[PATCH] rtc: stm32: Use NOIRQ_SYSTEM_SLEEP_PM_OPS()

[Nathan Chancellor <nathan@kernel.org>]

After the switch to SET_NOIRQ_SYSTEM_SLEEP_PM_OPS() and a subsequent
fix, stm32_rtc_{suspend,resume}() are unused when CONFIG_PM_SLEEP is not
set because SET_NOIRQ_SYSTEM_SLEEP_PM_OPS() is a no-op in that
configuration:

  drivers/rtc/rtc-stm32.c:904:12: error: 'stm32_rtc_resume' defined but not used [-Werror=unused-function]
    904 | static int stm32_rtc_resume(struct device *dev)
        |            ^~~~~~~~~~~~~~~~
  drivers/rtc/rtc-stm32.c:894:12: error: 'stm32_rtc_suspend' defined but not used [-Werror=unused-function]
    894 | static int stm32_rtc_suspend(struct device *dev)
        |            ^~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors

The non-"SET_" version of this macro, NOIRQ_SYSTEM_SLEEP_PM_OPS(), is
designed to handle this situation by only assigning the callbacks when
CONFIG_PM_SLEEP is set while allowing the functions to appear used to
the compiler. Switch to that macro to resolve the warnings. There is no
functional change with this, as SET_NOIRQ_SYSTEM_SLEEP_PM_OPS() is
defined using NOIRQ_SYSTEM_SLEEP_PM_OPS() when CONFIG_PM_SLEEP is set.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
I am not sure what to do about a Fixes: tag for this change. I am not
sure how Arnd triggered the error/warning in commit a69c610e13e2 ("rtc:
stm32: remove incorrect #ifdef check"), since from what I can tell,
SET_NOIRQ_SYSTEM_SLEEP_PM_OPS() is only defined in terms of
NOIRQ_SYSTEM_SLEEP_PM_OPS() when CONFIG_PM_SLEEP is set, so I am not
sure how those functions could be absent in the source file but used in
NOIRQ_SYSTEM_SLEEP_PM_OPS() when CONFIG_PM_SLEEP is unset... I could be
missing something though.

However, I think this change should have been done as part of commit
fb9a7e5360dc ("rtc: stm32: change PM callbacks to "_noirq()"") because
the "SET_" macros are deprecated and that would have made Arnd's change
necessary so... assign an appropriate Fixes: tag based on that
information as you will :)
---
 drivers/rtc/rtc-stm32.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/rtc/rtc-stm32.c b/drivers/rtc/rtc-stm32.c
index 3ce4b3d08155..76753c71d92e 100644
--- a/drivers/rtc/rtc-stm32.c
+++ b/drivers/rtc/rtc-stm32.c
@@ -923,7 +923,7 @@ static int stm32_rtc_resume(struct device *dev)
 }
 
 static const struct dev_pm_ops stm32_rtc_pm_ops = {
-	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(stm32_rtc_suspend, stm32_rtc_resume)
+	NOIRQ_SYSTEM_SLEEP_PM_OPS(stm32_rtc_suspend, stm32_rtc_resume)
 };
 
 static struct platform_driver stm32_rtc_driver = {

---
base-commit: 4f3688dca15053555ade31a785a9c75837a64fb8
change-id: 20230815-rtc-stm32-unused-pm-funcs-90d84bc2c016

Best regards,
-- 
Nathan Chancellor <nathan@kernel.org>