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

From: Richard Weinberger <richard@nod.at>
To: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Boris Brezillon <boris.brezillon@bootlin.com>,
	linux-mtd <linux-mtd@lists.infradead.org>,
	Rob Herring <robh+dt@kernel.org>,
	Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
	"linux-stable #4 . 14+" <stable@vger.kernel.org>,
	DTML <devicetree@vger.kernel.org>,
	Miquel Raynal <miquel.raynal@bootlin.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Marek Vasut <marek.vasut@gmail.com>,
	Brian Norris <computersforpeace@gmail.com>,
	David Woodhouse <dwmw2@infradead.org>,
	Mark Rutland <mark.rutland@arm.com>
Subject: Re: [PATCH v3 1/3] mtd: rawnand: denali_dt: add more clocks based on IP datasheet
Date: Tue, 19 Jun 2018 12:46:04 +0200	[thread overview]
Message-ID: <2133216.znqypcnggC@blindfold> (raw)
In-Reply-To: <CAK7LNASCKhxtoOc3QdECF6p8BaBjab7Ed2y9Og+8LhvX4O83-Q@mail.gmail.com>

Am Dienstag, 19. Juni 2018, 10:07:26 CEST schrieb Masahiro Yamada:
> Hi Boris,
> 
> 
> 2018-06-18 16:46 GMT+09:00 Boris Brezillon <boris.brezillon@bootlin.com>:
> > On Mon, 18 Jun 2018 09:09:02 +0200
> > Richard Weinberger <richard@nod.at> 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@vger.kernel.org> #4.14+
> >> > Reported-by: Richard Weinberger <richard@nod.at>
> >> > Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
> >>
> >> Reviewed-by: Richard Weinberger <richard@nod.at>
> >
> > Maybe a
> >
> > Tested-by: Richard Weinberger <richard@nod.at>
> >
> > ?
> >
> >> Reported-by: Philipp Rosenberger <p.rosenberger@linutronix.de>
> >
> > Should I replace your Reported-by by this one or simply add it?

Philipp deserves the Reported-by. :)

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

Patch 1/3 unbreaks v4.14.x on my board.

Tested-by: Richard Weinberger <richard@nod.at>

Thanks,
//richard