mailbox: Fix up error handling in mbox_request_channel()

mbox_request_channel() currently returns EBUSY in the event the controller
is not present or if of_xlate() fails, but in neither case is EBUSY really
appropriate.  Return EPROBE_DEFER if the controller is not yet present
and change of_xlate() to return an ERR_PTR instead of NULL so that the
error can be propagated back to the caller of mbox_request_channel().

Signed-off-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Acked-by: Suman Anna <s-anna@ti.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/mailbox/omap-mailbox.c b/drivers/mailbox/omap-mailbox.c
index 03f8545ba037..a3dbfd9c6479 100644
--- a/drivers/mailbox/omap-mailbox.c
+++ b/drivers/mailbox/omap-mailbox.c
@@ -639,18 +639,18 @@ static struct mbox_chan *omap_mbox_of_xlate(struct mbox_controller *controller,
 
         mdev = container_of(controller, struct omap_mbox_device, controller);
         if (WARN_ON(!mdev))
-                return NULL;
+                return ERR_PTR(-EINVAL);
 
         node = of_find_node_by_phandle(phandle);
         if (!node) {
                 pr_err("%s: could not find node phandle 0x%x\n",
                        __func__, phandle);
-                return NULL;
+                return ERR_PTR(-ENODEV);
         }
 
         mbox = omap_mbox_device_find(mdev, node->name);
         of_node_put(node);
-        return mbox ? mbox->chan : NULL;
+        return mbox ? mbox->chan : ERR_PTR(-ENOENT);
 }
 
 static int omap_mbox_probe(struct platform_device *pdev)