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Re: [PATCH 17/17] RISC-V: Build Infastructure

From Palmer Dabbelt <palmer@dabbelt.com>
Newsgroups linux.kernel
Subject Re: [PATCH 17/17] RISC-V: Build Infastructure
Date 2017-07-11 18:30 +0200
Message-ID <u26cV-4Ed-15@gated-at.bofh.it> (permalink)
References <u1WZX-7e0-15@gated-at.bofh.it>
Organization linux.* mail to news gateway

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On Mon, 10 Jul 2017 23:31:18 PDT (-0700), mpe@ellerman.id.au wrote:
> Palmer Dabbelt <palmer@dabbelt.com> writes:
>
>> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
>> new file mode 100644
>> index 000000000000..366f5f2cf106
>> --- /dev/null
>> +++ b/arch/riscv/Kconfig
>> @@ -0,0 +1,294 @@
> ...
>> +
>> +config EARLY_PRINTK
>> +	bool "Early printk"
>> +	default n
>> +	help
>> +	  This option enables special console drivers which allow the kernel
>> +	  to print messages very early in the bootup process.
>> +
>> +	  This is useful for kernel debugging when your machine crashes very
>> +	  early before the console code is initialized. For normal operation
>> +	  it is not recommended because it looks ugly and doesn't cooperate
>> +	  with klogd/syslogd or the X server. You should normally N here,
>> +	  unless you want to debug such a crash.
>
> Looks like you copied this text from x86? I think the comment about it
> being ugly refers to the VGA early console which you don't have, so
> that's not really accurate.
>
> And the part about it not cooperating with klogs/syslogd is true, early
> printk output doesn't go to syslog. But if you turn EARLY_PRINTK off
> then early printk output goes nowhere at all:
>
> #ifdef CONFIG_EARLY_PRINTK
> extern asmlinkage __printf(1, 2)
> void early_printk(const char *fmt, ...);
> #else
> static inline __printf(1, 2) __cold
> void early_printk(const char *s, ...) { }
> #endif
>
>
> So if you have a functional early console (which I think you do) then
> you might be better off just making this def_bool y.

I think that's best.  The SBI's EARLY_PRINTK support is quite clean, so I don't
see any reason to disable it.  How does this look?

  diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
  index 366f5f2cf106..cc274bbc29a7 100644
  --- a/arch/riscv/Kconfig
  +++ b/arch/riscv/Kconfig
  @@ -268,18 +268,7 @@ config CMDLINE_OVERRIDE
            If you don't know what to do here, say N.

   config EARLY_PRINTK
  -       bool "Early printk"
  -       default n
  -       help
  -         This option enables special console drivers which allow the kernel
  -         to print messages very early in the bootup process.
  -
  -         This is useful for kernel debugging when your machine crashes very
  -         early before the console code is initialized. For normal operation
  -         it is not recommended because it looks ugly and doesn't cooperate
  -         with klogd/syslogd or the X server. You should normally N here,
  -         unless you want to debug such a crash.
  -
  +       def_bool y

   source "lib/Kconfig.debug"

