From: Arnd Bergmann <arnd@arndb.de>
Date: Thu, 15 Dec 2022 17:28:46 +0100
Subject: [PATCH] media: camss: csiphy-3ph: avoid undefined behavior
References: bsc#1012628
Patch-mainline: 6.2.3
Git-commit: 05fb9ace34b8645cb76f7e3a21b5c7b754329cae

[ Upstream commit 05fb9ace34b8645cb76f7e3a21b5c7b754329cae ]

Marking a case of the switch statement as unreachable means the
compiler treats it as undefined behavior, which is then caught by
an objtool warning:

drivers/media/platform/qcom/camss/camss-csiphy-3ph-1-0.o: warning: objtool: csiphy_lanes_enable() falls through to next function csiphy_lanes_disable()

Instead of simply continuing execution at a random place of the
driver, print a warning and return from to the caller, which
makes it possible to understand what happens and avoids the
warning.

Fixes: 53655d2a0ff2 ("media: camss: csiphy-3ph: add support for SM8250 CSI DPHY")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 drivers/media/platform/qcom/camss/camss-csiphy-3ph-1-0.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/qcom/camss/camss-csiphy-3ph-1-0.c b/drivers/media/platform/qcom/camss/camss-csiphy-3ph-1-0.c
index 451a4c9b..04baa804 100644
--- a/drivers/media/platform/qcom/camss/camss-csiphy-3ph-1-0.c
+++ b/drivers/media/platform/qcom/camss/camss-csiphy-3ph-1-0.c
@@ -429,7 +429,8 @@ static void csiphy_gen2_config_lanes(struct csiphy_device *csiphy,
 		array_size = ARRAY_SIZE(lane_regs_sm8250[0]);
 		break;
 	default:
-		unreachable();
+		WARN(1, "unknown cspi version\n");
+		return;
 	}
 
 	for (l = 0; l < 5; l++) {
-- 
2.35.3