From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from down.free-electrons.com ([37.187.137.238] helo=mail.free-electrons.com) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1amLyg-0004L8-7l for linux-mtd@lists.infradead.org; Sat, 02 Apr 2016 13:52:39 +0000 Date: Sat, 2 Apr 2016 15:52:16 +0200 From: Boris Brezillon To: Brian Norris Cc: Ezequiel Garcia , linux-mtd@lists.infradead.org, Richard Weinberger , David Woodhouse Subject: Re: [PATCH 1/2] mtd: nand: Drop mtd.owner requirement in nand_scan Message-ID: <20160402155216.48866776@bbrezillon> In-Reply-To: <20160401222649.GK2545@google.com> References: <1459546164-6269-1-git-send-email-ezequiel@vanguardiasur.com.ar> <1459546164-6269-2-git-send-email-ezequiel@vanguardiasur.com.ar> <20160401222649.GK2545@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 1 Apr 2016 15:26:49 -0700 Brian Norris wrote: > On Fri, Apr 01, 2016 at 06:29:23PM -0300, Ezequiel Garcia wrote: > > Since commit 807f16d4db95 ("mtd: core: set some defaults > > when dev.parent is set"), it's now legal for drivers > > to call nand_scan and nand_scan_ident without setting > > mtd.owner. > > > > Drop the check and while at it remove the BUG() abuse. > > > > Signed-off-by: Ezequiel Garcia Acked-by: Boris Brezillon > > --- > > drivers/mtd/nand/nand_base.c | 10 +--------- > > 1 file changed, 1 insertion(+), 9 deletions(-) > > > > diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c > > index c3733a10a6e7..befa04ef4a04 100644 > > --- a/drivers/mtd/nand/nand_base.c > > +++ b/drivers/mtd/nand/nand_base.c > > @@ -4013,7 +4013,6 @@ static int nand_dt_init(struct nand_chip *chip) > > * This is the first phase of the normal nand_scan() function. It reads the > > * flash ID and sets up MTD fields accordingly. > > * > > - * The mtd->owner field must be set to the module of the caller. > > */ > > int nand_scan_ident(struct mtd_info *mtd, int maxchips, > > struct nand_flash_dev *table) > > @@ -4433,19 +4432,12 @@ EXPORT_SYMBOL(nand_scan_tail); > > * > > * This fills out all the uninitialized function pointers with the defaults. > > * The flash ID is read and the mtd/chip structures are filled with the > > - * appropriate values. The mtd->owner field must be set to the module of the > > - * caller. > > + * appropriate values. > > */ > > int nand_scan(struct mtd_info *mtd, int maxchips) > > { > > int ret; > > > > - /* Many callers got this wrong, so check for it for a while... */ > > - if (!mtd->owner && caller_is_module()) { > > - pr_crit("%s called with NULL mtd->owner!\n", __func__); > > - BUG(); > > - } > > Ooh, yikes! Forgot this was there. I guess no one noticed, because fewer > drivers are using plain nand_scan() these days (instead of splitting up > nand_scan_ident() and nand_scan_tail()), and also, many NAND users don't > run their drivers as modules. > > Anyway, this is probably worth -stable, right? (i.e., "Fixes: > 807f16d4db95 ..." and "Cc: ") > > I can take this directly, or Boris, if you feel like there will be other > for-v4.5 NAND material, you can queue this up instead. No, take it directly. On a more general note, not sure creating a nand/fixes branch and sending you PRs after each -rc (if fixes are available of course) is really efficient. Maybe I'm wrong, but I don't expect to see more than a couple of fixes per release, and it's probably better if you keep taking them directly (with my acks). What do you think? -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com