From: Marek Vasut <marek.va...@gmail.com>

[ Upstream commit 2137a109a5e39c2bdccfffe65230ed3fadbaac0e ]

In case the upstream clock are not set, which can happen in case the
VC5 has no valid upstream clock, the $src variable is used uninited
by regmap_update_bits(). Check for this condition and return -EINVAL
in such case.

Note that in case the VC5 has no valid upstream clock, the VC5 can
not operate correctly. That is a hardware property of the VC5. The
internal oscilator present in some VC5 models is also considered
upstream clock.

Signed-off-by: Marek Vasut <marek.vasut+rene...@gmail.com>
Cc: Alexey Firago <alexey_fir...@mentor.com>
Cc: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
Cc: Stephen Boyd <sb...@kernel.org>
Cc: linux-renesas-soc@vger.kernel.org
[sb...@kernel.org: Added comment about probe preventing this from
happening in the first place]
Signed-off-by: Stephen Boyd <sb...@kernel.org>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/clk/clk-versaclock5.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk-versaclock5.c b/drivers/clk/clk-versaclock5.c
index decffb3826ec..a738af893532 100644
--- a/drivers/clk/clk-versaclock5.c
+++ b/drivers/clk/clk-versaclock5.c
@@ -262,8 +262,10 @@ static int vc5_mux_set_parent(struct clk_hw *hw, u8 index)
 
                if (vc5->clk_mux_ins == VC5_MUX_IN_XIN)
                        src = VC5_PRIM_SRC_SHDN_EN_XTAL;
-               if (vc5->clk_mux_ins == VC5_MUX_IN_CLKIN)
+               else if (vc5->clk_mux_ins == VC5_MUX_IN_CLKIN)
                        src = VC5_PRIM_SRC_SHDN_EN_CLKIN;
+               else /* Invalid; should have been caught by vc5_probe() */
+                       return -EINVAL;
        }
 
        return regmap_update_bits(vc5->regmap, VC5_PRIM_SRC_SHDN, mask, src);
-- 
2.19.1

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