[PATCH 0/3] ARM: omap: randconfig warning fixes

Hi Tony,

Here are three patches to fix the remaining warnings I get
in OMAP randconfig builds. The problems are all harmless,
and the patches are just shutting up the compiler, but I
think it's still worthwhile to include them to reduce the
noise.

	Arnd

The omap_generic_init() and omap_hwmod_init_postsetup() functions are
used in the initialization for all OMAP2+ SoC types, but in the
extreme case that those are all disabled, we get a warning about
unused code:

arch/arm/mach-omap2/io.c:412:123: error: 'omap_hwmod_init_postsetup' defined but not used [-Werror=unused-function]
arch/arm/mach-omap2/board-generic.c:30:123: error: 'omap_generic_init' defined but not used [-Werror=unused-function]

This annotates both as __maybe_unused to shut up that warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/arm/mach-omap2/board-generic.c | 2 +-
 arch/arm/mach-omap2/io.c            | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-omap2/board-generic.c b/arch/arm/mach-omap2/board-generic.c
index bab814d2f37d..d75ec64ae0b5 100644
--- a/arch/arm/mach-omap2/board-generic.c
+++ b/arch/arm/mach-omap2/board-generic.c

@@ -28,7 +28,7 @@ static const struct of_device_id omap_dt_match_table[] __initconst = {
 	{ }
 };
 
-static void __init omap_generic_init(void)
+static void __init __maybe_unused omap_generic_init(void)
 {
 	omapdss_early_init_of();
 

diff --git a/arch/arm/mach-omap2/io.c b/arch/arm/mach-omap2/io.c
index 3c87e40650cf..f192fc7fd4f7 100644
--- a/arch/arm/mach-omap2/io.c
+++ b/arch/arm/mach-omap2/io.c

@@ -409,7 +409,7 @@ static int _set_hwmod_postsetup_state(struct omap_hwmod *oh, void *data)
 	return omap_hwmod_set_postsetup_state(oh, *(u8 *)data);
 }
 
-static void __init omap_hwmod_init_postsetup(void)
+static void __init __maybe_unused omap_hwmod_init_postsetup(void)
 {
 	u8 postsetup_state;
 

-- 
2.7.0

* Arnd Bergmann [off-list ref] [160223 05:58]:

The omap_generic_init() and omap_hwmod_init_postsetup() functions are
used in the initialization for all OMAP2+ SoC types, but in the
extreme case that those are all disabled, we get a warning about
unused code:

arch/arm/mach-omap2/io.c:412:123: error: 'omap_hwmod_init_postsetup' defined but not used [-Werror=unused-function]
arch/arm/mach-omap2/board-generic.c:30:123: error: 'omap_generic_init' defined but not used [-Werror=unused-function]

This annotates both as __maybe_unused to shut up that warning.

Looks OK to me:

Acked-by: Tony Lindgren <tony@atomide.com>

The osk_mistral_init() contains code that is only compiled when
CONFIG_PM is set, but it uses a variable that is declared outside
of the #ifdef:

arch/arm/mach-omap1/board-osk.c: In function 'osk_mistral_init':
arch/arm/mach-omap1/board-osk.c:513:7: warning: unused variable 'ret' [-Wunused-variable]

This puts the variable in the same #ifdef to avoid the warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/arm/mach-omap1/board-osk.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/mach-omap1/board-osk.c b/arch/arm/mach-omap1/board-osk.c
index 209aecb0df68..fcc5c0650429 100644
--- a/arch/arm/mach-omap1/board-osk.c
+++ b/arch/arm/mach-omap1/board-osk.c

@@ -510,7 +510,9 @@ static void __init osk_mistral_init(void)
 	 */
 	omap_cfg_reg(N15_1610_MPUIO2);
 	if (gpio_request(OMAP_MPUIO(2), "wakeup") == 0) {
+#ifdef	CONFIG_PM
 		int ret = 0;
+#endif
 		int irq = gpio_to_irq(OMAP_MPUIO(2));
 
 		gpio_direction_input(OMAP_MPUIO(2));

-- 
2.7.0

* Arnd Bergmann [off-list ref] [160223 05:58]:

Let's just remove the #ifdef CONFIG_PM in osk_mistral_init()
instead. That's for the wake-up button and I'm not aware
of any other use cases for that button.

Regards,

Tony

On Tue, Feb 23, 2016 at 02:57:52PM +0100, Arnd Bergmann wrote:

The osk_mistral_init() contains code that is only compiled when
CONFIG_PM is set, but it uses a variable that is declared outside
of the #ifdef:

arch/arm/mach-omap1/board-osk.c: In function 'osk_mistral_init':
arch/arm/mach-omap1/board-osk.c:513:7: warning: unused variable 'ret' [-Wunused-variable]

This puts the variable in the same #ifdef to avoid the warning.

