serial: Make full device search optional

Commit 608b0c4ad4 ("serial: Use next serial device if probing fails")
added code to search for more serial devices if the default one was not
probed correctly.

Unfortunately, that breaks omap3_evm. So while investigating why that is
the case, let's disable the full search for everyone but bcm283x where it
is needed.

Fixes: 608b0c4ad4 ("serial: Use next serial device if probing fails")
Reported-by: Derald D. Woods <woods.technical@gmail.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

arch/arm/Kconfig

@@ -550,6 +550,7 @@ config ARCH_BCM283X
 	select DM_GPIO
 	select OF_CONTROL
 	select PL01X_SERIAL
+	select SERIAL_SEARCH_ALL
 	imply FAT_WRITE
 
 config TARGET_VEXPRESS_CA15_TC2

drivers/serial/Kconfig

@@ -79,6 +79,18 @@ config SERIAL_RX_BUFFER_SIZE
 	help
 	  The size of the RX buffer (needs to be power of 2)
 
+config SERIAL_SEARCH_ALL
+	bool "Search for serial devices after default one failed"
+	depends on DM_SERIAL
+	help
+	  The serial subsystem only searches for a single serial device
+	  that was instantiated, but does not check whether it was probed
+	  correctly. With this option set, we make successful probing
+	  mandatory and search for fallback serial devices if the default
+	  device does not work.
+
+	  If unsure, say N.
+
 config SPL_DM_SERIAL
 	bool "Enable Driver Model for serial drivers in SPL"
 	depends on DM_SERIAL

drivers/serial/serial-uclass.c

@@ -74,7 +74,9 @@ static void serial_find_console_or_panic(void)
 {
 	const void *blob = gd->fdt_blob;
 	struct udevice *dev;
+#ifdef CONFIG_SERIAL_SEARCH_ALL
 	int ret;
+#endif
 
 	if (CONFIG_IS_ENABLED(OF_PLATDATA)) {
 		uclass_first_device(UCLASS_SERIAL, &dev);
@@ -113,6 +115,8 @@ static void serial_find_console_or_panic(void)
 #else
 #define INDEX 0
 #endif
+
+#ifdef CONFIG_SERIAL_SEARCH_ALL
 		if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
 		    !uclass_get_device(UCLASS_SERIAL, INDEX, &dev)) {
 			if (dev->flags & DM_FLAG_ACTIVATED) {
@@ -131,6 +135,15 @@ static void serial_find_console_or_panic(void)
 				return;
 			}
 		}
+#else
+		if (!uclass_get_device_by_seq(UCLASS_SERIAL, INDEX, &dev) ||
+		    !uclass_get_device(UCLASS_SERIAL, INDEX, &dev) ||
+		    (!uclass_first_device(UCLASS_SERIAL, &dev) && dev)) {
+			gd->cur_serial_dev = dev;
+			return;
+		}
+#endif
+
 #undef INDEX
 	}