconf.link & 1)

		proto = 0x8;

	else

		proto = 0x9;



	switch (mstc->connector.display_info.bpc) {

	case  6: depth = 0x2; break;

	case  8: depth = 0x5; break;

	case 10:

	default: depth = 0x6; break;

	}



	mstm->outp->update(mstm->outp, head->base.index,

			   &head->base.base.state->adjusted_mode, proto, depth);



	msto->head = head;

	msto->mstc = mstc;

	mstm->modified = true;

}



static void

nv50_msto_disable(struct drm_encoder *encoder)

{

	struct nv50_msto *msto = nv50_msto(encoder);

	struct nv50_mstc *mstc = msto->mstc;

	struct nv50_mstm *mstm = mstc->mstm;



	if (mstc->port)

		drm_dp_mst_reset_vcpi_slots(&mstm->mgr, mstc->port);



	mstm->outp->update(mstm->outp, msto->head->base.index, NULL, 0, 0);

	mstm->modified = true;

	msto->disabled = true;

}



static const struct drm_encoder_helper_funcs

nv50_msto_help = {

	.disable = nv50_msto_disable,

	.enable = nv50_msto_enable,

	.atomic_check = nv50_msto_atomic_check,

};



static void

nv50_msto_destroy(struct drm_encoder *encoder)

{

	struct nv50_msto *msto = nv50_msto(encoder);

	drm_encoder_cleanup(&msto->encoder);

	kfree(msto);

}



static const struct drm_encoder_funcs

nv50_msto = {

	.destroy = nv50_msto_destroy,

};



static int

nv50_msto_new(struct drm_device *dev, u32 heads, const char *name, int id,

	      struct nv50_msto **pmsto)

{

	struct nv50_msto *msto;

	int ret;



	if (!(msto = *pmsto = kzalloc(sizeof(*msto), GFP_KERNEL)))

		return -ENOMEM;



	ret = drm_encoder_init(dev, &msto->encoder, &nv50_msto,

			       DRM_MODE_ENCODER_DPMST, "%s-mst-%d", name, id);

	if (ret) {

		kfree(*pmsto);

		*pmsto = NULL;

		return ret;

	}



	drm_encoder_helper_add(&msto->encoder, &nv50_msto_help);

	msto->encoder.possible_crtcs = heads;

	return 0;

}



static struct drm_encoder *

nv50_mstc_atomic_best_encoder(struct drm_connector *connector,

			      struct drm_connector_state *connector_state)

{

	struct nv50_head *head = nv50_head(connector_state->crtc);

	struct nv50_mstc *mstc = nv50_mstc(connector);

	if (mstc->port) {

		struct nv50_mstm *mstm = mstc->mstm;

		return &mstm->msto[head->base.index]->encoder;

	}

	return NULL;

}



static struct drm_encoder *

nv50_mstc_best_encoder(struct drm_connector *connector)

{

	struct nv50_mstc *mstc = nv50_mstc(connector);

	if (mstc->port) {

		struct nv50_mstm *mstm = mstc->mstm;

		return &mstm->msto[0]->encoder;

	}

	return NULL;

}



static enum drm_mode_status

nv50_mstc_mode_valid(struct drm_connector *connector,

		     struct drm_display_mode *mode)

{

	return MODE_OK;

}



static int

nv50_mstc_get_modes(struct drm_connector *connector)

{

	struct nv50_mstc *mstc = nv50_mstc(connector);

	int ret = 0;



	mstc->edid = drm_dp_mst_get_edid(&mstc->connector, mstc->port->mgr, mstc->port);

	drm_mode_connector_update_edid_property(&mstc->connector, mstc->edid);

	if (mstc->edid) {

		ret = drm_add_edid_modes(&mstc->connector, mstc->edid);

		drm_edid_to_eld(&mstc->connector, mstc->edid);

	}



	if (!mstc->connector.display_info.bpc)

		mstc->connector.display_info.bpc = 8;



	if (mstc->native)

		drm_mode_destroy(mstc->connector.dev, mstc->native);

	mstc->native = nouveau_conn_native_mode(&mstc->connector);

	return ret;

