drm/nouveau/disp: semi-complete link training sequence even if display disappears (8df1d0c0) · Commits · e / devices / android_kernel_teracube_2e

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;
		}