From: Konrad Dybcio <konrad.dybcio@linaro.org>
Date: Mon, 17 Apr 2023 17:41:08 +0200
Subject: [PATCH] drm/panel: novatek-nt35950: Only unregister DSI1 if it exists
References: bsc#1012628
Patch-mainline: 6.3.2
Git-commit: a50be876f4fe2349dc8b056a49d87f69c944570f

[ Upstream commit a50be876f4fe2349dc8b056a49d87f69c944570f ]

Commit 5dd45b66742a ("drm/panel: novatek-nt35950: Improve error handling")
introduced logic to unregister DSI1 on any sort of probe failure, as
that's not done automatically by kernel APIs.

It did not however account for cases where only one DSI host is used.
Fix that.

Fixes: 5dd45b66742a ("drm/panel: novatek-nt35950: Improve error handling")
Reported-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230417-topic-maple_panel_fixup-v1-1-07c8db606f5e@linaro.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/gpu/drm/panel/panel-novatek-nt35950.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-novatek-nt35950.c b/drivers/gpu/drm/panel/panel-novatek-nt35950.c
index 7498fc62..8b108ac8 100644
--- a/drivers/gpu/drm/panel/panel-novatek-nt35950.c
+++ b/drivers/gpu/drm/panel/panel-novatek-nt35950.c
@@ -586,7 +586,8 @@ static int nt35950_probe(struct mipi_dsi_device *dsi)
 
 	ret = drm_panel_of_backlight(&nt->panel);
 	if (ret) {
-		mipi_dsi_device_unregister(nt->dsi[1]);
+		if (num_dsis == 2)
+			mipi_dsi_device_unregister(nt->dsi[1]);
 
 		return dev_err_probe(dev, ret, "Failed to get backlight\n");
 	}
@@ -606,7 +607,8 @@ static int nt35950_probe(struct mipi_dsi_device *dsi)
 		ret = mipi_dsi_attach(nt->dsi[i]);
 		if (ret < 0) {
 			/* If we fail to attach to either host, we're done */
-			mipi_dsi_device_unregister(nt->dsi[1]);
+			if (num_dsis == 2)
+				mipi_dsi_device_unregister(nt->dsi[1]);
 
 			return dev_err_probe(dev, ret,
 					     "Cannot attach to DSI%d host.\n", i);
-- 
2.35.3