[PATCH 2/6] mtd: core: clear out unregistered devices a bit more

From: Zev Weiss
Date: Wed Sep 29 2021 - 07:54:38 EST


This allows an MTD device that has been unregistered to be easily
re-registered later without triggering "already registered" warnings in
mtd_device_parse_register() and add_mtd_device().

Signed-off-by: Zev Weiss <zev@xxxxxxxxxxxxxxxxx>
---
drivers/mtd/mtdcore.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index c8fd7f758938..e22266f63ae9 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -747,6 +747,9 @@ int del_mtd_device(struct mtd_info *mtd)

device_unregister(&mtd->dev);

+ /* Clear dev so mtd can be safely re-registered later if desired */
+ memset(&mtd->dev, 0, sizeof(mtd->dev));
+
idr_remove(&mtd_idr, mtd->index);
of_node_put(mtd_get_of_node(mtd));

@@ -1018,8 +1021,10 @@ int mtd_device_unregister(struct mtd_info *master)
{
int err;

- if (master->_reboot)
+ if (master->_reboot) {
unregister_reboot_notifier(&master->reboot_notifier);
+ memset(&master->reboot_notifier, 0, sizeof(master->reboot_notifier));
+ }

if (master->otp_user_nvmem)
nvmem_unregister(master->otp_user_nvmem);
--
2.33.0