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Thread

RISC-V Linux Port v5 Palmer Dabbelt <palmer@dabbelt.com> - 2017-07-11 04:00 +0200
  [PATCH 17/17] RISC-V: Build Infastructure Palmer Dabbelt <palmer@dabbelt.com> - 2017-07-11 04:00 +0200
    Re: [PATCH 17/17] RISC-V: Build Infastructure Michael Ellerman <mpe@ellerman.id.au> - 2017-07-11 08:40 +0200
      Re: [PATCH 17/17] RISC-V: Build Infastructure Palmer Dabbelt <palmer@dabbelt.com> - 2017-07-11 18:30 +0200
        Re: [PATCH 17/17] RISC-V: Build Infastructure Michael Ellerman <mpe@ellerman.id.au> - 2017-07-12 12:50 +0200
  [PATCH 06/17] irqchip: RISC-V Local Interrupt Controller Driver Palmer Dabbelt <palmer@dabbelt.com> - 2017-07-11 04:00 +0200
  [PATCH 07/17] irqchip: New RISC-V PLIC Driver Palmer Dabbelt <palmer@dabbelt.com> - 2017-07-11 04:00 +0200
  [PATCH 02/17] pci: Add a generic, weakly-linked pcibios_align_resource Palmer Dabbelt <palmer@dabbelt.com> - 2017-07-11 04:00 +0200
  [PATCH 08/17] tty: New RISC-V SBI console driver Palmer Dabbelt <palmer@dabbelt.com> - 2017-07-11 04:00 +0200
    Re: [PATCH 08/17] tty: New RISC-V SBI console driver Michael Ellerman <mpe@ellerman.id.au> - 2017-07-11 08:30 +0200
      Re: [PATCH 08/17] tty: New RISC-V SBI console driver Palmer Dabbelt <palmer@dabbelt.com> - 2017-07-11 18:30 +0200
        Re: [PATCH 08/17] tty: New RISC-V SBI console driver Michael Ellerman <mpe@ellerman.id.au> - 2017-07-12 13:10 +0200
          Re: [PATCH 08/17] tty: New RISC-V SBI console driver Palmer Dabbelt <palmer@dabbelt.com> - 2017-07-12 18:30 +0200
            Re: [PATCH 08/17] tty: New RISC-V SBI console driver Michael Ellerman <mpe@ellerman.id.au> - 2017-07-13 14:10 +0200
              Re: [PATCH 08/17] tty: New RISC-V SBI console driver James Hogan <james.hogan@imgtec.com> - 2017-07-13 14:40 +0200
                Re: [PATCH 08/17] tty: New RISC-V SBI console driver Palmer Dabbelt <palmer@dabbelt.com> - 2017-07-14 00:00 +0200
                Re: [PATCH 08/17] tty: New RISC-V SBI console driver Michael Ellerman <mpe@ellerman.id.au> - 2017-07-14 07:10 +0200
  [PATCH 12/17] RISC-V: ELF and module implementation Palmer Dabbelt <palmer@dabbelt.com> - 2017-07-11 04:00 +0200
  [PATCH 15/17] RISC-V: Paging and MMU Palmer Dabbelt <palmer@dabbelt.com> - 2017-07-11 04:00 +0200
  [PATCH 04/17] MAINTAINERS: Add RISC-V Palmer Dabbelt <palmer@dabbelt.com> - 2017-07-11 04:00 +0200
  [PATCH 05/17] clocksource: New RISC-V SBI timer driver Palmer Dabbelt <palmer@dabbelt.com> - 2017-07-11 04:00 +0200
  [PATCH 03/17] pci: Add a generic, weakly-linked pcibios_fixup_bus Palmer Dabbelt <palmer@dabbelt.com> - 2017-07-11 04:00 +0200
    Re: [PATCH 03/17] pci: Add a generic, weakly-linked pcibios_fixup_bus "Luis R. Rodriguez" <mcgrof@kernel.org> - 2017-07-11 21:00 +0200
  [PATCH 01/17] lib: Add shared copies of some GCC library routines Palmer Dabbelt <palmer@dabbelt.com> - 2017-07-11 04:00 +0200
    Re: [PATCH 01/17] lib: Add shared copies of some GCC library routines Randy Dunlap <rdunlap@infradead.org> - 2017-07-11 04:10 +0200
    Re: [PATCH 01/17] lib: Add shared copies of some GCC library  routines Stephen Rothwell <sfr@canb.auug.org.au> - 2017-07-11 04:10 +0200
  [PATCH 14/17] RISC-V: Device, timer, IRQs, and the SBI Palmer Dabbelt <palmer@dabbelt.com> - 2017-07-11 04:00 +0200
  Re: [PATCH 16/17] RISC-V: User-facing API Christoph Hellwig <hch@infradead.org> - 2017-07-11 15:50 +0200
    Re: [PATCH 16/17] RISC-V: User-facing API James Hogan <james.hogan@imgtec.com> - 2017-07-11 16:10 +0200
      Re: [patches] Re: [PATCH 16/17] RISC-V: User-facing API Palmer Dabbelt <palmer@dabbelt.com> - 2017-07-11 19:30 +0200
  Re: RISC-V Linux Port v5 "Luis R. Rodriguez" <mcgrof@kernel.org> - 2017-07-11 20:40 +0200
    Re: RISC-V Linux Port v5 Palmer Dabbelt <palmer@dabbelt.com> - 2017-07-11 22:00 +0200

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