ARM: sun9i: smp: fix return code check of of_property_match_string

[ Upstream commit 643fe70e7bcdcc9e2d96952f7fc2bab56385cce5 ]

of_property_match_string returns an int; either an index from 0 or
greater if successful or negative on failure. Even it's very
unlikely that the DT CPU node contains multiple enable-methods
these checks should be fixed.

This patch was inspired by the work of Nick Desaulniers.

Link: https://lore.kernel.org/lkml/20230516-sunxi-v1-1-ac4b9651a8c1@google.com/T/
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Link: https://lore.kernel.org/r/20231228193903.9078-2-wahrenst@gmx.net
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/arch/arm/mach-sunxi/mc_smp.c b/arch/arm/mach-sunxi/mc_smp.c
index 6ec3445..277f6aa 100644 (file)
--- a/arch/arm/mach-sunxi/mc_smp.c
+++ b/arch/arm/mach-sunxi/mc_smp.c
@@ -803,12 +803,12 @@ static int __init sunxi_mc_smp_init(void)
        for (i = 0; i < ARRAY_SIZE(sunxi_mc_smp_data); i++) {
                ret = of_property_match_string(node, "enable-method",
                                               sunxi_mc_smp_data[i].enable_method);
-               if (!ret)
+               if (ret >= 0)
                        break;
        }
 
        of_node_put(node);
-       if (ret)
+       if (ret < 0)
                return -ENODEV;
 
        is_a83t = sunxi_mc_smp_data[i].is_a83t;