On 12/07/2017 01:46 PM, Timur Tabi wrote:

On Thu, Dec 7, 2017 at 11:29 AM, Prarit Bhargava [off-list ref] wrote:

quoted

-int __init acpi_parse_spcr(bool earlycon)
+int __init acpi_parse_spcr(bool earlycon, bool enable_console)
 {
        static char opts[ACPI_SPCR_OPTS_SIZE];
        static char uart[ACPI_SPCR_BUF_SIZE];

@@ -113,7 +113,8 @@ int __init acpi_parse_spcr(bool earlycon)
        if (earlycon)
                setup_earlycon(opts);

-       err = add_preferred_console(uart, 0, opts + strlen(uart) + 1);
+       if (enable_console)
+               err = add_preferred_console(uart, 0, opts + strlen(uart) + 1);

So if earlycon==true but enable_console==false, then you parse SPCR
and use it for the early console, but not the primary console?  I'm
not sure what that gives you.

On arm64 the original SPCR code provides both early and primary consoles (as
you've pointed out).  IOW, if SPRC exists on arm64 a console will be
initialized.  That is still the case after my change.

The expected behaviour on x86 is that unless someone specifies 'earlycon' or
'console=' that no console should be initialized.  There are users (some IOT
boxes, etc.) that do NOT want a console.

The above code keeps the existing x86 behaviour.

P.