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SubjectRe: [PATCH 1/3] ARM: EXYNOS: uncompress - print debug messages if DEBUG_LL is defined
On Fri, May 31, 2013 at 05:19:02PM +0530, Tushar Behera wrote:
> Printing low-level debug messages make an assumption that the specified
> UART port has been preconfigured by the bootloader. Incorrectly
> specified UART port results in system getting stalled while printing the
> message "Uncompressing Linux... done, booting the kernel"
>
> This UART port number is specified through S3C_LOWLEVEL_UART_PORT. Since
> the UART port might different for different board, it is not possible to
> specify it correctly for every board that use a common defconfig file.
>
> Calling this print subroutine only when DEBUG_LL fixes the problem. By
> disabling DEBUG_LL in default config file, we would be able to boot
> multiple boards with different default UART ports.
>
> With this current approach, we miss the print "Uncompressing Linux...
> done, booting the kernel." when DEBUG_LL is not defined.
>
> Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
> ---
> arch/arm/mach-exynos/include/mach/uncompress.h | 11 ++++++++---
> arch/arm/plat-samsung/include/plat/uncompress.h | 10 +++++++++-
> 2 files changed, 17 insertions(+), 4 deletions(-)
>
> diff --git a/arch/arm/mach-exynos/include/mach/uncompress.h b/arch/arm/mach-exynos/include/mach/uncompress.h
> index 2979995..730f69f 100644
> --- a/arch/arm/mach-exynos/include/mach/uncompress.h
> +++ b/arch/arm/mach-exynos/include/mach/uncompress.h
> @@ -37,11 +37,16 @@ static void arch_detect_cpu(void)
> chip_id >>= 20;
> chip_id &= 0xf;
>
> +#ifdef CONFIG_DEBUG_LL
> if (chip_id == 0x5)
> - uart_base = (volatile u8 *)EXYNOS5_PA_UART + (S3C_UART_OFFSET * CONFIG_S3C_LOWLEVEL_UART_PORT);
> + uart_base = (volatile u8 *)EXYNOS5_PA_UART +
> + (S3C_UART_OFFSET * CONFIG_S3C_LOWLEVEL_UART_PORT);
> else
> - uart_base = (volatile u8 *)EXYNOS4_PA_UART + (S3C_UART_OFFSET * CONFIG_S3C_LOWLEVEL_UART_PORT);
> -
> + uart_base = (volatile u8 *)EXYNOS4_PA_UART +
> + (S3C_UART_OFFSET * CONFIG_S3C_LOWLEVEL_UART_PORT);
> +#else
> + uart_base = NULL;
> +#endif

You can do:

if (!config_enabled(CONFIG_DEBUG_LL))
return;

Since uart_base will be set to 0 by being in BSS anyway.


-Olof


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