[PATCH] firmware: imx: scu: manage mailbox channels and global handle

[Pengpeng Hou]

imx_scu_probe() requests mailbox channels with the non-managed
mbox_request_channel_byname() helper and then publishes sc_ipc through
the global imx_sc_ipc_handle.  Later probe failures, including child
population failure, can leave the channels and global handle live after
the probe has failed.

Register devres actions to free each mailbox channel and clear the global
handle.  Also depopulate partially created child devices when
devm_of_platform_populate() reports an error.

Signed-off-by: Pengpeng Hou <pengpeng at iscas.ac.cn>
---
 drivers/firmware/imx/imx-scu.c | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/imx/imx-scu.c b/drivers/firmware/imx/imx-scu.c
index 67b267a7408a..203aac421252 100644
--- a/drivers/firmware/imx/imx-scu.c
+++ b/drivers/firmware/imx/imx-scu.c
@@ -82,6 +82,17 @@ static int imx_sc_linux_errmap[IMX_SC_ERR_LAST] = {
 
 static struct imx_sc_ipc *imx_sc_ipc_handle;
 
+static void imx_scu_free_mbox_chan(void *data)
+{
+	mbox_free_channel(data);
+}
+
+static void imx_scu_clear_handle(void *data)
+{
+	if (imx_sc_ipc_handle == data)
+		imx_sc_ipc_handle = NULL;
+}
+
 static inline int imx_sc_to_linux_errno(int errno)
 {
 	if (errno >= IMX_SC_ERR_NONE && errno < IMX_SC_ERR_LAST)
@@ -321,6 +332,11 @@ static int imx_scu_probe(struct platform_device *pdev)
 		dev_dbg(dev, "request mbox chan %s\n", chan_name);
 		/* chan_name is not used anymore by framework */
 		kfree(chan_name);
+
+		ret = devm_add_action_or_reset(dev, imx_scu_free_mbox_chan,
+					       sc_chan->ch);
+		if (ret)
+			return ret;
 	}
 
 	sc_ipc->dev = dev;
@@ -330,6 +346,9 @@ static int imx_scu_probe(struct platform_device *pdev)
 	init_completion(&sc_ipc->done);
 
 	imx_sc_ipc_handle = sc_ipc;
+	ret = devm_add_action_or_reset(dev, imx_scu_clear_handle, sc_ipc);
+	if (ret)
+		return ret;
 
 	ret = imx_scu_soc_init(dev);
 	if (ret)
@@ -342,7 +361,11 @@ static int imx_scu_probe(struct platform_device *pdev)
 
 	dev_info(dev, "NXP i.MX SCU Initialized\n");
 
-	return devm_of_platform_populate(dev);
+	ret = devm_of_platform_populate(dev);
+	if (ret)
+		of_platform_depopulate(dev);
+
+	return ret;
 }
 
 static const struct of_device_id imx_scu_match[] = {
-- 
2.50.1 (Apple Git-155)