From abfd45c251d8df3d881a973d9c9299418e396b81 Mon Sep 17 00:00:00 2001
From: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Date: Mon, 4 Nov 2019 13:32:46 -0500
Subject: drm/amd/display: Don't spin forever waiting for DMCUB phy/auto init
Git-commit: 56fc13fe6caa67e1017e048763c9eaa32330187b
Patch-mainline: v5.6-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

[Why]
It's an interface violation to use infinite loops within DMUB
service functions and we'll lock up the kernel by doing so.

[How]
Revert the function back to its intended functionality.
Move the infinite loops into DC/DM as necessary.

Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Sun peng Li <Sunpeng.Li@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c    | 6 ++++--
 drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c | 9 ++-------
 2 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c b/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
index b65b66025267..8d348a5f5599 100644
--- a/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
+++ b/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
@@ -112,8 +112,10 @@ void dc_dmub_srv_wait_phy_init(struct dc_dmub_srv *dc_dmub_srv)
 	struct dc_context *dc_ctx = dc_dmub_srv->ctx;
 	enum dmub_status status;
 
-	status = dmub_srv_wait_for_phy_init(dmub, 1000000);
-	if (status != DMUB_STATUS_OK)
+	status = dmub_srv_wait_for_phy_init(dmub, 10000000);
+	if (status != DMUB_STATUS_OK) {
 		DC_ERROR("Error waiting for DMUB phy init: status=%d\n",
 			 status);
+		ASSERT(0);
+	}
 }
diff --git a/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c b/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c
index 5ae1906ff1b1..60c574a39c6a 100644
--- a/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c
+++ b/drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c
@@ -400,19 +400,14 @@ enum dmub_status dmub_srv_wait_for_phy_init(struct dmub_srv *dmub,
 	if (!dmub->hw_init || !dmub->hw_funcs.is_phy_init)
 		return DMUB_STATUS_INVALID;
 
-/*	for (i = 0; i <= timeout_us; i += 10) {
+	for (i = 0; i <= timeout_us; i += 10) {
 		if (dmub->hw_funcs.is_phy_init(dmub))
 			return DMUB_STATUS_OK;
 
 		udelay(10);
-	}*/
-	while (!dmub->hw_funcs.is_phy_init(dmub)) {
-		ASSERT(i <= timeout_us);
-		i += 10;
-		udelay(10);
 	}
 
-	return DMUB_STATUS_OK;
+	return DMUB_STATUS_TIMEOUT;
 }
 
 enum dmub_status dmub_srv_wait_for_idle(struct dmub_srv *dmub,
-- 
2.28.0