Re: [PATCH] ARM: EXYNOS: cpuidle: Fix build breakage on !SMP

[Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>]

Hi,

On Wednesday, February 04, 2015 11:27:26 AM Krzysztof Kozlowski wrote:
> The Exynos cpuidle driver has coupled cpuidle built-in so it cannot be
> built without SMP:
> 
> arch/arm/mach-exynos/pm.c: In function ‘exynos_cpu0_enter_aftr’:
> arch/arm/mach-exynos/pm.c:246:4: error: implicit declaration of function ‘arch_send_wakeup_ipi_mask’ [-Werror=implicit-function-declaration]
> arch/arm/mach-exynos/built-in.o: In function `exynos_pre_enter_aftr':
> ../arch/arm/mach-exynos/pm.c:300: undefined reference to `cpu_boot_reg_base'
> arch/arm/mach-exynos/built-in.o: In function `exynos_cpu1_powerdown':
> ../arch/arm/mach-exynos/pm.c:282: undefined reference to `exynos_cpu_power_down'
> 
> Make the cpuidle driver depending on SMP because this will be the
> fastest way to fix build break without adding a bunch of ifdefs in few
> places.

There shouldn't be a lot of new ifdefs (please see below) and I would
very much prefer for cpuidle to stay supported also on UP kernels.

> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
> ---
>  arch/arm/mach-exynos/pm.c   | 2 ++
>  drivers/cpuidle/Kconfig.arm | 3 ++-
>  2 files changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/mach-exynos/pm.c b/arch/arm/mach-exynos/pm.c
> index e6209dadc00d..17db00ff7f3a 100644
> --- a/arch/arm/mach-exynos/pm.c
> +++ b/arch/arm/mach-exynos/pm.c
> @@ -181,6 +181,7 @@ void exynos_enter_aftr(void)
>  	cpu_pm_exit();
>  }
>  
> +#ifdef CONFIG_ARM_EXYNOS_CPUIDLE
>  static atomic_t cpu1_wakeup = ATOMIC_INIT(0);
>  
>  static int exynos_cpu0_enter_aftr(void)
> @@ -302,3 +303,4 @@ struct cpuidle_exynos_data cpuidle_coupled_exynos_data = {
>  	.pre_enter_aftr		= exynos_pre_enter_aftr,
>  	.post_enter_aftr		= exynos_post_enter_aftr,
>  };
> +#endif /* CONFIG_ARM_EXYNOS_CPUIDLE */
> diff --git a/drivers/cpuidle/Kconfig.arm b/drivers/cpuidle/Kconfig.arm
> index 8e07c9419153..5eb86a4f74d9 100644
> --- a/drivers/cpuidle/Kconfig.arm
> +++ b/drivers/cpuidle/Kconfig.arm
> @@ -55,7 +55,8 @@ config ARM_AT91_CPUIDLE
>  config ARM_EXYNOS_CPUIDLE
>  	bool "Cpu Idle Driver for the Exynos processors"
>  	depends on ARCH_EXYNOS
> -	select ARCH_NEEDS_CPU_IDLE_COUPLED if SMP
> +	depends on SMP
> +	select ARCH_NEEDS_CPU_IDLE_COUPLED
>  	help
>  	  Select this to enable cpuidle for Exynos processors

How's about the patch below instead?  It builds fine for UP and SMP.
I will do more testing tomorrow (unfortunately it seems that something
else broke Origen4210 in -next).

From: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Subject: [PATCH] ARM: EXYNOS: cpuidle: Fix build breakage on !SMP

The Exynos cpuidle driver has coupled cpuidle built-in so it cannot be
built without SMP:

arch/arm/mach-exynos/pm.c: In function ‘exynos_cpu0_enter_aftr’:
arch/arm/mach-exynos/pm.c:246:4: error: implicit declaration of function ‘arch_send_wakeup_ipi_mask’ [-Werror=implicit-function-declaration]
arch/arm/mach-exynos/built-in.o: In function `exynos_pre_enter_aftr':
../arch/arm/mach-exynos/pm.c:300: undefined reference to `cpu_boot_reg_base'
arch/arm/mach-exynos/built-in.o: In function `exynos_cpu1_powerdown':
../arch/arm/mach-exynos/pm.c:282: undefined reference to `exynos_cpu_power_down'

Fix it by adding missing checks for SMP.

Reported-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
---
 arch/arm/mach-exynos/exynos.c    |    2 +-
 arch/arm/mach-exynos/pm.c        |    2 ++
 drivers/cpuidle/cpuidle-exynos.c |    3 ++-
 3 files changed, 5 insertions(+), 2 deletions(-)

Index: b/arch/arm/mach-exynos/exynos.c
===================================================================
--- a/arch/arm/mach-exynos/exynos.c	2015-02-04 18:30:23.555819717 +0100
+++ b/arch/arm/mach-exynos/exynos.c	2015-02-04 18:43:23.539807815 +0100
@@ -211,7 +211,7 @@ static void __init exynos_dt_machine_ini
 	if (!IS_ENABLED(CONFIG_SMP))
 		exynos_sysram_init();
 
-#ifdef CONFIG_ARM_EXYNOS_CPUIDLE
+#if defined(CONFIG_SMP) && defined(CONFIG_ARM_EXYNOS_CPUIDLE)
 	if (of_machine_is_compatible("samsung,exynos4210"))
 		exynos_cpuidle.dev.platform_data = &cpuidle_coupled_exynos_data;
 #endif
Index: b/arch/arm/mach-exynos/pm.c
===================================================================
--- a/arch/arm/mach-exynos/pm.c	2015-02-04 18:30:23.563819719 +0100
+++ b/arch/arm/mach-exynos/pm.c	2015-02-04 18:47:32.951804008 +0100
@@ -181,6 +181,7 @@ void exynos_enter_aftr(void)
 	cpu_pm_exit();
 }
 
+#if defined(CONFIG_SMP) && defined(CONFIG_ARM_EXYNOS_CPUIDLE)
 static atomic_t cpu1_wakeup = ATOMIC_INIT(0);
 
 static int exynos_cpu0_enter_aftr(void)
@@ -302,3 +303,4 @@ struct cpuidle_exynos_data cpuidle_coupl
 	.pre_enter_aftr		= exynos_pre_enter_aftr,
 	.post_enter_aftr		= exynos_post_enter_aftr,
 };
+#endif /* CONFIG_SMP && CONFIG_ARM_EXYNOS_CPUIDLE */
Index: b/drivers/cpuidle/cpuidle-exynos.c
===================================================================
--- a/drivers/cpuidle/cpuidle-exynos.c	2015-02-04 18:30:32.935819577 +0100
+++ b/drivers/cpuidle/cpuidle-exynos.c	2015-02-04 18:46:01.619805400 +0100
@@ -117,7 +117,8 @@ static int exynos_cpuidle_probe(struct p
 {
 	int ret;
 
-	if (of_machine_is_compatible("samsung,exynos4210")) {
+	if (IS_ENABLED(CONFIG_SMP) &&
+	    of_machine_is_compatible("samsung,exynos4210")) {
 		exynos_cpuidle_pdata = pdev->dev.platform_data;
 
 		ret = cpuidle_register(&exynos_coupled_idle_driver,