[PATCH v2 3/4] mailbox: mailbox-test: initialize struct earlier

[Wolfram Sang]

The waitqueue must be initialized before the debugfs files are created
because from that time, requests from userspace can already be made.
Similarily, drvdata and spinlock needs to be initialized before we
request the channel, otherwise dangling irqs might run into problems
like a NULL pointer exception.

Fixes: 8ea4484d0c2b ("mailbox: Add generic mechanism for testing Mailbox Controllers")
Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
---
 drivers/mailbox/mailbox-test.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/mailbox/mailbox-test.c b/drivers/mailbox/mailbox-test.c
index 0a56b593fcac..ec591616fe46 100644
--- a/drivers/mailbox/mailbox-test.c
+++ b/drivers/mailbox/mailbox-test.c
@@ -382,6 +382,12 @@ static int mbox_test_probe(struct platform_device *pdev)
 	if (!tdev)
 		return -ENOMEM;
 
+	tdev->dev = &pdev->dev;
+	spin_lock_init(&tdev->lock);
+	mutex_init(&tdev->mutex);
+	init_waitqueue_head(&tdev->waitq);
+	platform_set_drvdata(pdev, tdev);
+
 	/* It's okay for MMIO to be NULL */
 	tdev->tx_mmio = mbox_test_ioremap(pdev, 0);
 
@@ -400,12 +406,6 @@ static int mbox_test_probe(struct platform_device *pdev)
 	if (!tdev->rx_channel && (tdev->rx_mmio != tdev->tx_mmio))
 		tdev->rx_channel = tdev->tx_channel;
 
-	tdev->dev = &pdev->dev;
-	platform_set_drvdata(pdev, tdev);
-
-	spin_lock_init(&tdev->lock);
-	mutex_init(&tdev->mutex);
-
 	if (tdev->rx_channel) {
 		tdev->rx_buffer = devm_kzalloc(&pdev->dev,
 					       MBOX_MAX_MSG_LEN, GFP_KERNEL);
@@ -419,7 +419,6 @@ static int mbox_test_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_free_chans;
 
-	init_waitqueue_head(&tdev->waitq);
 	dev_info(&pdev->dev, "Successfully registered\n");
 
 	return 0;
-- 
2.51.0