Re: [PATCH] mmc: sdhci-esdhc-imx: avoid unused function warnings

[Arnd Bergmann <arnd@arndb.de>]

On Tuesday, July 26, 2016 2:32:34 PM CEST Arnd Bergmann wrote:
> The driver has just gained a slightly incorrect pm-sleep implementation that causes
> warnings when CONFIG_PM is set but CONFIG_PM_SLEEP is not:
> 
> drivers/mmc/host/sdhci-esdhc-imx.c:1302:12: error: 'sdhci_esdhc_resume' defined but not used [-Werror=unused-function]
>  static int sdhci_esdhc_resume(struct device *dev)
>             ^~~~~~~~~~~~~~~~~~
> drivers/mmc/host/sdhci-esdhc-imx.c:1297:12: error: 'sdhci_esdhc_suspend' defined but not used [-Werror=unused-function]
>  static int sdhci_esdhc_suspend(struct device *dev)
> 
> This replaces the incorrect #ifdef with a __maybe_unused annotation that does
> the right thing in all configurations and is more readable.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Fixes: b70d0b3b5b29 ("mmc: sdhci-esdhc-imx: add esdhc specific suspend resume callback")


It turns out that the version of the fix above requires another change
below. Fixing up the #ifdef as Ulf suggested would not require that,
but on the other hand, we generally don't hide declarations in header
files unless there is an alternative in the #else path, so we
probably want to do that anyway.

We could either fold this patch into the one I sent already, or
have this one applied separately and use the version that Ulf
preferred for the warning fix. I can send whichever we decide to
do with a proper changelog once we have consensus.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/drivers/mmc/host/sdhci-pltfm.h b/drivers/mmc/host/sdhci-pltfm.h
index d38053bf9e4d..173ef914281d 100644
--- a/drivers/mmc/host/sdhci-pltfm.h
+++ b/drivers/mmc/host/sdhci-pltfm.h
@@ -109,9 +109,9 @@ static inline void *sdhci_pltfm_priv(struct sdhci_pltfm_host *host)
 	return (void *)host->private;
 }
 
-#ifdef CONFIG_PM
 extern int sdhci_pltfm_suspend(struct device *dev);
 extern int sdhci_pltfm_resume(struct device *dev);
+#ifdef CONFIG_PM
 extern const struct dev_pm_ops sdhci_pltfm_pmops;
 #define SDHCI_PLTFM_PMOPS (&sdhci_pltfm_pmops)
 #else
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 0411c9f36461..9a77cb009fc8 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -686,12 +686,10 @@ void sdhci_set_bus_width(struct sdhci_host *host, int width);
 void sdhci_reset(struct sdhci_host *host, u8 mask);
 void sdhci_set_uhs_signaling(struct sdhci_host *host, unsigned timing);
 
-#ifdef CONFIG_PM
 extern int sdhci_suspend_host(struct sdhci_host *host);
 extern int sdhci_resume_host(struct sdhci_host *host);
 extern void sdhci_enable_irq_wakeups(struct sdhci_host *host);
 extern int sdhci_runtime_suspend_host(struct sdhci_host *host);
 extern int sdhci_runtime_resume_host(struct sdhci_host *host);
-#endif
 
 #endif /* __SDHCI_HW_H */