From: Sean Paul <seanpaul@chromium.org>
Date: Tue, 11 Jun 2019 12:08:21 -0400
Subject: drm/rockchip: Check for fast link training before enabling psr
Git-commit: ad309284a52be47c8b3126c9376358bf381861bc
Patch-mainline: 5.4-rc1
References: bnc#1151927 5.3.5

Once we start shutting off the link during PSR, we're going to want fast
training to work. If the display doesn't support fast training, don't
enable psr.

Changes in v2:
- None
Changes in v3:
- None
Changes in v4:
- None
Changes in v5:
- None

Link to v1: https://patchwork.freedesktop.org/patch/msgid/20190228210939.83386-3-sean@poorly.run
Link to v2: https://patchwork.freedesktop.org/patch/msgid/20190326204509.96515-2-sean@poorly.run
Link to v3: https://patchwork.freedesktop.org/patch/msgid/20190502194956.218441-9-sean@poorly.run
Link to v4: https://patchwork.freedesktop.org/patch/msgid/20190508160920.144739-8-sean@poorly.run

Cc: Zain Wang <wzz@rock-chips.com>
Cc: Tomasz Figa <tfiga@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190611160844.257498-8-sean@poorly.run
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/gpu/drm/bridge/analogix/analogix_dp_core.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -1035,16 +1035,17 @@ static int analogix_dp_commit(struct ana
 	if (ret)
 		return ret;
 
+	/* Check whether panel supports fast training */
+	ret = analogix_dp_fast_link_train_detection(dp);
+	if (ret)
+		dp->psr_enable = false;
+
 	if (dp->psr_enable) {
 		ret = analogix_dp_enable_sink_psr(dp);
 		if (ret)
 			return ret;
 	}
 
-	/* Check whether panel supports fast training */
-	ret =  analogix_dp_fast_link_train_detection(dp);
-	if (ret)
-		dp->psr_enable = false;
 
 	return ret;
 }