From mboxrd@z Thu Jan  1 00:00:00 1970
From: jonathanh@nvidia.com (Jon Hunter)
Date: Mon, 29 Feb 2016 10:46:01 +0000
Subject: [PATCH] ARM64: Don't set the default console to ttyAMA0
In-Reply-To: <1455727422-10733-1-git-send-email-jonathanh@nvidia.com>
References: <1455727422-10733-1-git-send-email-jonathanh@nvidia.com>
Message-ID: <56D42169.70804@nvidia.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Hi Will, Catalin,

Any feedback on this?

Cheers
Jon

On 17/02/16 16:43, Jon Hunter wrote:
> When booting Tegra210 with a minimal rootfs it may not be necessary to
> specify any boot parameters via the kernel command line as information
> for console is described via the "stdout-path" node the device-tree
> blob. However, when there are no boot parameter specified, no output is
> seen on the console in the case of Tegra210 and this is because the
> default command line in the ARM64 defconfig specifies the console as
> ttyAMA0 which takes precedence over the "stdout-path" node from
> device-tree.
> 
> ttyAMAx is used for AMBA PL011 serial ports, but not all ARM64 platforms
> use this serial driver. Therefore, remove the default command line
> entry from the ARM64 defconfig to ensure that ttyAMA0 does not get set
> as the default console if no kernel command line is specified.
> 
> Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
> ---
>  arch/arm64/configs/defconfig | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
> index d21631760ec7..caecb66188be 100644
> --- a/arch/arm64/configs/defconfig
> +++ b/arch/arm64/configs/defconfig
> @@ -64,7 +64,6 @@ CONFIG_KSM=y
>  CONFIG_TRANSPARENT_HUGEPAGE=y
>  CONFIG_CMA=y
>  CONFIG_XEN=y
> -CONFIG_CMDLINE="console=ttyAMA0"
>  # CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set
>  CONFIG_COMPAT=y
>  CONFIG_CPU_IDLE=y
>