fix broken/dubious driver suspend() methods

Small driver suspend() fixes in preparation for the PRETHAW events:

 - Only compare message events for equality against PM_EVENT_* codes;
   not against integers, or using greater/less-than comparisons.
   (PM_EVENT_* should really become a __bitwise thing.)

 - Explicitly test for SUSPEND events (rather than not-something-else)
   before suspending devices.

 - Removes more of the confusion between a pm_message_t (wraps event code)
   and a "state" ... suspend() originally took a target system state.

These updates are correct and appropriate even without new PM_EVENT codes.

benh: "I think in the Mesh case, we should handle the freeze case as well or
we might get wild DMA."

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Greg KH <greg@kroah.com>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 11 insertions, 4 deletions

diff --git a/drivers/scsi/mesh.c b/drivers/scsi/mesh.c
index 592b52afe658..683fc7ae4b8f 100644
--- a/drivers/scsi/mesh.c
+++ b/drivers/scsi/mesh.c
@@ -1756,16 +1756,23 @@ static void set_mesh_power(struct mesh_state *ms, int state)
                 pmac_call_feature(PMAC_FTR_MESH_ENABLE, macio_get_of_node(ms->mdev), 0, 0);
                 msleep(10);
         }
-}                       
+}
 
 
 #ifdef CONFIG_PM
-static int mesh_suspend(struct macio_dev *mdev, pm_message_t state)
+static int mesh_suspend(struct macio_dev *mdev, pm_message_t mesg)
 {
         struct mesh_state *ms = (struct mesh_state *)macio_get_drvdata(mdev);
         unsigned long flags;
 
-        if (state.event == mdev->ofdev.dev.power.power_state.event || state.event < 2)
+        switch (mesg.event) {
+        case PM_EVENT_SUSPEND:
+        case PM_EVENT_FREEZE:
+                break;
+        default:
+                return 0;
+        }
+        if (mesg.event == mdev->ofdev.dev.power.power_state.event)
                 return 0;
 
         scsi_block_requests(ms->host);
@@ -1780,7 +1787,7 @@ static int mesh_suspend(struct macio_dev *mdev, pm_message_t state)
         disable_irq(ms->meshintr);
         set_mesh_power(ms, 0);
 
-        mdev->ofdev.dev.power.power_state = state;
+        mdev->ofdev.dev.power.power_state = mesg;
 
         return 0;
 }