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>
This commit is contained in:
Niklas Cassel 2015-02-01 02:08:50 +01:00 committed by Brian Norris
parent d164ea3267
commit e1dd8641c8
1 changed files with 9 additions and 1 deletions

View File

@ -577,7 +577,15 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
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);
}