[PATCH 00/14] drivers: use __maybe_unused to hide pm functions

[PATCH 00/14] drivers: use __maybe_unused to hide pm functions

[Arnd Bergmann]

I found many variations of the bug in these device drivers (and some
USB drivers I already send patches for in a separate series).

In each case, the power management operations structure conditionally
references suspend/resume functions, but the functions are hidden
in an incorrect #ifdef or not hidden at all.

We could try to correct the #ifdefs, but it seems easier to just
mark those functions as __maybe_unused, which has the same effect
but provides better compile-time test coverage and (subjectively)
looks a bit nicer.

I have a patch series that avoids all warnings in ARM randconfig
builds, and I have verified that all these patches fix a warning that
is still present in today's linux-next, and that they do not
introduce new warnings in any configuration I found.

Note that all these drivers are ARM specific, so I assume that
all portable drivers got fixed already when someone rand into
the problem on x86.

There are no dependencies between the patches, so I'd appreciate
subsystem maintainers to put them directly into their git trees.

	Arnd

Arnd Bergmann (14):
  pinctrl: at91: use __maybe_unused to hide pm functions
  irqchip: st: use __maybe_unused to hide st_irq_syscfg_resume
  power: ipaq-micro-battery: use __maybe_unused to hide pm functions
  power: pm2301-charger: use __maybe_unused to hide pm functions
  mfd: ipaq-micro: use __maybe_unused to hide pm functions
  dma: sirf: use __maybe_unused to hide pm functions
  hw_random: exynos: use __maybe_unused to hide pm functions
  scsi: mvumi: use __maybe_unused to hide pm functions
  amd-xgbe: use __maybe_unused to hide pm functions
  wireless: cw1200: use __maybe_unused to hide pm functions_
  input: spear-keyboard: use __maybe_unused to hide pm functions
  keyboard: snvs-pwrkey: use __maybe_unused to hide pm functions
  [media] omap3isp: use IS_ENABLED() to hide pm functions
  ASoC: rockchip: use __maybe_unused to hide st_irq_syscfg_resume

 drivers/char/hw_random/exynos-rng.c         | 10 ++++------
 drivers/dma/sirf-dma.c                      | 10 ++++------
 drivers/input/keyboard/snvs_pwrkey.c        |  4 ++--
 drivers/input/keyboard/spear-keyboard.c     |  6 ++----
 drivers/irqchip/irq-st.c                    |  2 +-
 drivers/media/platform/omap3isp/isp.c       | 13 +------------
 drivers/mfd/ipaq-micro.c                    |  2 +-
 drivers/net/ethernet/amd/xgbe/xgbe-main.c   |  6 ++----
 drivers/net/wireless/st/cw1200/cw1200_spi.c |  9 ++-------
 drivers/net/wireless/st/cw1200/pm.h         |  9 +++++++--
 drivers/pinctrl/pinctrl-at91-pio4.c         |  4 ++--
 drivers/power/ipaq_micro_battery.c          |  4 ++--
 drivers/power/pm2301_charger.c              | 22 ++++++----------------
 drivers/scsi/mvumi.c                        |  4 ++--
 sound/soc/rockchip/rockchip_spdif.c         |  4 ++--
 15 files changed, 40 insertions(+), 69 deletions(-)

-- 
2.7.0
Cc: herbert@gondor.apana.org.au
Cc: k.kozlowski@samsung.com
Cc: dan.j.williams@intel.com
Cc: vinod.koul@intel.com
Cc: baohua@kernel.org
Cc: dmitry.torokhov@gmail.com
Cc: tglx@linutronix.de
Cc: jason@lakedaemon.net
Cc: marc.zyngier@arm.com
Cc: laurent.pinchart@ideasonboard.com
Cc: mchehab@osg.samsung.com
Cc: lee.jones@linaro.org
Cc: kvalo@codeaurora.org
Cc: ludovic.desroches@atmel.com
Cc: linus.walleij@linaro.org
Cc: sre@kernel.org
Cc: dbaryshkov@gmail.com
Cc: JBottomley@odin.com
Cc: martin.petersen@oracle.com
Cc: broonie@kernel.org
Cc: linux-crypto@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: dmaengine@vger.kernel.org
Cc: linux-input@vger.kernel.org
Cc: linux-media@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-wireless@vger.kernel.org
Cc: linux-gpio@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: alsa-devel@alsa-project.org
Cc: linux-rockchip@lists.infradead.org

[PATCH 07/14] hw_random: exynos: use __maybe_unused to hide pm functions

[Arnd Bergmann]

