serial: kgdboc: Allow earlycon initialization to be deferred (a4912303) · Commits · 戴 / test

drivers/tty/serial/kgdboc.c

+38 −1

Original line number	Diff line number	Diff line
		@@ -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) {
		/*
		* 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);

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