Re: [PATCH v3 1/3] mtd: rawnand: denali_dt: add more clocks based on IP datasheet

[Masahiro Yamada]

Hi Boris,


2018-06-18 16:46 GMT+09:00 Boris Brezillon <boris.brezillon@xxxxxxxxxxx>:
> On Mon, 18 Jun 2018 09:09:02 +0200
> Richard Weinberger <richard@xxxxxx> wrote:
>
>> Am Freitag, 15. Juni 2018, 03:18:50 CEST schrieb Masahiro Yamada:
>> > According to the Denali User's Guide, this IP needs three clocks:
>> >
>> >  - clk: controller core clock
>> >
>> >  - clk_x: bus interface clock
>> >
>> >  - ecc_clk: clock at which ECC circuitry is run
>> >
>> > Currently, denali_dt.c requires a single anonymous clock and its
>> > frequency.  However, the driver needs to get the frequency of "clk_x"
>> > not "clk".  This is confusing because people tend to assume the
>> > anonymous clock means the core clock.  In fact, I got a report of
>> > SOCFPGA breakage because the timing parameters are calculated based
>> > on a wrong frequency.
>> >
>> > Instead of the cheesy implementation, the clocks in the real hardware
>> > should be represented in the driver and the DT-binding.
>> >
>> > However, adding new clocks would break the existing platforms.  For the
>> > backward compatibility, the driver still accepts a single clock just as
>> > before.  If clk_x is missing, clk_x_rate is set to a hardcoded value.
>> > This is fine for existing DT of Socionext UniPhier, and also fixes the
>> > issue of Altera (Intel) SOCFPGA because both platforms use 200 MHz for
>> > the bus interface clock.
>> >
>> > Fixes: 1bb88666775e ("mtd: nand: denali: handle timing parameters by setup_data_interface()")
>> > Cc: linux-stable <stable@xxxxxxxxxxxxxxx> #4.14+
>> > Reported-by: Richard Weinberger <richard@xxxxxx>
>> > Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
>>
>> Reviewed-by: Richard Weinberger <richard@xxxxxx>
>
> Maybe a
>
> Tested-by: Richard Weinberger <richard@xxxxxx>
>
> ?
>
>> Reported-by: Philipp Rosenberger <p.rosenberger@xxxxxxxxxxxxx>
>
> Should I replace your Reported-by by this one or simply add it?


I think it is good to have Reported-by
both from Philipp and Richard.


Thanks.



-- 
Best Regards
Masahiro Yamada