diff options
Diffstat (limited to 'drivers/tty/serial/earlycon.c')
| -rw-r--r-- | drivers/tty/serial/earlycon.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c index 836cad222fcc..c3651540e1ba 100644 --- a/drivers/tty/serial/earlycon.c +++ b/drivers/tty/serial/earlycon.c @@ -21,6 +21,7 @@ #include <linux/sizes.h> #include <linux/of.h> #include <linux/of_fdt.h> +#include <linux/acpi.h> #ifdef CONFIG_FIX_EARLYCON_MEM #include <asm/fixmap.h> @@ -198,6 +199,14 @@ int __init setup_earlycon(char *buf) return -ENOENT; } +/* + * When CONFIG_ACPI_SPCR_TABLE is defined, "earlycon" without parameters in + * command line does not start DT earlycon immediately, instead it defers + * starting it until DT/ACPI decision is made. At that time if ACPI is enabled + * call parse_spcr(), else call early_init_dt_scan_chosen_stdout() + */ +bool earlycon_init_is_deferred __initdata; + /* early_param wrapper for setup_earlycon() */ static int __init param_setup_earlycon(char *buf) { @@ -207,8 +216,14 @@ static int __init param_setup_earlycon(char *buf) * Just 'earlycon' is a valid param for devicetree earlycons; * don't generate a warning from parse_early_params() in that case */ - if (!buf || !buf[0]) - return early_init_dt_scan_chosen_stdout(); + if (!buf || !buf[0]) { + if (IS_ENABLED(CONFIG_ACPI_SPCR_TABLE)) { + earlycon_init_is_deferred = true; + return 0; + } else { + return early_init_dt_scan_chosen_stdout(); + } + } err = setup_earlycon(buf); if (err == -ENOENT || err == -EALREADY) |