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

[Richard Weinberger]

----- UrsprÃngliche Mail -----
> Von: "Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx>
> An: "Miquel Raynal" <miquel.raynal@xxxxxxxxxxx>
> CC: "David Woodhouse" <dwmw2@xxxxxxxxxxxxx>, "Brian Norris" <computersforpeace@xxxxxxxxx>, "Boris Brezillon"
> <bbrezillon@xxxxxxxxxx>, "Marek Vasut" <marek.vasut@xxxxxxxxx>, "richard" <richard@xxxxxx>, "linux-mtd"
> <linux-mtd@xxxxxxxxxxxxxxxxxxx>, "linux-kernel" <linux-kernel@xxxxxxxxxxxxxxx>, "Kees Cook" <keescook@xxxxxxxxxxxx>
> Gesendet: Dienstag, 7. Mai 2019 16:54:12
> Betreff: Re: [PATCH] mtd: cfi_util: mark expected switch fall-throughs

> Hi all,
> 
> Thanks a lot for this, Richard:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git/log/?h=mtd%2Fnext&qt=grep&q=fall-through
> 
> There are only two of these warnings left to be addressed in
> MTD[1]:
> 
>        > @@ -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.
> 
> 
> Thanks
> --
> Gustavo
> 
> [1] https://lore.kernel.org/patchwork/patch/1036251/

Did we miss this patch? AFAICT it is in -next too.

Thanks,
//richard