Commit 8df1d0c0 authored by Ben Skeggs's avatar Ben Skeggs
Browse files

drm/nouveau/disp: semi-complete link training sequence even if display disappears 



Signed-off-by: default avatarBen Skeggs <bskeggs@redhat.com>
parent 4767fae8

drivers/gpu/drm/nouveau/core/engine/disp/dport.c

+32 −16
Original line number Diff line number Diff line
@@ -70,17 +70,10 @@ dp_set_link_config(struct dp_state *dp) 
	};

	u32 lnkcmp;

	u8 sink[2];

	int ret;



	DBG("%d lanes at %d KB/s\n", dp->link_nr, dp->link_bw);



	/* set desired link configuration on the sink */

	sink[0] = dp->link_bw / 27000;

	sink[1] = dp->link_nr;

	if (dp->dpcd[DPCD_RC02] & DPCD_RC02_ENHANCED_FRAME_CAP)

		sink[1] |= DPCD_LC01_ENHANCED_FRAME_EN;



	nv_wraux(dp->aux, DPCD_LC00, sink, 2);



	/* set desired link configuration on the source */

	if ((lnkcmp = dp->info.lnkcmp)) {

		if (dp->version < 0x30) {
@@ -96,10 +89,22 @@ dp_set_link_config(struct dp_state *dp) 
		nvbios_exec(&init);

	}



	return dp->func->lnk_ctl(dp->disp, dp->outp, dp->head,

	ret = dp->func->lnk_ctl(dp->disp, dp->outp, dp->head,

				dp->link_nr, dp->link_bw / 27000,

				dp->dpcd[DPCD_RC02] &

					 DPCD_RC02_ENHANCED_FRAME_CAP);

	if (ret) {

		ERR("lnk_ctl failed with %d\n", ret);

		return ret;

	}



	/* set desired link configuration on the sink */

	sink[0] = dp->link_bw / 27000;

	sink[1] = dp->link_nr;

	if (dp->dpcd[DPCD_RC02] & DPCD_RC02_ENHANCED_FRAME_CAP)

		sink[1] |= DPCD_LC01_ENHANCED_FRAME_EN;



	return nv_wraux(dp->aux, DPCD_LC00, sink, 2);

}



static void
@@ -294,8 +299,17 @@ nouveau_dp_train(struct nouveau_disp *disp, const struct nouveau_dp_func *func, 


	ret = nv_rdaux(dp->aux, 0x00000, dp->dpcd, sizeof(dp->dpcd));

	if (ret) {

		/* it's possible the display has been unplugged before we

		 * get here.  we still need to execute the full set of

		 * vbios scripts, and program the OR at a high enough

		 * frequency to satisfy the target mode.  failure to do

		 * so results at best in an UPDATE hanging, and at worst

		 * with PDISP running away to join the circus.

		 */

		dp->dpcd[1] = link_bw[0] / 27000;

		dp->dpcd[2] = 4;

		dp->dpcd[3] = 0x00;

		ERR("failed to read DPCD\n");

		return ret;

	}



	/* adjust required bandwidth for 8B/10B coding overhead */
@@ -328,8 +342,10 @@ nouveau_dp_train(struct nouveau_disp *disp, const struct nouveau_dp_func *func, 
			    !dp_link_train_eq(dp))

				break;

		} else

		if (ret >= 1) {

			/* dp_set_link_config() handled training */

		if (ret) {

			/* dp_set_link_config() handled training, or

			 * we failed to communicate with the sink.

			 */

			break;

		}
@@ -344,5 +360,5 @@ nouveau_dp_train(struct nouveau_disp *disp, const struct nouveau_dp_func *func, 


	/* execute post-train script from vbios */

	dp_link_train_fini(dp);

	return true;

	return (ret < 0) ? false : true;

}