[PATCH v2 5/5] ARM: use early console instead of early debug in allmodconfig kernels

Russell King - ARM Linux
2014-10-28T14:05:36Z

On Tue, Oct 28, 2014 at 09:31:35PM +0800, Xia Kaixu wrote:
> The early debug could break something when booting 'allmodconfig'
> kernels. So we use early console instead of early debug.
>
> The early console didn't work yet on OMAP4460 because of missing
> earlycon support and I am working on that.

No. bloody. way.

> @@ -78,7 +78,7 @@ config DEBUG_USER
> # These options are only for real kernel hackers who want to get their hands dirty.
> config DEBUG_LL
> bool "Kernel low-level debugging functions (read help!)"
> - depends on DEBUG_KERNEL
> + depends on DEBUG_KERNEL && !ARCH_MULTIPLATFORM_STRICT

Firstly, this is well advertised that it can only be applied to a single
configuration. So I don't think we need this dependency here. Even if
you want to build a strict multiplatform kernel, it should still be
possible to enable this for a specific platform.

It's a developer option, one which requires the developer to engage their
brain before using.

> @@ -1297,6 +1297,29 @@ config EARLY_PRINTK
> kernel low-level debugging functions. Add earlyprintk to your
> kernel parameters to enable this console.
>
> +config FORCE_EARLY_CONSOLE
> + bool "Enable all early console drivers"
> + depends on DEBUG_KERNEL && ARCH_MULTIPLATFORM_STRICT
> + select TTY
> + select SERIAL_8250
> + select SERIAL_8250_CONSOLE
> + select SERIAL_AMBA_PL011
> + select SERIAL_AMBA_PL011_CONSOLE
> + select SERIAL_EARLYCON_ARM_SEMIHOST
> + select SERIAL_MSM
> + select SERIAL_MSM_CONSOLE
> + select SERIAL_XILINX_PS_UART
> + select SERIAL_XILINX_PS_UART_CONSOLE

Not only will this be a for-ever expanding list, but it'll also continually
suffer from various problems with dependencies. I absolutely *HATE* the
idea of selecting user visible options like this.

--
FTTC broadband for 0.8mile line: currently at 9.5Mbps down 400kbps up
according to speedtest.net.