[PATCH] x86: Fix earlyprintk ttyS2/3

[Daniel J Blueman <daniel@numascale.com>]

Quite a few platforms use ttyS2 for their serial-over-LAN, so fix early
printk support for ttyS2 and 3, avoiding the need to hard-code the IO port.

Signed-off-by: Daniel J Blueman <daniel@numascale.com>
---
 arch/x86/boot/early_serial_console.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/x86/boot/early_serial_console.c b/arch/x86/boot/early_serial_console.c
index 5df2869..4f4c2e6 100644
--- a/arch/x86/boot/early_serial_console.c
+++ b/arch/x86/boot/early_serial_console.c
@@ -71,15 +71,16 @@ static void parse_earlyprintk(void)
 			else
 				pos = e - arg;
 		} else if (!strncmp(arg + pos, "ttyS", 4)) {
-			static const int bases[] = { 0x3f8, 0x2f8 };
-			int idx = 0;
+			static const int bases[] = {0x3f8, 0x2f8, 0x3e8, 0x2e8};
+			unsigned idx = 0;
 
 			if (!strncmp(arg + pos, "ttyS", 4))
 				pos += 4;
 
-			if (arg[pos++] == '1')
-				idx = 1;
+			if ((arg[pos] - '0') < (sizeof(bases) / sizeof(bases[0])))
+				idx = arg[pos] - '0';
 
+			pos++;
 			port = bases[idx];
 		}
 
-- 
2.1.0