mtd: avoid registering reboot notifier twice
Calling mtd_device_parse_register with the same mtd_info
(e.g. registering several partitions on a single device)
would add the same reboot notifier twice, causing an
infinte loop in notifier_chain_register during boot up.
Signed-off-by: Niklas Cassel <nks@flawful.org>
[Brian: add FIXME comments]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index cbc0fc4..52eea93 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -577,7 +577,15 @@
err = -ENODEV;
}
- if (mtd->_reboot) {
+ /*
+ * FIXME: some drivers unfortunately call this function more than once.
+ * So we have to check if we've already assigned the reboot notifier.
+ *
+ * Generally, we can make multiple calls work for most cases, but it
+ * does cause problems with parse_mtd_partitions() above (e.g.,
+ * cmdlineparts will register partitions more than once).
+ */
+ if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
register_reboot_notifier(&mtd->reboot_notifier);
}
