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

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>

diff --git a/drivers/mfd/madera-core.c b/drivers/mfd/madera-core.c
index bdbd5bfc9714564a76186c33780937c7e9f34cdd..2f74a8c644a32a150302ac931333c5920a04c86c 100644 (file)
--- a/drivers/mfd/madera-core.c
+++ b/drivers/mfd/madera-core.c
@@ -456,7 +456,7 @@ 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;
 
@@ -670,7 +670,7 @@ 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;