[PATCH v2 3/3] EDAC/versalnet: Fix device_register() error handling in init_one_mc()

Prasanna Kumar T S M
2026-04-01T11:19:03Z

When device_register() fails, it must be followed by put_device()
rather than kfree(), because device_register() calls
device_initialize() which sets up the device refcount. The matching
release function versal_edac_release() handles the actual kfree().

To simplify error handling and avoid complex unwinding, split
device_register() into device_initialize() and device_add().
Initialize the device early so put_device() can be used in all
error paths.

Fixes: d5fe2fec6c40 ("EDAC: Add a driver for the AMD Versal NET DDR controller")
Cc: stable@vger.kernel.org
Signed-off-by: Prasanna Kumar T S M <ptsm@linux.microsoft.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
drivers/edac/versalnet_edac.c | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/edac/versalnet_edac.c b/drivers/edac/versalnet_edac.c
index 012c4f40994d..94580d3c3170 100644
--- a/drivers/edac/versalnet_edac.c
+++ b/drivers/edac/versalnet_edac.c
@@ -780,7 +780,7 @@ static int init_one_mc(struct mc_priv *priv, struct platform_device *pdev, int i
struct device *dev;
enum dev_type dt;
char name[MC_NAME_LEN];
- int rc;
+ int rc = -ENOMEM;

config = priv->adec[CONF + i * ADEC_NUM];
num_chans = FIELD_GET(MC5_NUM_CHANS_MASK, config);
@@ -812,23 +812,23 @@ static int init_one_mc(struct mc_priv *priv, struct platform_device *pdev, int i
layers[1].size = num_chans;
layers[1].is_virt_csrow = false;

- rc = -ENOMEM;
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return rc;

+ sprintf(name, "versal-net-ddrmc5-edac-%d", i);
+
+ dev->init_name = name;
+ dev->release = versal_edac_release;
+ device_initialize(dev);
+
mci = edac_mc_alloc(i, ARRAY_SIZE(layers), layers, sizeof(struct mc_priv));
if (!mci) {
edac_printk(KERN_ERR, EDAC_MC, "Failed memory allocation for MC%d\n", i);
goto err_dev_free;
}

- sprintf(name, "versal-net-ddrmc5-edac-%d", i);
-
- dev->init_name = name;
- dev->release = versal_edac_release;
-
- rc = device_register(dev);
+ rc = device_add(dev);
if (rc)
goto err_mc_free;

@@ -849,11 +849,11 @@ static int init_one_mc(struct mc_priv *priv, struct platform_device *pdev, int i
return 0;

err_unreg:
- device_unregister(mci->pdev);
+ device_del(dev);
err_mc_free:
edac_mc_free(mci);
err_dev_free:
- kfree(dev);
+ put_device(dev);

return rc;
}
--
2.49.0