Re: [PATCH v2 20/53] mtd: nand: denali: do not set mtd->name

Masahiro Yamada
2017-03-29T01:19:47Z

Hi Boris,

2017-03-29 6:40 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
> On Wed, 29 Mar 2017 06:32:24 +0900
> Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>
>> Hi Boris,
>>
>> 2017-03-28 0:31 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
>> > On Wed, 22 Mar 2017 23:07:27 +0900
>> > Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>> >
>> >> This will be filled by nand_scan_ident() later.
>> >>
>> >> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
>> >> ---
>> >>
>> >> Changes in v2: None
>> >>
>> >> drivers/mtd/nand/denali.c | 1 -
>> >> 1 file changed, 1 deletion(-)
>> >>
>> >> diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
>> >> index 3badb1d..1706975 100644
>> >> --- a/drivers/mtd/nand/denali.c
>> >> +++ b/drivers/mtd/nand/denali.c
>> >> @@ -1495,7 +1495,6 @@ int denali_init(struct denali_nand_info *denali)
>> >>
>> >> /* now that our ISR is registered, we can enable interrupts */
>> >> denali_set_intr_modes(denali, true);
>> >> - mtd->name = "denali-nand";
>> >
>> > Are you sure this is safe to do that? When mtd->name is NULL, the core
>> > takes the parent name, and in the denali_dt case it's not "denali-nand",
>> > which means you're breaking mtdparts compat.
>>
>> How big impact is this?
>
> Breaking boot on some platforms (those defining partitions through
> mtdparts= cmdline parameter), which is not negligible :P.
>
>>
>> I think a bootloader could give mtdparts=denali-nand:...
>> but, now we are able to have partitions in DT nodes.
>
> Just because you have a new way to describe partitions (using DT) does
> not mean people are not using the old one (mtdparts= parameter).

I thought DT-node derived name can identify the hardware
even if multiple Denali controllers exist on an SoC.

Anyway, I admit this is a kind of breakage.

If this one is reject, I will drop it drop v3.

--
Best Regards
Masahiro Yamada