Re: [PATCH 1/4] mtd: spi-nor: move the SPI NOR commands to a new header file

From: Angus Clark <angus.clark@st.com>
To: Huang Shijie <b32955@freescale.com>
Cc: "marex@denx.de" <marex@denx.de>, Angus CLARK <angus.clark@st.com>,
	"broonie@linaro.org" <broonie@linaro.org>,
	"linux-mtd@lists.infradead.org" <linux-mtd@lists.infradead.org>,
	"Gupta, Pekon" <pekon@ti.com>,
	"Poddar, Sourav" <sourav.poddar@ti.com>,
	"computersforpeace@gmail.com" <computersforpeace@gmail.com>,
	"dwmw2@infradead.org" <dwmw2@infradead.org>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH 1/4] mtd: spi-nor: move the SPI NOR commands to a new header file
Date: Tue, 26 Nov 2013 14:48:35 +0000	[thread overview]
Message-ID: <5294B4C3.9080201@st.com> (raw)
In-Reply-To: <52946197.5050104@freescale.com>

On 11/26/2013 08:53 AM, Huang Shijie wrote:
> Hi Pekon:
>> (1)
>> It's better to take all Flash vendor specific opcodes from DT..
> firstly, some arch may does not support the DT, such as x86.

Indeed, although the 'flash_platform_data' structure could be extended to
provide similar functionality, if that were deemed the right way to go.  However...

> 
> second, it makes people crazy if we put the opcodes in the DT :)

I would agree.  Where possible, I think it's preferable for the driver to probe
device properties at runtime.  One benefit, often overlooked, is that it allows
board manufacturers to second-source parts without having to rebuild, and
possibly re-certify, binaries.

>> With new framework we should do away with macros for each vendor,
>> instead let each board file provide this information based on flash
>> device
>> which is mounted on it.
>>
>> (2)
>> And also, I suggest not to touch m25p80 in anyway, bcoz it stable driver
>> used by many. So unless spi-nor framework is accepted and is stable we
>> m25p80 should continue working as it is.
>> Thus your patches should be independent of any existing driver or other
>> frameworks. This way it might get accepted fast. Then later you can
>> provide
>> a way to attach m25p80 to spi-nor framework.
>> Thoughts ?
> the merge window is closed not long ago, and we have rc1 now.
> 
> Isn't it the BEST time to change the m25p80?
> 

The spi-nor framework has great potential, but I think you should allow some
time for other driver developers to comment, and the framework to mature.
Without greater support, it risks becoming another single-use framework.

Cheers,

Angus

> thanks
> Huang Shijie
> 
> 
> 
> ______________________________________________________
> Linux MTD discussion mailing list
> http://lists.infradead.org/mailman/listinfo/linux-mtd/
> 

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