MIPS: ralink: Remove ralink_halt()

commit 891731f6a5dbe508d12443175a7e166a2fba616a upstream.

ralink_halt() does nothing that machine_halt() doesn't already do, so it
adds no value.

It actually causes incorrect behaviour due to the "unreachable()" at the
end. This tells the compiler that the end of the function will never be
reached, which isn't true. The compiler responds by not adding a
'return' instruction, so control simply moves on to whatever bytes come
afterwards in memory. In my tested, that was the ralink_restart()
function. This means that an attempt to 'halt' the machine would
actually cause a reboot.

So remove ralink_halt() so that a 'halt' really does halt.

Fixes: c06e836ada59 ("MIPS: ralink: adds reset code")
Signed-off-by: NeilBrown <neil@brown.name>
Cc: John Crispin <john@phrozen.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.9+
Patchwork: https://patchwork.linux-mips.org/patch/18851/
Signed-off-by: James Hogan <jhogan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/mips/ralink/reset.c b/arch/mips/ralink/reset.c
index 64543d66e76b50ccace33bf942e0b3c61c7e7fa4..e9531fea23a297adf2aac05d68ffd04dede6e0d4 100644 (file)
--- a/arch/mips/ralink/reset.c
+++ b/arch/mips/ralink/reset.c
@@ -96,16 +96,9 @@ static void ralink_restart(char *command)
        unreachable();
 }
 
-static void ralink_halt(void)
-{
-       local_irq_disable();
-       unreachable();
-}
-
 static int __init mips_reboot_setup(void)
 {
        _machine_restart = ralink_restart;
-       _machine_halt = ralink_halt;
 
        return 0;
 }