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mtd: warn when registering the same master many times

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When CONFIG_MTD_PARTITIONED_MASTER=y, it is fatal to call
mtd_device_parse_register() twice on the same MTD, as we try to register
the same device/kobject multipile times.

When CONFIG_MTD_PARTITIONED_MASTER=n, calling
mtd_device_parse_register() is more of just a nuisance, as we can mostly
navigate around any conflicting actions.

But anyway, doing so is a Bad Thing (TM), and we should complain loudly
for any drivers that try to do this.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
This commit is contained in:
Brian Norris 2015-06-01 16:17:20 -07:00
parent 3e00ed0e98
commit be0dbff8b4
1 changed files with 9 additions and 0 deletions
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9
drivers/mtd/mtdcore.c
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@ -387,6 +387,14 @@ int add_mtd_device(struct mtd_info *mtd)
struct mtd_notifier *not; struct mtd_notifier *not;
int i, error; int i, error;
/*
* May occur, for instance, on buggy drivers which call
* mtd_device_parse_register() multiple times on the same master MTD,
* especially with CONFIG_MTD_PARTITIONED_MASTER=y.
*/
if (WARN_ONCE(mtd->backing_dev_info, "MTD already registered\n"))
return -EEXIST;
mtd->backing_dev_info = &mtd_bdi; mtd->backing_dev_info = &mtd_bdi;
BUG_ON(mtd->writesize == 0); BUG_ON(mtd->writesize == 0);
@ -606,6 +614,7 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types,
* does cause problems with parse_mtd_partitions() above (e.g., * does cause problems with parse_mtd_partitions() above (e.g.,
* cmdlineparts will register partitions more than once). * cmdlineparts will register partitions more than once).
*/ */
WARN_ONCE(mtd->reboot_notifier.notifier_call, "MTD already registered\n");
if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) { if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) {
mtd->reboot_notifier.notifier_call = mtd_reboot_notifier; mtd->reboot_notifier.notifier_call = mtd_reboot_notifier;
register_reboot_notifier(&mtd->reboot_notifier); register_reboot_notifier(&mtd->reboot_notifier);