From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pa0-x244.google.com ([2607:f8b0:400e:c03::244]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bPawH-0001YW-B9 for linux-mtd@lists.infradead.org; Tue, 19 Jul 2016 19:44:21 +0000 Received: by mail-pa0-x244.google.com with SMTP id cf3so1833525pad.2 for ; Tue, 19 Jul 2016 12:44:01 -0700 (PDT) Date: Tue, 19 Jul 2016 12:43:58 -0700 From: Brian Norris To: Boris Brezillon Cc: Andrey Smirnov , linux-mtd@lists.infradead.org, Richard Weinberger , David Woodhouse , linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] mtd: nand: Get rid of needless 'goto' Message-ID: <20160719194358.GB143334@google.com> References: <1468942904-26464-1-git-send-email-andrew.smirnov@gmail.com> <1468942904-26464-2-git-send-email-andrew.smirnov@gmail.com> <20160719183047.GC85399@google.com> <20160719205521.3a816b19@bbrezillon> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160719205521.3a816b19@bbrezillon> List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi, On Tue, Jul 19, 2016 at 08:55:21PM +0200, Boris Brezillon wrote: > On Tue, 19 Jul 2016 11:48:04 -0700 > Andrey Smirnov wrote: > > > On Tue, Jul 19, 2016 at 11:30 AM, Brian Norris > > wrote: > > > On Tue, Jul 19, 2016 at 08:41:44AM -0700, Andrey Smirnov wrote: > > >> Using "goto" in that "switch" statement only makes it harder to follow > > >> control flow and doesn't bring any advantages. Rewrite the code to avoid > > >> using "goto". > > >> > > >> Signed-off-by: Andrey Smirnov > > >> --- > > >> drivers/mtd/nand/nand_base.c | 13 +++++-------- > > >> 1 file changed, 5 insertions(+), 8 deletions(-) > > >> > > >> diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c > > >> index 57043a6..8fa5536 100644 > > >> --- a/drivers/mtd/nand/nand_base.c > > >> +++ b/drivers/mtd/nand/nand_base.c > > >> @@ -2139,18 +2139,15 @@ static int nand_read_oob(struct mtd_info *mtd, loff_t from, > > >> case MTD_OPS_PLACE_OOB: > > >> case MTD_OPS_AUTO_OOB: > > >> case MTD_OPS_RAW: > > >> + if (!ops->datbuf) > > >> + ret = nand_do_read_oob(mtd, from, ops); > > >> + else > > >> + ret = nand_do_read_ops(mtd, from, ops); > > >> break; > > >> - > > >> default: > > >> - goto out; > > >> + break; > > >> } > > >> > > >> - if (!ops->datbuf) > > >> - ret = nand_do_read_oob(mtd, from, ops); > > >> - else > > >> - ret = nand_do_read_ops(mtd, from, ops); > > >> - > > >> -out: > > >> nand_release_device(mtd); > > >> return ret; > > >> } > > > > > > The default case is really just a catch-all error case. We don't > > > actually even need the nand_get_device() call for that... can we just > > > do this instead? > > > > Sure, although, if you don't mind, I'd rather you used: > > > > if (ops->mode != MTD_OPS_PLACE_OOB && > > ops->mode != MTD_OPS_AUTO_OOB && > > ops->mode != MTD_OPS_RAW) > > return -ENOTSUPP; > > Or just > > if (ops->mode < MTD_OPS_PLACE_OOB || ops->mode > MTD_OPS_RAW) ops->mode is unsigned. And this seems a little more fragile, assuming the enum layout. > return -ENOTSUPP; > > Anyway, I'm fine with all different versions as long as you don't take > the nand lock if the mode is incorrect, so I'll let Brian decide. Whatever Andrey prefers is his choice to send, and I don't have much more preference than the above comment. I'd take either mine or Andrey's second solution above. Brian > > > > instead of the switch statement, IMHO, this way it is more obvious > > that this codepath is just arguments correctness checking. > > > > Andrey >