[PATCH 02/13] ARM: SAMSUNG: allow the configuration of KERNEL HZ in plat-samsung

[PATCH 02/13] ARM: SAMSUNG: allow the configuration of KERNEL HZ in plat-samsung

[Kukjin Kim]

Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
---
 arch/arm/Kconfig              |    4 ++--
 arch/arm/plat-samsung/Kconfig |    7 +++++++
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 24626b0..f9d7c47 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1590,8 +1590,8 @@ source kernel/Kconfig.preempt
 
 config HZ
 	int
-	default 200 if ARCH_EBSA110 || ARCH_S3C2410 || ARCH_S5P64X0 || \
-		ARCH_S5PV210 || ARCH_EXYNOS4
+	default 200 if ARCH_EBSA110
+	default SAMSUNG_TIMER_HZ if PLAT_SAMSUNG
 	default OMAP_32K_TIMER_HZ if ARCH_OMAP && OMAP_32K_TIMER
 	default AT91_TIMER_HZ if ARCH_AT91
 	default SHMOBILE_TIMER_HZ if ARCH_SHMOBILE
diff --git a/arch/arm/plat-samsung/Kconfig b/arch/arm/plat-samsung/Kconfig
index 6a2abe6..0a23b52 100644
--- a/arch/arm/plat-samsung/Kconfig
+++ b/arch/arm/plat-samsung/Kconfig
@@ -50,6 +50,13 @@ config S3C_LOWLEVEL_UART_PORT
 	  this configuration should be between zero and two. The port
 	  must have been initialised by the boot-loader before use.
 
+config SAMSUNG_TIMER_HZ
+	int "Kernel HZ for Samsung Platform"
+	range 32 1024
+	default "200"
+	help
+	  Allows the configuration of the timer frequency for Samsung SoCs.
+
 # clock options
 
 config SAMSUNG_CLKSRC
-- 
1.7.1

[PATCH 02/13] ARM: SAMSUNG: allow the configuration of KERNEL HZ in plat-samsung

[Kukjin Kim]

Kukjin Kim wrote:
> 
> 
Please kindly ignore the patch number[02/13] in subject.

Thanks.

Best regards,
Kgene.
--
Kukjin Kim <kgene.kim@samsung.com>, Senior Engineer,
SW Solution Development Team, Samsung Electronics Co., Ltd.

> Cc: Russell King <rmk+kernel@arm.linux.org.uk>
> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
> ---
>  arch/arm/Kconfig              |    4 ++--
>  arch/arm/plat-samsung/Kconfig |    7 +++++++
>  2 files changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 24626b0..f9d7c47 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -1590,8 +1590,8 @@ source kernel/Kconfig.preempt
> 
>  config HZ
>  	int
> -	default 200 if ARCH_EBSA110 || ARCH_S3C2410 || ARCH_S5P64X0 || \
> -		ARCH_S5PV210 || ARCH_EXYNOS4
> +	default 200 if ARCH_EBSA110
> +	default SAMSUNG_TIMER_HZ if PLAT_SAMSUNG
>  	default OMAP_32K_TIMER_HZ if ARCH_OMAP && OMAP_32K_TIMER
>  	default AT91_TIMER_HZ if ARCH_AT91
>  	default SHMOBILE_TIMER_HZ if ARCH_SHMOBILE
> diff --git a/arch/arm/plat-samsung/Kconfig b/arch/arm/plat-samsung/Kconfig
> index 6a2abe6..0a23b52 100644
> --- a/arch/arm/plat-samsung/Kconfig
> +++ b/arch/arm/plat-samsung/Kconfig
> @@ -50,6 +50,13 @@ config S3C_LOWLEVEL_UART_PORT
>  	  this configuration should be between zero and two. The port
>  	  must have been initialised by the boot-loader before use.
> 
> +config SAMSUNG_TIMER_HZ
> +	int "Kernel HZ for Samsung Platform"
> +	range 32 1024
> +	default "200"
> +	help
> +	  Allows the configuration of the timer frequency for Samsung SoCs.
> +
>  # clock options
> 
>  config SAMSUNG_CLKSRC
> --
> 1.7.1

[PATCH 02/13] ARM: SAMSUNG: allow the configuration of KERNEL HZ in plat-samsung

[Russell King - ARM Linux]

On Fri, Jan 27, 2012 at 10:44:20AM +0900, Kukjin Kim wrote:
> 
> Cc: Russell King <rmk+kernel@arm.linux.org.uk>
> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

This patch really needs some kind of explanation.  It's far from obvious
from the casual reader why moving from a fixed value of 200Hz for the
kernel tick rate to a range from 32 to 1024 would be legal.

If 100Hz was possible before, and that's the architecture default, why
was 200Hz chosen instead?

And is 99Hz and 101Hz allowable?