Re: [PATCH 2/2] mtd: nand: Get rid of needless 'goto'

Boris Brezillon
2016-07-19T18:55:24Z

On Tue, 19 Jul 2016 11:48:04 -0700
Andrey Smirnov <andrew.smirnov@gmail.com> wrote:

> On Tue, Jul 19, 2016 at 11:30 AM, Brian Norris
> <computersforpeace@gmail.com> 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 <andrew.smirnov@gmail.com>
> >> ---
> >> 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)
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.

>
> instead of the switch statement, IMHO, this way it is more obvious
> that this codepath is just arguments correctness checking.
>
> Andrey