}



static const struct drm_connector_helper_funcs

nv50_mstc_help = {

	.get_modes = nv50_mstc_get_modes,

	.mode_valid = nv50_mstc_mode_valid,

	.best_encoder = nv50_mstc_best_encoder,

	.atomic_best_encoder = nv50_mstc_atomic_best_encoder,

};



static enum drm_connector_status

nv50_mstc_detect(struct drm_connector *connector, bool force)

{

	struct nv50_mstc *mstc = nv50_mstc(connector);

	if (!mstc->port)

		return connector_status_disconnected;

	return drm_dp_mst_detect_port(connector, mstc->port->mgr, mstc->port);

}



static void

nv50_mstc_destroy(struct drm_connector *connector)

{

	struct nv50_mstc *mstc = nv50_mstc(connector);

	drm_connector_cleanup(&mstc->connector);

	kfree(mstc);

}



static const struct drm_connector_funcs

nv50_mstc = {

	.dpms = drm_atomic_helper_connector_dpms,

	.reset = nouveau_conn_reset,

	.detect = nv50_mstc_detect,

	.fill_modes = drm_helper_probe_single_connector_modes,

	.set_property = drm_atomic_helper_connector_set_property,

	.destroy = nv50_mstc_destroy,

	.atomic_duplicate_state = nouveau_conn_atomic_duplicate_state,

	.atomic_destroy_state = nouveau_conn_atomic_destroy_state,

	.atomic_set_property = nouveau_conn_atomic_set_property,

	.atomic_get_property = nouveau_conn_atomic_get_property,

};



static int

nv50_mstc_new(struct nv50_mstm *mstm, struct drm_dp_mst_port *port,

	      const char *path, struct nv50_mstc **pmstc)

{

	struct drm_device *dev = mstm->outp->base.base.dev;

	struct nv50_mstc *mstc;

	int ret, i;



	if (!(mstc = *pmstc = kzalloc(sizeof(*mstc), GFP_KERNEL)))

		return -ENOMEM;

	mstc->mstm = mstm;

	mstc->port = port;



	ret = drm_connector_init(dev, &mstc->connector, &nv50_mstc,

				 DRM_MODE_CONNECTOR_DisplayPort);

	if (ret) {

		kfree(*pmstc);

		*pmstc = NULL;

		return ret;

	}



	drm_connector_helper_add(&mstc->connector, &nv50_mstc_help);



	mstc->connector.funcs->reset(&mstc->connector);

	nouveau_conn_attach_properties(&mstc->connector);



	for (i = 0; i < ARRAY_SIZE(mstm->msto) && mstm->msto; i++)

		drm_mode_connector_attach_encoder(&mstc->connector, &mstm->msto[i]->encoder);



	drm_object_attach_property(&mstc->connector.base, dev->mode_config.path_property, 0);

	drm_object_attach_property(&mstc->connector.base, dev->mode_config.tile_property, 0);

	drm_mode_connector_set_path_property(&mstc->connector, path);

	return 0;

}



static void

nv50_mstm_cleanup(struct nv50_mstm *mstm)

{

	struct nouveau_drm *drm = nouveau_drm(mstm->outp->base.base.dev);

	struct drm_encoder *encoder;

	int ret;



	NV_ATOMIC(drm, "%s: mstm cleanup\n", mstm->outp->base.base.name);

	ret = drm_dp_check_act_status(&mstm->mgr);



	ret = drm_dp_update_payload_part2(&mstm->mgr);



	drm_for_each_encoder(encoder, mstm->outp->base.base.dev) {

		if (encoder->encoder_type == DRM_MODE_ENCODER_DPMST) {

			struct nv50_msto *msto = nv50_msto(encoder);

			struct nv50_mstc *mstc = msto->mstc;

			if (mstc && mstc->mstm == mstm)

				nv50_msto_cleanup(msto);

		}

	}



	mstm->modified = false;

}



static void

nv50_mstm_prepare(struct nv50_mstm *mstm)

{

	struct nouveau_drm *drm = nouveau_drm(mstm->outp->base.base.dev);

	struct drm_encoder *encoder;

	int ret;



