x86, setup: Fix earlyprintk=serial,0x3f8,115200

earlyprintk can take and I/O port, so we need to handle this case in
the setup code too, otherwise 0x3f8 will be treated as a baud rate.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4C7B05A6.4010801@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

diff --git a/arch/x86/boot/early_serial_console.c b/arch/x86/boot/early_serial_console.c
index 407a8e2..5df2869 100644 (file)
--- a/arch/x86/boot/early_serial_console.c
+++ b/arch/x86/boot/early_serial_console.c
@@ -58,7 +58,19 @@ static void parse_earlyprintk(void)
                if (arg[pos] == ',')
                        pos++;
 
-               if (!strncmp(arg + pos, "ttyS", 4)) {
+               /*
+                * make sure we have
+                *      "serial,0x3f8,115200"
+                *      "serial,ttyS0,115200"
+                *      "ttyS0,115200"
+                */
+               if (pos == 7 && !strncmp(arg + pos, "0x", 2)) {
+                       port = simple_strtoull(arg + pos, &e, 16);
+                       if (port == 0 || arg + pos == e)
+                               port = DEFAULT_SERIAL_PORT;
+                       else
+                               pos = e - arg;
+               } else if (!strncmp(arg + pos, "ttyS", 4)) {
                        static const int bases[] = { 0x3f8, 0x2f8 };
                        int idx = 0;