[PATCH AUTOSEL 4.4 29/35] mailbox: handle failed named mailbox channel request

[Sasha Levin <sashal@kernel.org>]

From: morten petersen <morten_bp@live.dk>

[ Upstream commit 25777e5784a7b417967460d4fcf9660d05a0c320 ]

Previously, if mbox_request_channel_byname was used with a name
which did not exist in the "mbox-names" property of a mailbox
client, the mailbox corresponding to the last entry in the
"mbox-names" list would be incorrectly selected.
With this patch, -EINVAL is returned if the named mailbox is
not found.

Signed-off-by: Morten Borup Petersen <morten_bp@live.dk>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/mailbox/mailbox.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
index 9cf826df89b1..b4ad85251cf7 100644
--- a/drivers/mailbox/mailbox.c
+++ b/drivers/mailbox/mailbox.c
@@ -389,11 +389,13 @@ struct mbox_chan *mbox_request_channel_byname(struct mbox_client *cl,
 
 	of_property_for_each_string(np, "mbox-names", prop, mbox_name) {
 		if (!strncmp(name, mbox_name, strlen(name)))
-			break;
+			return mbox_request_channel(cl, index);
 		index++;
 	}
 
-	return mbox_request_channel(cl, index);
+	dev_err(cl->dev, "%s() could not locate channel named \"%s\"\n",
+		__func__, name);
+	return ERR_PTR(-EINVAL);
 }
 EXPORT_SYMBOL_GPL(mbox_request_channel_byname);
 
-- 
2.20.1