	NV_ATOMIC(drm, "%s: mstm prepare\n", mstm->outp->base.base.name);

	ret = drm_dp_update_payload_part1(&mstm->mgr);



	drm_for_each_encoder(encoder, mstm->outp->base.base.dev) {

		if (encoder->encoder_type == DRM_MODE_ENCODER_DPMST) {

			struct nv50_msto *msto = nv50_msto(encoder);

			struct nv50_mstc *mstc = msto->mstc;

			if (mstc && mstc->mstm == mstm)

				nv50_msto_prepare(msto);

		}

	}

}



static void

nv50_mstm_hotplug(struct drm_dp_mst_topology_mgr *mgr)

{

	struct nv50_mstm *mstm = nv50_mstm(mgr);

	drm_kms_helper_hotplug_event(mstm->outp->base.base.dev);

}



static void

nv50_mstm_destroy_connector(struct drm_dp_mst_topology_mgr *mgr,

			    struct drm_connector *connector)

{

	struct nouveau_drm *drm = nouveau_drm(connector->dev);

	struct nv50_mstc *mstc = nv50_mstc(connector);



	drm_connector_unregister(&mstc->connector);



	drm_modeset_lock_all(drm->dev);

	drm_fb_helper_remove_one_connector(&drm->fbcon->helper, &mstc->connector);

	mstc->port = NULL;

	drm_modeset_unlock_all(drm->dev);



	drm_connector_unreference(&mstc->connector);

}



static void

nv50_mstm_register_connector(struct drm_connector *connector)

{

	struct nouveau_drm *drm = nouveau_drm(connector->dev);



	drm_modeset_lock_all(drm->dev);

	drm_fb_helper_add_one_connector(&drm->fbcon->helper, connector);

	drm_modeset_unlock_all(drm->dev);



	drm_connector_register(connector);

}



static struct drm_connector *

nv50_mstm_add_connector(struct drm_dp_mst_topology_mgr *mgr,

			struct drm_dp_mst_port *port, const char *path)

{

	struct nv50_mstm *mstm = nv50_mstm(mgr);

	struct nv50_mstc *mstc;

	int ret;



	ret = nv50_mstc_new(mstm, port, path, &mstc);

	if (ret) {

		if (mstc)

			mstc->connector.funcs->destroy(&mstc->connector);

		return NULL;

	}



	return &mstc->connector;

}



static const struct drm_dp_mst_topology_cbs

nv50_mstm = {

	.add_connector = nv50_mstm_add_connector,

	.register_connector = nv50_mstm_register_connector,

	.destroy_connector = nv50_mstm_destroy_connector,

	.hotplug = nv50_mstm_hotplug,

};



void

nv50_mstm_service(struct nv50_mstm *mstm)

{

	struct drm_dp_aux *aux = mstm->mgr.aux;

	bool handled = true;

	int ret;

	u8 esi[8] = {};



	while (handled) {

		ret = drm_dp_dpcd_read(aux, DP_SINK_COUNT_ESI, esi, 8);

		if (ret != 8) {

			drm_dp_mst_topology_mgr_set_mst(&mstm->mgr, false);

			return;

		}



		drm_dp_mst_hpd_irq(&mstm->mgr, esi, &handled);

		if (!handled)

			break;



		drm_dp_dpcd_write(aux, DP_SINK_COUNT_ESI + 1, &esi[1], 3);

	}

}



void

nv50_mstm_remove(struct nv50_mstm *mstm)

{

	if (mstm)

		drm_dp_mst_topology_mgr_set_mst(&mstm->mgr, false);

}



static int

nv50_mstm_enable(struct nv50_mstm *mstm, u8 dpcd, int state)

{
@@ -2872,6 +3362,20 @@ nv50_mstm_detect(struct nv50_mstm *mstm, u8 dpcd[8], int allow) 
	return mstm->mgr.mst_state;

}



static void

nv50_mstm_fini(struct nv50_mstm *mstm)

{

	if (mstm && mstm->mgr.mst_state)

		drm_dp_mst_topology_mgr_suspend(&mstm->mgr);

}



static void

nv50_mstm_init(struct nv50_mstm *mstm)