The exynos random driver uses #ifdef to check for CONFIG_PM, but
then uses SIMPLE_DEV_PM_OPS, which leaves the references out when
CONFIG_PM_SLEEP is not defined, so we get a warning with
PM=y && PM_SLEEP=n:

drivers/char/hw_random/exynos-rng.c:166:12: error: 'exynos_rng_suspend' defined but not used [-Werror=unused-function]
drivers/char/hw_random/exynos-rng.c:171:12: error: 'exynos_rng_resume' defined but not used [-Werror=unused-function]

This removes the incorrect #ifdef and instead uses a __maybe_unused
annotation to let the compiler know it can silently drop
the function definition.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/char/hw_random/exynos-rng.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/char/hw_random/exynos-rng.c b/drivers/char/hw_random/exynos-rng.c
index 30cf4623184f..ada081232528 100644
--- a/drivers/char/hw_random/exynos-rng.c
+++ b/drivers/char/hw_random/exynos-rng.c
@@ -144,8 +144,7 @@ static int exynos_rng_probe(struct platform_device *pdev)
 	return devm_hwrng_register(&pdev->dev, &exynos_rng->rng);
 }
 
-#ifdef CONFIG_PM
-static int exynos_rng_runtime_suspend(struct device *dev)
+static int __maybe_unused exynos_rng_runtime_suspend(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct exynos_rng *exynos_rng = platform_get_drvdata(pdev);
@@ -155,7 +154,7 @@ static int exynos_rng_runtime_suspend(struct device *dev)
 	return 0;
 }
 
-static int exynos_rng_runtime_resume(struct device *dev)
+static int __maybe_unused exynos_rng_runtime_resume(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct exynos_rng *exynos_rng = platform_get_drvdata(pdev);
@@ -163,12 +162,12 @@ static int exynos_rng_runtime_resume(struct device *dev)
 	return clk_prepare_enable(exynos_rng->clk);
 }
 
-static int exynos_rng_suspend(struct device *dev)
+static int __maybe_unused exynos_rng_suspend(struct device *dev)
 {
 	return pm_runtime_force_suspend(dev);
 }
 
-static int exynos_rng_resume(struct device *dev)
+static int __maybe_unused exynos_rng_resume(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct exynos_rng *exynos_rng = platform_get_drvdata(pdev);
@@ -180,7 +179,6 @@ static int exynos_rng_resume(struct device *dev)
 
 	return exynos_rng_configure(exynos_rng);
 }
-#endif
 
 static const struct dev_pm_ops exynos_rng_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(exynos_rng_suspend, exynos_rng_resume)
-- 
2.7.0

Re: [PATCH 07/14] hw_random: exynos: use __maybe_unused to hide pm functions

[Krzysztof Kozlowski]

On 03.03.2016 00:58, Arnd Bergmann wrote:
> The exynos random driver uses #ifdef to check for CONFIG_PM, but
> then uses SIMPLE_DEV_PM_OPS, which leaves the references out when
> CONFIG_PM_SLEEP is not defined, so we get a warning with
> PM=y && PM_SLEEP=n:
> 
> drivers/char/hw_random/exynos-rng.c:166:12: error: 'exynos_rng_suspend' defined but not used [-Werror=unused-function]
> drivers/char/hw_random/exynos-rng.c:171:12: error: 'exynos_rng_resume' defined but not used [-Werror=unused-function]
> 
> This removes the incorrect #ifdef and instead uses a __maybe_unused
> annotation to let the compiler know it can silently drop
> the function definition.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>  drivers/char/hw_random/exynos-rng.c | 10 ++++------
>  1 file changed, 4 insertions(+), 6 deletions(-)
> 

Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

Best regards,
Krzysztof

Re: [PATCH 07/14] hw_random: exynos: use __maybe_unused to hide pm functions

[Herbert Xu]

On Wed, Mar 02, 2016 at 04:58:59PM +0100, Arnd Bergmann wrote:
> The exynos random driver uses #ifdef to check for CONFIG_PM, but
> then uses SIMPLE_DEV_PM_OPS, which leaves the references out when
> CONFIG_PM_SLEEP is not defined, so we get a warning with
> PM=y && PM_SLEEP=n:
> 
> drivers/char/hw_random/exynos-rng.c:166:12: error: 'exynos_rng_suspend' defined but not used [-Werror=unused-function]
> drivers/char/hw_random/exynos-rng.c:171:12: error: 'exynos_rng_resume' defined but not used [-Werror=unused-function]
> 
> This removes the incorrect #ifdef and instead uses a __maybe_unused
> annotation to let the compiler know it can silently drop
> the function definition.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Applied.
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt