RE: [PATCH] tpm/tpm_crb: mark PM functions as __maybe_unused

From: Winkler, Tomas
Date: Mon Mar 20 2017 - 08:13:54 EST


>
> When CONFIG_PM_SLEEP is disabled, we get a warning about unused
> functions:
>
> drivers/char/tpm/tpm_crb.c:551:12: error: 'crb_pm_resume' defined but not
> used [-Werror=unused-function]
> drivers/char/tpm/tpm_crb.c:540:12: error: 'crb_pm_suspend' defined but not
> used [-Werror=unused-function]
>
Note that the runtime_pm functions are not affected by this issue the macro SET_RUNTIME_PM_OPS
is under CONFIG_PM. This patch does more than described.

> We could solve this with more sophistated #ifdefs, but a simpler and safer way
> is to just mark them as __maybe_unused.

>
> Fixes: 848efcfb560c ("tpm/tpm_crb: enter the low power state upon device
> suspend")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> drivers/char/tpm/tpm_crb.c | 11 ++++-------
> 1 file changed, 4 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c index
> 1dfc37e33c02..15f1118982a6 100644
> --- a/drivers/char/tpm/tpm_crb.c
> +++ b/drivers/char/tpm/tpm_crb.c
> @@ -519,8 +519,7 @@ static int crb_acpi_remove(struct acpi_device *device)
> return 0;
> }
>
> -#ifdef CONFIG_PM
> -static int crb_pm_runtime_suspend(struct device *dev)
> +static __maybe_unused int crb_pm_runtime_suspend(struct device *dev)
> {
> struct tpm_chip *chip = dev_get_drvdata(dev);
> struct crb_priv *priv = dev_get_drvdata(&chip->dev); @@ -528,7
> +527,7 @@ static int crb_pm_runtime_suspend(struct device *dev)
> return crb_go_idle(dev, priv);
> }
>
> -static int crb_pm_runtime_resume(struct device *dev)
> +static __maybe_unused int crb_pm_runtime_resume(struct device *dev)
> {
> struct tpm_chip *chip = dev_get_drvdata(dev);
> struct crb_priv *priv = dev_get_drvdata(&chip->dev); @@ -536,7
> +535,7 @@ static int crb_pm_runtime_resume(struct device *dev)
> return crb_cmd_ready(dev, priv);
> }
>
> -static int crb_pm_suspend(struct device *dev)
> +static __maybe_unused int crb_pm_suspend(struct device *dev)
> {
> int ret;
>
> @@ -547,7 +546,7 @@ static int crb_pm_suspend(struct device *dev)
> return crb_pm_runtime_suspend(dev);
> }

It's enough to
#endif /* CONFIG_PM */
#ifdef CONFIG_PM_SLEEP
> -static int crb_pm_resume(struct device *dev)
> +static __maybe_unused int crb_pm_resume(struct device *dev)
> {
> int ret;
>
> @@ -558,8 +557,6 @@ static int crb_pm_resume(struct device *dev)
> return tpm_pm_resume(dev);
> }
>
> -#endif /* CONFIG_PM */
And
#endif CONFIG_PM_SLEEP

> -
> static const struct dev_pm_ops crb_pm = {
> SET_SYSTEM_SLEEP_PM_OPS(crb_pm_suspend, crb_pm_resume)
> SET_RUNTIME_PM_OPS(crb_pm_runtime_suspend,
> crb_pm_runtime_resume, NULL)
> --
> 2.9.0