[PATCH] clk: qoriq: avoid formwat string warning

From: Arnd Bergmann

Date: Fri Mar 20 2026 - 11:36:11 EST


From: Arnd Bergmann <arnd@xxxxxxxx>

clang-22 warns about the use of non-variadic format arguments passed into
snprintf():

drivers/clk/clk-qoriq.c:925:39: error: diagnostic behavior may be improved by adding the
'format(printf, 7, 8)' attribute to the declaration of 'create_mux_common' [-Werror,-Wmissing-format-attribute]
910 | static struct clk * __init create_mux_common(struct clockgen *cg,
| __attribute__((format(printf, 7, 8)))
911 | struct mux_hwclock *hwc,
912 | const struct clk_ops *ops,
913 | unsigned long min_rate,
914 | unsigned long max_rate,
915 | unsigned long pct80_rate,
916 | const char *fmt, int idx)
917 | {
918 | struct clk_init_data init = {};
919 | struct clk *clk;
920 | const struct clockgen_pll_div *div;
921 | const char *parent_names[NUM_MUX_PARENTS];
922 | char name[32];
923 | int i, j;
924 |
925 | snprintf(name, sizeof(name), fmt, idx);
| ^
drivers/clk/clk-qoriq.c:910:28: note: 'create_mux_common' declared here
910 | static struct clk * __init create_mux_common(struct clockgen *cg,

Rework this to pass the 'int idx' as a varargs argument, allowing the
format string to be verified at the caller location.

Fixes: 0dfc86b3173f ("clk: qoriq: Move chip-specific knowledge into driver")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/clk/clk-qoriq.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/clk/clk-qoriq.c b/drivers/clk/clk-qoriq.c
index f05631e55310..2524c5c0eb46 100644
--- a/drivers/clk/clk-qoriq.c
+++ b/drivers/clk/clk-qoriq.c
@@ -907,13 +907,11 @@ static const struct clockgen_pll_div *get_pll_div(struct clockgen *cg,
return &cg->pll[pll].div[div];
}

-static struct clk * __init create_mux_common(struct clockgen *cg,
- struct mux_hwclock *hwc,
- const struct clk_ops *ops,
- unsigned long min_rate,
- unsigned long max_rate,
- unsigned long pct80_rate,
- const char *fmt, int idx)
+static struct clk * __init __printf(7, 8)
+create_mux_common(struct clockgen *cg, struct mux_hwclock *hwc,
+ const struct clk_ops *ops, unsigned long min_rate,
+ unsigned long max_rate, unsigned long pct80_rate,
+ const char *fmt, ...)
{
struct clk_init_data init = {};
struct clk *clk;
@@ -921,8 +919,11 @@ static struct clk * __init create_mux_common(struct clockgen *cg,
const char *parent_names[NUM_MUX_PARENTS];
char name[32];
int i, j;
+ va_list args;

- snprintf(name, sizeof(name), fmt, idx);
+ va_start(args, fmt);
+ vsnprintf(name, sizeof(name), fmt, args);
+ va_end(args);

for (i = 0, j = 0; i < NUM_MUX_PARENTS; i++) {
unsigned long rate;
--
2.39.5