diff options
| -rw-r--r-- | drivers/tty/serial/kgdboc.c | 39 |
1 files changed, 38 insertions, 1 deletions
diff --git a/drivers/tty/serial/kgdboc.c b/drivers/tty/serial/kgdboc.c index fa6f7a3e73b9..41396982e9e0 100644 --- a/drivers/tty/serial/kgdboc.c +++ b/drivers/tty/serial/kgdboc.c @@ -514,6 +514,10 @@ static struct kgdb_io kgdboc_earlycon_io_ops = { .is_console = true, }; +#define MAX_CONSOLE_NAME_LEN (sizeof((struct console *) 0)->name) +static char kgdboc_earlycon_param[MAX_CONSOLE_NAME_LEN] __initdata; +static bool kgdboc_earlycon_late_enable __initdata; + static int __init kgdboc_earlycon_init(char *opt) { struct console *con; @@ -533,7 +537,23 @@ static int __init kgdboc_earlycon_init(char *opt) } if (!con) { - pr_info("Couldn't find kgdb earlycon\n"); + /* + * Both earlycon and kgdboc_earlycon are initialized during * early parameter parsing. We cannot guarantee earlycon gets + * in first and, in any case, on ACPI systems earlycon may + * defer its own initialization (usually to somewhere within + * setup_arch() ). To cope with either of these situations + * we can defer our own initialization to a little later in + * the boot. + */ + if (!kgdboc_earlycon_late_enable) { + pr_info("No suitable earlycon yet, will try later\n"); + if (opt) + strscpy(kgdboc_earlycon_param, opt, + sizeof(kgdboc_earlycon_param)); + kgdboc_earlycon_late_enable = true; + } else { + pr_info("Couldn't find kgdb earlycon\n"); + } goto unlock; } @@ -556,6 +576,23 @@ unlock: } early_param("kgdboc_earlycon", kgdboc_earlycon_init); + +/* + * This is only intended for the late adoption of an early console. + * + * It is not a reliable way to adopt regular consoles because we can not + * control what order console initcalls are made and, in any case, many + * regular consoles are registered much later in the boot process than + * the console initcalls! + */ +static int __init kgdboc_earlycon_late_init(void) +{ + if (kgdboc_earlycon_late_enable) + kgdboc_earlycon_init(kgdboc_earlycon_param); + return 0; +} +console_initcall(kgdboc_earlycon_late_init); + #endif /* IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE) */ module_init(init_kgdboc); |