[SRU][J:linux-xilinx-zynqmp][PATCH 1/1] drm: xlnx: dp: Reset DisplayPort IP

[Wei-Lin Chang]

From: Rohit Visavalia <rohit.visavalia at amd.com>

BugLink: https://bugs.launchpad.net/bugs/2114250

Assert DisplayPort reset signal before deasserting,
it is to clear out any registers programmed before booting kernel.

Signed-off-by: Rohit Visavalia <rohit.visavalia at amd.com>
Reviewed-by: Vishal Sagar <vishal.sagar at amd.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240216124043.1226713-1-rohit.visavalia@amd.com
(cherry picked from commit be318d01a90366029e181068e8857c6252e1fadc)
Signed-off-by: Wei-Lin Chang <weilin.chang at canonical.com>
---
 drivers/gpu/drm/xlnx/zynqmp_dp.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/xlnx/zynqmp_dp.c b/drivers/gpu/drm/xlnx/zynqmp_dp.c
index 2ebb8e367d15..a351b85cc6df 100644
--- a/drivers/gpu/drm/xlnx/zynqmp_dp.c
+++ b/drivers/gpu/drm/xlnx/zynqmp_dp.c
@@ -1922,6 +1922,10 @@ int zynqmp_dp_probe(struct platform_device *pdev)
 		return dev_err_probe(dp->dev, PTR_ERR(dp->reset),
 			"failed to get reset: %ld\n", PTR_ERR(dp->reset));
 
+	ret = zynqmp_dp_reset(dp, true);
+	if (ret < 0)
+		return ret;
+
 	ret = zynqmp_dp_reset(dp, false);
 	if (ret < 0)
 		return ret;
-- 
2.43.0