Re: [PATCH v2 0/5] mtd: spi-nor: Add support for Octal 8D-8D-8D mode

From: masonccyang@mxic.com.tw
To: "Boris Brezillon" <boris.brezillon@collabora.com>
Cc: broonie@kernel.org, juliensu@mxic.com.tw,
	linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org,
	linux-spi@vger.kernel.org,
	"Pratyush Yadav" <me@yadavpratyush.com>,
	miquel.raynal@bootlin.com, "Pratyush Yadav" <p.yadav@ti.com>,
	richard@nod.at, tudor.ambarus@microchip.com, vigneshr@ti.com
Subject: Re: [PATCH v2 0/5] mtd: spi-nor: Add support for Octal 8D-8D-8D mode
Date: Wed, 29 Apr 2020 13:59:36 +0800	[thread overview]
Message-ID: <OFC28C41CE.C7A0DF28-ON48258559.00209CD2-48258559.0020EC27@mxic.com.tw> (raw)
In-Reply-To: <20200428083423.4fafd187@collabora.com>

Hi Boris,

> > > > On Tue, 21 Apr 2020 14:39:42 +0800
> > > > Mason Yang <masonccyang@mxic.com.tw> wrote:
> > > > 
> > > > > Hello,
> > > > > 
> > > > > This is repost of patchset from Boris Brezillon's
> > > > > [RFC,00/18] mtd: spi-nor: Proposal for 8-8-8 mode support [1]. 
> > > > 
> > > > I only quickly went through the patches you sent and saying it's a
> > > > repost of the RFC is a bit of a lie. You completely ignored the 
state
> > > > tracking I was trying to do to avoid leaving the flash in 8D mode 
when
> > > > suspending/resetting the board, and I think that part is crucial. 
If I
> > > > remember correctly, we already had this discussion so I must say 
I'm a
> > > > bit disappointed.
> > > > 
> > > > Can you sync with Pratyush? I think his series [1] is better in 
that 
> > it
> > > > tries to restore the flash in single-SPI mode before suspend (it's
> > > > missing the shutdown case, but that can be easily added I think). 
Of
> > > > course that'd be even better to have proper state tracking at the 
SPI
> > > > NOR level. 
> > > 
> > > Hi Mason,
> > > 
> > > I posted a re-roll of my series here [0]. Could you please base your 

> > > changes on top of it? Let me know if the series is missing something 
you 
> > 
> > > need.
> > > 
> > > [0] 
> > 
https://lore.kernel.org/linux-mtd/20200424184410.8578-1-p.yadav@ti.com/
> > 
> > 
> > Our mx25uw51245g supports BFPT DWORD-18,19 and 20 data and xSPI 
profile 
> > 1.0,
> > and it comply with BFPT DWORD-19, octal mode enable sequences by write 
CFG 
> > Reg2 
> > with instruction 0x72. Therefore, I can't apply your patches.
> > 
> > I quickly went through your patches but can't reply them in each your 
> > patches.
> 
> Why?!! Aren't you registered to the MTD mailing list? Sorry but having
> reviews outside of the original thread is far from ideal. Please find a
> way to reply to the original patchset.
> 
> > 
> > i.e,.
> > 1) [v4,03/16] spi: spi-mem: allow specifying a command's extension
> > 
> > -                                u8 opcode;
> > +                                u16 opcode;
> > 
> > big/little Endian issue, right?
> 
> There's no endianness issue since it's SPI controller responsibility to
> interpret this field.
> 
> > why not just u8 ext_opcode;
> 
> Because I see the ext_ext_code comimg, and it's also more consistent
> with the addr field if we use an u16 and a number of cmd cycles.
> 
> > No any impact for exist code and actually only xSPI device use 
extension 
> > command.
> 
> And extending the opcode field to an u16 has no impact either.
> 

okay, got your point.

thanks for your time & comments.
Mason

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