Re: [PATCH v2] mtd: rawnand: mark expected switch fall-throughs

Miquel Raynal
2019-04-12T07:24:48Z

Hi Gustavo,

"Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote on Thu, 11 Apr
2019 17:20:31 -0500:

> On 4/11/19 5:10 PM, Miquel Raynal wrote:
> > Hi Gustavo,
> >
> > "Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote on Thu, 11 Apr
> > 2019 13:30:31 -0500:
> >
> >> Hi Miquel,
> >>
> >> On 2/5/19 6:55 AM, Miquel Raynal wrote:
> >> [..]
> >>>> @@ -3280,12 +3280,14 @@ static void onenand_check_features(struct mtd_info *mtd)
> >>>> if ((this->version_id & 0xf) == 0xe)
> >>>> this->options |= ONENAND_HAS_NOP_1;
> >>>> }
> >>>> + /* fall through */
> >>>>
> >>>> case ONENAND_DEVICE_DENSITY_2Gb:
> >>>> /* 2Gb DDP does not have 2 plane */
> >>>> if (!ONENAND_IS_DDP(this))
> >>>> this->options |= ONENAND_HAS_2PLANE;
> >>>> this->options |= ONENAND_HAS_UNLOCK_ALL;
> >>>> + /* fall through */
> >>>
> >>> This looks strange.
> >>>
> >>> In ONENAND_DEVICE_DENSITY_2Gb:
> >>> ONENAND_HAS_UNLOCK_ALL is set unconditionally.
> >>>
> >>> But then, under ONENAND_DEVICE_DENSITY_1Gb, the same option is set only
> >>> if process is evaluated to true.
> >>>
> >>> Same problem with ONENAND_HAS_2PLANE:
> >>> - it is set in ONENAND_DEVICE_DENSITY_4Gb only if ONENAND_IS_DDP()
> >>> - it is unset in ONENAND_DEVICE_DENSITY_2Gb only if !ONENAND_IS_DDP()
> >>>
> >>> Maybe this portion should be reworked because I am unsure if this is a
> >>> missing fall through or a bug.
> >>>
> >>
> >> I wonder if you had the chance to take a look into this piece of code.
> >>
> >> Thanks
> >> --
> >> Gustavo
> >
> > What do you mean?
> >
>
> You commented that the piece of code above should be reworked. So, it wasn't
> clear to me who was going to do that; and that's why I'm asking if you took
> a look into it and finally determine whether we are dealing with an actual
> bug or a false positive.

Yes please do it, I don't have the time and I don't plan to do it
myself.

Thanks,
Miquèl