[PATCH AUTOSEL 5.3 18/87] drm/rockchip: Check for fast link training before enabling psr

[Sasha Levin]

From: Sean Paul <seanpaul at chromium.org>

[ Upstream commit ad309284a52be47c8b3126c9376358bf381861bc ]

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

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index 3f7f4880be091..37bd541166a5e 100644
--- 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 analogix_dp_device *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;
+
 	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;
 }
-- 
2.20.1