From: Philippe CORNU <philippe.cornu@st.com>
Date: Tue, 17 Apr 2018 13:34:41 +0200
Subject: drm/stm: ltdc: fix deferred endpoint management
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Git-commit: c2af73645d3a67cc2e4a750179048a4c6d5110a1
Patch-mainline: v4.18-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

When a driver related to one of the endpoints is deferred
due to probe dependencies (i2c, spi...) but the other one
is ready, ltdc probe continues and the deferred driver
will never be probed again.

The fix consists in waiting for all deferred endpoints before
continuing the ltdc probe.

Signed-off-by: Philippe Cornu <philippe.cornu@st.com>
Reviewed-by: Yannick Fertré <yannick.fertre@st.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180417113441.8214-1-philippe.cornu@st.com

Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/stm/ltdc.c |   11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -987,14 +987,13 @@ int ltdc_load(struct drm_device *ddev)
 						  &bridge[i]);
 
 		/*
-		 * If at least one endpoint is ready, continue probing,
-		 * else if at least one endpoint is -EPROBE_DEFER and
-		 * there is no previous ready endpoints, defer probing.
+		 * If at least one endpoint is -EPROBE_DEFER, defer probing,
+		 * else if at least one endpoint is ready, continue probing.
 		 */
-		if (!ret)
+		if (ret == -EPROBE_DEFER)
+			return ret;
+		else if (!ret)
 			endpoint_not_ready = 0;
-		else if (ret == -EPROBE_DEFER && endpoint_not_ready)
-			endpoint_not_ready = -EPROBE_DEFER;
 	}
 
 	if (endpoint_not_ready)