[PATCH v2] mtd: leave the device type unset when naming fails

[James Hilliard]

add_mtd_device() uses dev.type to reject a second registration of the
same MTD. It sets that field before dev_set_name(), but the failure path
for the name allocation leaves it set even though no device was
registered. Retrying registration then warns and fails with -EEXIST.

Set the type only after naming succeeds. The later registration error
paths already clear it before releasing the device.

Fixes: 6697dae1e2da ("mtd: capture device name setting failure when adding mtd")
Cc: stable at vger.kernel.org
Signed-off-by: James Hilliard <james.hilliard1 at gmail.com>
---
Changes in v2:
- Correct the Fixes tag to identify the commit that added the
  device-name allocation error path.
- Link to v1: https://patch.msgid.link/20261108-submit-mtd-devname-retry-v1-v1-1-a67f332c54dd@gmail.com

To: Miquel Raynal <miquel.raynal at bootlin.com>
To: Richard Weinberger <richard at nod.at>
To: Vignesh Raghavendra <vigneshr at ti.com>
To: Edward Adam Davis <eadavis at qq.com>
Cc: linux-mtd at lists.infradead.org
Cc: linux-kernel at vger.kernel.org
---
 drivers/mtd/mtdcore.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 491a27d0315f..4f62a13dc481 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -798,12 +798,12 @@ int add_mtd_device(struct mtd_info *mtd)
 	/* Caller should have set dev.parent to match the
 	 * physical device, if appropriate.
 	 */
-	mtd->dev.type = &mtd_devtype;
 	mtd->dev.class = &mtd_class;
 	mtd->dev.devt = MTD_DEVT(i);
 	error = dev_set_name(&mtd->dev, "mtd%d", i);
 	if (error)
 		goto fail_devname;
+	mtd->dev.type = &mtd_devtype;
 	dev_set_drvdata(&mtd->dev, mtd);
 	mtd_check_of_node(mtd);
 	of_node_get(mtd_get_of_node(mtd));

---
base-commit: 1c1a342aceec79528b3ba51f376eca2be5928fe7
change-id: 20261108-submit-mtd-devname-retry-v1-3f7cb2ed8083

Best regards,
--  
James Hilliard <james.hilliard1 at gmail.com>