[PATCH V6 03/12] mailbox: Fix up error handling in mbox_request_channel()

Andrew Bresticker
2014-11-25T00:17:37Z

From: Benson Leung <bleung@chromium.org>

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>
---
No changes from v5.
New for v5.
---
drivers/mailbox/mailbox.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
index afcb430..955c0a7 100644
--- a/drivers/mailbox/mailbox.c
+++ b/drivers/mailbox/mailbox.c
@@ -315,7 +315,7 @@ struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index)
return ERR_PTR(-ENODEV);
}

- chan = NULL;
+ chan = ERR_PTR(-EPROBE_DEFER);
list_for_each_entry(mbox, &mbox_cons, node)
if (mbox->dev->of_node == spec.np) {
chan = mbox->of_xlate(mbox, &spec);
@@ -324,7 +324,12 @@ struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index)

of_node_put(spec.np);

- if (!chan || chan->cl || !try_module_get(mbox->dev->driver->owner)) {
+ if (IS_ERR(chan)) {
+ mutex_unlock(&con_mutex);
+ return chan;
+ }
+
+ if (chan->cl || !try_module_get(mbox->dev->driver->owner)) {
dev_dbg(dev, "%s: mailbox not free\n", __func__);
mutex_unlock(&con_mutex);
return ERR_PTR(-EBUSY);
@@ -387,7 +392,7 @@ of_mbox_index_xlate(struct mbox_controller *mbox,
int ind = sp->args[0];

if (ind >= mbox->num_chans)
- return NULL;
+ return ERR_PTR(-EINVAL);

return &mbox->chans[ind];
}
--
2.1.0.rc2.206.gedb03e5