mailbox: mailbox-test: don't free the reused channel

[ Upstream commit 88ebadb ]

The RX channel can be aliased to the TX channel if it has a different
MMIO. This special case needs to be handled when freeing the channels
otherwise a double-free occurs.

Fixes: 8ea4484 ("mailbox: Add generic mechanism for testing Mailbox Controllers")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: Wolfram Sang

drivers/mailbox/mailbox-test.c

@@ -422,7 +422,7 @@ static int mbox_test_probe(struct platform_device *pdev)
 err_free_chans:
 	if (tdev->tx_channel)
 		mbox_free_channel(tdev->tx_channel);
-	if (tdev->rx_channel)
+	if (tdev->rx_channel && tdev->rx_channel != tdev->tx_channel)
 		mbox_free_channel(tdev->rx_channel);
 	return ret;
 }
@@ -435,7 +435,7 @@ static void mbox_test_remove(struct platform_device *pdev)
 
 	if (tdev->tx_channel)
 		mbox_free_channel(tdev->tx_channel);
-	if (tdev->rx_channel)
+	if (tdev->rx_channel && tdev->rx_channel != tdev->tx_channel)
 		mbox_free_channel(tdev->rx_channel);
 }