Messages in this thread | | | Date | Thu, 16 Aug 2018 17:09:48 +0200 | From | Greg Kroah-Hartman <> | Subject | Re: [PATCH] console: Add console=auto option |
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On Thu, Aug 16, 2018 at 10:10:55AM -0400, Prarit Bhargava wrote: > ACPI may contain an SPCR table that defines a default system console. > On ARM if the table is present then the SPCR console is enabled by default. > On x86 the SPCR console is used if 'earlycon' (no parameters) is > specified as a kernel parameter and is used only as the early console. > To use the SPCR data as a console a user must boot with 'earlycon', > grep logs & specify a console= kernel parameter, and then reboot again. > > Add 'console=auto' that enables a firmware or hardware console, and on > x86 enable the SPCR console if 'console=auto' is specified. > > Tested on systems with and without an ACPI SPCR. The following kernel > parameters were also tested: > > console=ttyS0,115200 works > earlycon works (early console only) > console=auto works (full console as expected) > no console or earlycon arguments works (no output as expected) > > Signed-off-by: Prarit Bhargava <prarit@redhat.com> > Cc: Mark Salter <msalter@redhat.com> > Cc: Al Stone <ahs3@redhat.com> > Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> > Cc: Len Brown <len.brown@intel.com> > Cc: Pavel Machek <pavel@ucw.cz> > Cc: x86@kernel.org > Cc: Petr Mladek <pmladek@suse.com> > Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> > Cc: Steven Rostedt <rostedt@goodmis.org> > Cc: Kees Cook <keescook@chromium.org> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: linux-pm@vger.kernel.org > --- > Documentation/admin-guide/kernel-parameters.txt | 1 + > arch/x86/kernel/acpi/boot.c | 5 +++++ > include/linux/console.h | 1 + > kernel/printk/printk.c | 10 ++++++++++ > 4 files changed, 17 insertions(+) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index a32f2a126791..dd057224f33b 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -635,6 +635,7 @@ > > hvc<n> Use the hypervisor console device <n>. This is for > both Xen and PowerPC hypervisors. > + auto [X86] Enable ACPI SPCR console > > If the device connected to the port is not a TTY but a braille > device, prepend "brl," before the device type, for instance > diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c > index 3b20607d581b..fb2616ba3b21 100644 > --- a/arch/x86/kernel/acpi/boot.c > +++ b/arch/x86/kernel/acpi/boot.c > @@ -1771,3 +1771,8 @@ void __init arch_reserve_mem_area(acpi_physical_address addr, size_t size) > e820__range_add(addr, size, E820_TYPE_ACPI); > e820__update_table_print(); > } > + > +void __init arch_console_setup(void) > +{ > + acpi_parse_spcr(false, true); > +}
<snip>
> +int arch_console_setup(void);
Function does not match its prototype :(
How did you build this successfully?
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