{

	if (mstm && mstm->mgr.mst_state)

		drm_dp_mst_topology_mgr_resume(&mstm->mgr);

}



static void

nv50_mstm_del(struct nv50_mstm **pmstm)

{
@@ -2889,17 +3393,36 @@ nv50_mstm_new(struct nouveau_encoder *outp, struct drm_dp_aux *aux, int aux_max, 
	const int max_payloads = hweight8(outp->dcb->heads);

	struct drm_device *dev = outp->base.base.dev;

	struct nv50_mstm *mstm;

	int ret;

	int ret, i;

	u8 dpcd;



	/* This is a workaround for some monitors not functioning

	 * correctly in MST mode on initial module load.  I think

	 * some bad interaction with the VBIOS may be responsible.

	 *

	 * A good ol' off and on again seems to work here ;)

	 */

	ret = drm_dp_dpcd_readb(aux, DP_DPCD_REV, &dpcd);

	if (ret >= 0 && dpcd >= 0x12)

		drm_dp_dpcd_writeb(aux, DP_MSTM_CTRL, 0);



	if (!(mstm = *pmstm = kzalloc(sizeof(*mstm), GFP_KERNEL)))

		return -ENOMEM;

	mstm->outp = outp;

	mstm->mgr.cbs = &nv50_mstm;



	ret = drm_dp_mst_topology_mgr_init(&mstm->mgr, dev->dev, aux, aux_max,

					   max_payloads, conn_base_id);

	if (ret)

		return ret;



	for (i = 0; i < max_payloads; i++) {

		ret = nv50_msto_new(dev, outp->dcb->heads, outp->base.base.name,

				    i, &mstm->msto[i]);

		if (ret)

			return ret;

	}



	return 0;

}
@@ -3364,10 +3887,20 @@ nv50_disp_atomic_commit_core(struct nouveau_drm *drm, u32 interlock) 
{

	struct nv50_disp *disp = nv50_disp(drm->dev);

	struct nv50_dmac *core = &disp->mast.base;

	struct nv50_mstm *mstm;

	struct drm_encoder *encoder;

	u32 *push;



	NV_ATOMIC(drm, "commit core %08x\n", interlock);



	drm_for_each_encoder(encoder, drm->dev) {

		if (encoder->encoder_type != DRM_MODE_ENCODER_DPMST) {

			mstm = nouveau_encoder(encoder)->dp.mstm;

			if (mstm && mstm->modified)

				nv50_mstm_prepare(mstm);

		}

	}



	if ((push = evo_wait(core, 5))) {

		evo_mthd(push, 0x0084, 1);

		evo_data(push, 0x80000000);
@@ -3383,6 +3916,14 @@ nv50_disp_atomic_commit_core(struct nouveau_drm *drm, u32 interlock) 
		) < 0)

			NV_ERROR(drm, "EVO timeout\n");

	}



	drm_for_each_encoder(encoder, drm->dev) {

		if (encoder->encoder_type != DRM_MODE_ENCODER_DPMST) {

			mstm = nouveau_encoder(encoder)->dp.mstm;

			if (mstm && mstm->modified)

				nv50_mstm_cleanup(mstm);

		}

	}

}



static void
@@ -3792,6 +4333,8 @@ nv50_disp_func = { 
void

nv50_display_fini(struct drm_device *dev)

{

	struct nouveau_encoder *nv_encoder;

	struct drm_encoder *encoder;

	struct drm_plane *plane;



	drm_for_each_plane(plane, dev) {
@@ -3800,6 +4343,13 @@ nv50_display_fini(struct drm_device *dev) 
			continue;

		nv50_wndw_fini(wndw);

	}



	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {

		if (encoder->encoder_type != DRM_MODE_ENCODER_DPMST) {

			nv_encoder = nouveau_encoder(encoder);

			nv50_mstm_fini(nv_encoder->dp.mstm);

		}

	}

}



int
@@ -3827,6 +4377,8 @@ nv50_display_init(struct drm_device *dev) 
			help = encoder->helper_private;

			if (help && help->dpms)

				help->dpms(encoder, DRM_MODE_DPMS_ON);



			nv50_mstm_init(nv_encoder->dp.mstm);

		}

	}