powerpc/kdump: Fix timeout in crash_kexec_wait_realmode

The existing code it pretty ugly.  How about we clean it up even more
like this?

From: Anton Blanchard <anton@samba.org>

We check for timeout expiry in the outer loop, but we also need to
check it in the inner loop or we can lock up forever waiting for a
CPU to hit real mode.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Cc: <stable@kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 1 insertions, 5 deletions

diff --git a/arch/powerpc/kernel/crash.c b/arch/powerpc/kernel/crash.c
index 4e6ee944495..cc6a9d5d69a 100644
--- a/arch/powerpc/kernel/crash.c
+++ b/arch/powerpc/kernel/crash.c
@@ -242,12 +242,8 @@ static void crash_kexec_wait_realmode(int cpu)
 
                 while (paca[i].kexec_state < KEXEC_STATE_REAL_MODE) {
                         barrier();
-                        if (!cpu_possible(i)) {
+                        if (!cpu_possible(i) || !cpu_online(i) || (msecs <= 0))
                                 break;
-                        }
-                        if (!cpu_online(i)) {
-                                break;
-                        }
                         msecs--;
                         mdelay(1);
                 }