From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pa0-x22b.google.com ([2607:f8b0:400e:c03::22b]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZtmZW-0008DM-Nf for linux-mtd@lists.infradead.org; Wed, 04 Nov 2015 01:09:08 +0000 Received: by pacdm15 with SMTP id dm15so10264677pac.3 for ; Tue, 03 Nov 2015 17:08:44 -0800 (PST) From: Brian Norris To: Cc: Richard Weinberger , Brian Norris , Jesper Nilsson , linux-cris-kernel@axis.com Subject: [PATCH] mtd: don't WARN about overloaded users of mtd->reboot_notifier.notifier_call Date: Tue, 3 Nov 2015 17:01:53 -0800 Message-Id: <1446598913-133086-1-git-send-email-computersforpeace@gmail.com> List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , There are multiple types of users of mtd->reboot_notifier.notifier_call: (1) A while back, the cfi_cmdset_000{1,2} chip drivers implemented a reboot notifier to (on a best effort basis) attempt to reset their flash chips before rebooting. (2) More recently, we implemented a common _reboot() hook so that MTD drivers (particularly, NAND flash) could better halt I/O operations without having to reimplement the same notifier boilerplate. Currently, the WARN_ONCE() condition here was written to handle (2), but at the same time it mis-diagnosed case (1) as an already-registered MTD. Let's fix this by having the WARN_ONCE() condition better imitate the condition that immediately follows it. (Wow, I don't know how I missed that one.) (Side note: Unfortunately, we can't yet combine the reboot notifier code for (1) and (2) with a patch like [1], because some users of (1) also use mtdconcat, and so the mtd_info struct from cfi_cmdset_000{1,2} won't actually get registered with mtdcore, and therefore their reboot notifier won't get registered.) [1] http://patchwork.ozlabs.org/patch/417981/ Suggested-by: Guenter Roeck Signed-off-by: Brian Norris Cc: Jesper Nilsson Cc: linux-cris-kernel@axis.com --- This is probably a 4.4 candidate drivers/mtd/mtdcore.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c index b1eea48c501d..a91cee90aef9 100644 --- a/drivers/mtd/mtdcore.c +++ b/drivers/mtd/mtdcore.c @@ -616,7 +616,8 @@ int mtd_device_parse_register(struct mtd_info *mtd, const char * const *types, * does cause problems with parse_mtd_partitions() above (e.g., * cmdlineparts will register partitions more than once). */ - WARN_ONCE(mtd->reboot_notifier.notifier_call, "MTD already registered\n"); + WARN_ONCE(mtd->_reboot && mtd->reboot_notifier.notifier_call, + "MTD already registered\n"); if (mtd->_reboot && !mtd->reboot_notifier.notifier_call) { mtd->reboot_notifier.notifier_call = mtd_reboot_notifier; register_reboot_notifier(&mtd->reboot_notifier); -- 2.6.0.rc2.230.g3dd15c0