[PATCH] hvc_vio: Do not override preferred console set by kernel parameter

[Ben Hutchings]

The original version of this was done by Bastian Blank, who wrote:

> The problem is the following:
> - Architecture specific code sets preferred console to something bogus.
> - Command line handling tries to set preferred console but is overruled
>   by the old setting.
> 
> The udbg0 console is a boot console and independant.

References: http://bugs.debian.org/492703
Signed-off-by: Ben Hutchings <ben at decadent.org.uk>
---
We've been carrying this in Debian for 5 years now, so it's about time
it got reviewed.

I'm not convinced strstr() is the right way to check the command line
(what if there's also a 'netconsole='?).

Ben.

--- a/drivers/tty/hvc/hvc_vio.c
+++ b/drivers/tty/hvc/hvc_vio.c
@@ -48,6 +48,7 @@
 #include <asm/prom.h>
 #include <asm/hvsi.h>
 #include <asm/udbg.h>
+#include <asm/machdep.h>
 
 #include "hvc_console.h"
 
@@ -440,7 +441,9 @@
 	if (hvterm_priv0.proto == HV_PROTOCOL_HVSI)
 		goto out;
 #endif
-	add_preferred_console("hvc", 0, NULL);
+	/* Check whether the user has requested a different console. */
+	if (!strstr(cmd_line, "console="))
+		add_preferred_console("hvc", 0, NULL);
 	hvc_instantiate(0, 0, ops);
 out:
 	of_node_put(stdout_node);

-- 
Ben Hutchings
The most exhausting thing in life is being insincere. - Anne Morrow Lindberg
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