[PATCH 1/6] remoteproc: imx_rproc: Fix runtime PM cleanup order and error handling

[Peng Fan]

The order of runtime PM API calls in the remove path is wrong.
pm_runtime_put() should be called before pm_runtime_disable(), per the
runtime PM guidelines. Calling pm_runtime_disable() prematurely can
lead to incorrect reference counting and improper device suspend behavior.

Additionally, proper cleanup should be done when rproc_add() fails by
invoking both pm_runtime_put() and pm_runtime_disable() to avoid leaving
the device in an inconsistent power state.

With using devm_pm_runtime_enable() for automatic resource management and
introducing a devres-managed cleanup action imx_rproc_pm_runtime_put() to
enforce correct PM API usage and simplify error paths, the upper two
issues could be fixed. Also print out error log in case of error.

Fixes: a876a3aacc43 ("remoteproc: imx_rproc: detect and attach to pre-booted 
remote cores")
Cc: Ulf Hansson <ulf.hans...@linaro.org>
Cc: Hiago De Franco <hiago.fra...@toradex.com>
Signed-off-by: Peng Fan <peng....@nxp.com>
---
 drivers/remoteproc/imx_rproc.c | 24 +++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/drivers/remoteproc/imx_rproc.c b/drivers/remoteproc/imx_rproc.c
index 
bb25221a4a8987ff427d68e2a5535f0e156b0097..12305f36552fb5265b0953a099ea0d561880e3ff
 100644
--- a/drivers/remoteproc/imx_rproc.c
+++ b/drivers/remoteproc/imx_rproc.c
@@ -1046,6 +1046,13 @@ static int imx_rproc_sys_off_handler(struct sys_off_data 
*data)
        return NOTIFY_DONE;
 }
 
+static void imx_rproc_pm_runtime_put(void *data)
+{
+       struct device *dev = data;
+
+       pm_runtime_put(dev);
+}
+
 static int imx_rproc_probe(struct platform_device *pdev)
 {
        struct device *dev = &pdev->dev;
@@ -1125,12 +1132,23 @@ static int imx_rproc_probe(struct platform_device *pdev)
        }
 
        if (dcfg->method == IMX_RPROC_SCU_API) {
-               pm_runtime_enable(dev);
+               ret = devm_pm_runtime_enable(dev);
+               if (ret) {
+                       dev_err(dev, "Failed to enable runtime PM, %d\n", ret);
+                       goto err_put_clk;
+               }
+
                ret = pm_runtime_resume_and_get(dev);
                if (ret) {
                        dev_err(dev, "pm_runtime get failed: %d\n", ret);
                        goto err_put_clk;
                }
+
+               ret = devm_add_action_or_reset(dev, imx_rproc_pm_runtime_put, 
dev);
+               if (ret) {
+                       dev_err(dev, "Failed to add devm disable pm action: 
%d\n", ret);
+                       goto err_put_clk;
+               }
        }
 
        ret = rproc_add(rproc);
@@ -1158,10 +1176,6 @@ static void imx_rproc_remove(struct platform_device 
*pdev)
        struct rproc *rproc = platform_get_drvdata(pdev);
        struct imx_rproc *priv = rproc->priv;
 
-       if (priv->dcfg->method == IMX_RPROC_SCU_API) {
-               pm_runtime_disable(priv->dev);
-               pm_runtime_put(priv->dev);
-       }
        clk_disable_unprepare(priv->clk);
        rproc_del(rproc);
        imx_rproc_put_scu(rproc);

-- 
2.37.1