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Groups > linux.kernel > #1685194
| From | Palmer Dabbelt <palmer@dabbelt.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 08/17] tty: New RISC-V SBI console driver |
| Date | 2017-07-11 18:30 +0200 |
| Message-ID | <u26cV-4Ed-13@gated-at.bofh.it> (permalink) |
| References | <u1WQh-7b3-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Mon, 10 Jul 2017 23:21:07 PDT (-0700), mpe@ellerman.id.au wrote:
> Palmer Dabbelt <palmer@dabbelt.com> writes:
>>
> ...
>> +#ifdef CONFIG_EARLY_PRINTK
>> +static void sbi_console_write(struct console *co, const char *buf,
>> + unsigned int n)
>> +{
>> + int i;
>> +
>> + for (i = 0; i < n; ++i) {
>> + if (buf[i] == '\n')
>> + sbi_console_putchar('\r');
>> + sbi_console_putchar(buf[i]);
>> + }
>> +}
>> +
>> +static struct console early_console_dev __initdata = {
>> + .name = "early",
>> + .write = sbi_console_write,
>> + .flags = CON_PRINTBUFFER | CON_BOOT,
>
> AFAICS you could add CON_ANYTIME here, which would mean this console
> would print output before the CPU is online.
>
> I think it doesn't currently matter because you call parse_early_param()
> from setup_arch(), at which point the boot CPU has been marked online.
>
> But if this console can actually work earlier then you might be better
> off just registering it unconditionally very early.
That seems like a good idea. I'm not familiar with how all this works, but
from my understanding of this early_initcall() should be sufficient to make
this work? The only other driver that sets CON_ANYTIME and supports
EARLY_PRINTK is hvc_xen, but that installs a header to let init code register
the console directly. The early_initcall mechanism seems cleaner if it does
the right thing.
How does this look?
diff --git a/drivers/tty/hvc/hvc_sbi.c b/drivers/tty/hvc/hvc_sbi.c
index 98114cbd85f1..534d6b75a2c6 100644
--- a/drivers/tty/hvc/hvc_sbi.c
+++ b/drivers/tty/hvc/hvc_sbi.c
@@ -87,11 +87,11 @@ static void sbi_console_write(struct console *co, const char *buf,
static struct console early_console_dev __initdata = {
.name = "early",
.write = sbi_console_write,
- .flags = CON_PRINTBUFFER | CON_BOOT,
+ .flags = CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME,
.index = -1
};
-static int __init setup_early_printk(char *str)
+static int __init setup_early_printk(void)
{
if (early_console == NULL) {
early_console = &early_console_dev;
@@ -99,5 +99,5 @@ static int __init setup_early_printk(char *str)
}
return 0;
}
-early_param("earlyprintk", setup_early_printk);
+early_initcall(setup_early_printk);
#endif
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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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