mfd: madera: Work around false-positive -Wininitialized warning

[ Upstream commit 364752aa0c6ab0a06a2d5bfdb362c1ca407f1a30 ]

clang-21 warns about one uninitialized variable getting dereferenced
in madera_dev_init:

drivers/mfd/madera-core.c:739:10: error: variable 'mfd_devs' is uninitialized when used here [-Werror,-Wuninitialized]
  739 |                               mfd_devs, n_devs,
      |                               ^~~~~~~~
drivers/mfd/madera-core.c:459:33: note: initialize the variable 'mfd_devs' to silence this warning
  459 |         const struct mfd_cell *mfd_devs;
      |                                        ^
      |                                         = NULL

The code is actually correct here because n_devs is only nonzero
when mfd_devs is a valid pointer, but this is impossible for the
compiler to see reliably.

Change the logic to check for the pointer as well, to make this easier
for the compiler to follow.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20250807071932.4085458-1-arnd@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/mfd/madera-core.c b/drivers/mfd/madera-core.c
index 29540cbf75934030660483e99190db734b0ce62f..bfd116f5a58d030515ddd85294d80c6bf898321c 100644 (file)
--- a/drivers/mfd/madera-core.c
+++ b/drivers/mfd/madera-core.c
@@ -431,7 +431,7 @@ int madera_dev_init(struct madera *madera)
        struct device *dev = madera->dev;
        unsigned int hwid;
        int (*patch_fn)(struct madera *) = NULL;
-       const struct mfd_cell *mfd_devs;
+       const struct mfd_cell *mfd_devs = NULL;
        int n_devs = 0;
        int i, ret;
 
@@ -616,7 +616,7 @@ int madera_dev_init(struct madera *madera)
                goto err_reset;
        }
 
-       if (!n_devs) {
+       if (!n_devs || !mfd_devs) {
                dev_err(madera->dev, "Device ID 0x%x not a %s\n", hwid,
                        madera->type_name);
                ret = -ENODEV;