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

Acked-by: Aaro Koskinen <aaro.koskinen@iki.fi>

A.

The modem pm handler in the ams-delta board uses regulator_enable()
but does not check for a successful return code:

board-ams-delta.c:521:3: error: ignoring return value of 'regulator_enable', declared with attribute warn_unused_result [-Werror=unused-result]

It is not easy to propagate that return code to the callers in
uart_configure_port/uart_suspend_port/uart_resume_port, unless
we change all UART drivers, and it is unclear what those would
do with the return code.

Instead, this patch uses a runtime warning to replace the
compiletime warning. I have checked that the regulator in question
is hardcoded to a fixed-voltage GPIO regulator, and that should
never fail to get enabled if I understand the code right.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/arm/mach-omap1/board-ams-delta.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-omap1/board-ams-delta.c b/arch/arm/mach-omap1/board-ams-delta.c
index 6613a6ff5dbc..6cbc69c92913 100644
--- a/arch/arm/mach-omap1/board-ams-delta.c
+++ b/arch/arm/mach-omap1/board-ams-delta.c

@@ -510,6 +510,7 @@ static void __init ams_delta_init(void)
 static void modem_pm(struct uart_port *port, unsigned int state, unsigned old)
 {
 	struct modem_private_data *priv = port->private_data;
+	int ret;
 
 	if (IS_ERR(priv->regulator))
 		return;

@@ -518,9 +519,16 @@ static void modem_pm(struct uart_port *port, unsigned int state, unsigned old)
 		return;
 
 	if (state == 0)
-		regulator_enable(priv->regulator);
+		ret = regulator_enable(priv->regulator);
 	else if (old == 0)
-		regulator_disable(priv->regulator);
+		ret = regulator_disable(priv->regulator);
+	else
+		ret = 0;
+
+	if (ret)
+		dev_warn(port->dev,
+			 "ams_delta modem_pm: failed to %sable regulator: %d\n",
+			 state ? "dis" : "en", ret);
 }
 
 static struct plat_serial8250_port ams_delta_modem_ports[] = {

-- 
2.7.0

* Arnd Bergmann [off-list ref] [160223 05:58]:

The modem pm handler in the ams-delta board uses regulator_enable()
but does not check for a successful return code:

board-ams-delta.c:521:3: error: ignoring return value of 'regulator_enable', declared with attribute warn_unused_result [-Werror=unused-result]

It is not easy to propagate that return code to the callers in
uart_configure_port/uart_suspend_port/uart_resume_port, unless
we change all UART drivers, and it is unclear what those would
do with the return code.

Instead, this patch uses a runtime warning to replace the
compiletime warning. I have checked that the regulator in question
is hardcoded to a fixed-voltage GPIO regulator, and that should
never fail to get enabled if I understand the code right.

Looks OK to me:

Acked-by: Tony Lindgren <tony@atomide.com>

quoted

It is not easy to propagate that return code to the callers in
uart_configure_port/uart_suspend_port/uart_resume_port, unless
we change all UART drivers, and it is unclear what those would
do with the return code.

Instead, this patch uses a runtime warning to replace the
compiletime warning. I have checked that the regulator in question
is hardcoded to a fixed-voltage GPIO regulator, and that should
never fail to get enabled if I understand the code right.  

Looks OK to me:

If it was a concern for a real driver I think I'd perform a hangup on the
port at that moment. That's what happens if for example you hot unplug a
serial port which would be approximately the same as finding out you
can't power it back up.

Alan

On Tue, Feb 23, 2016 at 02:57:53PM +0100, Arnd Bergmann wrote:

The modem pm handler in the ams-delta board uses regulator_enable()
but does not check for a successful return code:

board-ams-delta.c:521:3: error: ignoring return value of 'regulator_enable', declared with attribute warn_unused_result [-Werror=unused-result]

It is not easy to propagate that return code to the callers in
uart_configure_port/uart_suspend_port/uart_resume_port, unless
we change all UART drivers, and it is unclear what those would
do with the return code.

Instead, this patch uses a runtime warning to replace the
compiletime warning. I have checked that the regulator in question
is hardcoded to a fixed-voltage GPIO regulator, and that should
never fail to get enabled if I understand the code right.

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

Acked-by: Aaro Koskinen <aaro.koskinen@iki.fi>

A.