From: Arnd Bergmann <arnd@xxxxxxxx> 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@xxxxxxxx> --- 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 451a4c9b3d30..04baa80494c6 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++) { -- 2.35.1