serial: sh-sci: Limit early console to one device.

Presently the early console setup will be invoked for every device handed
off to he earlyprintk command line argument. In practice we can only
handle one, so this adds a sanity check to prevent clobbering the
existing active console.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

drivers/serial/sh-sci.c

@@ -1870,13 +1870,40 @@ static int __init sci_console_init(void)
 console_initcall(sci_console_init);
 
 static struct sci_port early_serial_port;
+
 static struct console early_serial_console = {
 	.name           = "early_ttySC",
 	.write          = serial_console_write,
 	.flags          = CON_PRINTBUFFER,
 };
+
 static char early_serial_buf[32];
 
+static int __devinit sci_probe_earlyprintk(struct platform_device *pdev)
+{
+	struct plat_sci_port *cfg = pdev->dev.platform_data;
+
+	if (early_serial_console.data)
+		return -EEXIST;
+
+	early_serial_console.index = pdev->id;
+	early_serial_console.data = &early_serial_port.port;
+
+	sci_init_single(NULL, &early_serial_port, pdev->id, cfg);
+
+	serial_console_setup(&early_serial_console, early_serial_buf);
+
+	if (!strstr(early_serial_buf, "keep"))
+		early_serial_console.flags |= CON_BOOT;
+
+	register_console(&early_serial_console);
+	return 0;
+}
+#else
+static inline int __devinit sci_probe_earlyprintk(struct platform_device *pdev)
+{
+	return -EINVAL;
+}
 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE */
 
 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE)
@@ -1937,34 +1964,19 @@ static int __devinit sci_probe_single(struct platform_device *dev,
 	return uart_add_one_port(&sci_uart_driver, &sciport->port);
 }
 
-/*
- * Register a set of serial devices attached to a platform device.  The
- * list is terminated with a zero flags entry, which means we expect
- * all entries to have at least UPF_BOOT_AUTOCONF set. Platforms that need
- * remapping (such as sh64) should also set UPF_IOREMAP.
- */
 static int __devinit sci_probe(struct platform_device *dev)
 {
 	struct plat_sci_port *p = dev->dev.platform_data;
 	struct sci_port *sp = &sci_ports[dev->id];
-	int ret = -EINVAL;
-
-#ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
-	if (is_early_platform_device(dev)) {
-		early_serial_console.index = dev->id;
-		early_serial_console.data = &early_serial_port.port;
-
-		sci_init_single(NULL, &early_serial_port, dev->id, p);
-
-		serial_console_setup(&early_serial_console, early_serial_buf);
-
-		if (!strstr(early_serial_buf, "keep"))
-			early_serial_console.flags |= CON_BOOT;
+	int ret;
 
-		register_console(&early_serial_console);
-		return 0;
-	}
-#endif
+	/*
+	 * If we've come here via earlyprintk initialization, head off to
+	 * the special early probe. We don't have sufficient device state
+	 * to make it beyond this yet.
+	 */
+	if (is_early_platform_device(dev))
+		return sci_probe_earlyprintk(dev);
 
 	platform_set_drvdata(dev, sp);