[POWERPC] check firmware state before suspending

Currently the kernel blindly halts all the processors and calls the
ibm,suspend-me rtas call.  If the firmware is not in the correct
state, we then re-start all the processors and return.  It is much
smarter to first check the firmware state, and only if it is waiting,
call the ibm,suspend-me call.

Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 22 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 13496f319855..fd15e3e3bb33 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -593,9 +593,31 @@ out:
 static int rtas_ibm_suspend_me(struct rtas_args *args)
 {
         int i;
+        long state;
+        long rc;
+        unsigned long dummy;
 
         struct rtas_suspend_me_data data;
 
+        /* Make sure the state is valid */
+        rc = plpar_hcall(H_VASI_STATE,
+                         ((u64)args->args[0] << 32) | args->args[1],
+                         0, 0, 0,
+                         &state, &dummy, &dummy);
+
+        if (rc) {
+                printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned %ld\n",rc);
+                return rc;
+        } else if (state == H_VASI_ENABLED) {
+                args->args[args->nargs] = RTAS_NOT_SUSPENDABLE;
+                return 0;
+        } else if (state != H_VASI_SUSPENDING) {
+                printk(KERN_ERR "rtas_ibm_suspend_me: vasi_state returned state %ld\n",
+                       state);
+                args->args[args->nargs] = -1;
+                return 0;
+        }
+
         data.waiting = 1;
         data.args = args;