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Date: Thu, 20 Mar 2014 14:02:39 -0400
From: Santosh Shilimkar <santosh.shilimkar@ti.com>
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To: Warner Losh <imp@bsdimp.com>
CC: Brian Norris <computersforpeace@gmail.com>,
        Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>,
        David Woodhouse <dwmw2@infradead.org>, <galak@codeaurora.org>,
        <robh+dt@kernel.org>, <pawel.moll@arm.com>, <mark.rutland@arm.com>,
        <ijc+devicetree@hellion.org.uk>, <rob@landley.net>,
        Russell King - ARM Linux <linux@arm.linux.org.uk>,
        <grygorii.strashko@ti.com>, <devicetree@vger.kernel.org>,
        <linux-doc@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-mtd@lists.infradead.org>,
        Murali Karicheri <m-karicheri2@ti.com>
Subject: Re: [PATCH 2/3] mtd: davinci-nand: add dts property for NAND_NO_SUBPAGE_WRITE
 option
References: <1395335184-4745-1-git-send-email-ivan.khoronzhuk@ti.com> <1395335184-4745-3-git-send-email-ivan.khoronzhuk@ti.com> <532B2183.2080309@ti.com> <20140320172912.GW31517@norris-Latitude-E6410> <532B2766.6090506@ti.com> <D69011BE-C37F-4085-B992-45F6F32AF1D0@gmail.com>
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On Thursday 20 March 2014 01:44 PM, Warner Losh wrote:
> 
> On Mar 20, 2014, at 11:37 AM, Santosh Shilimkar <santosh.shilimkar@ti.com> wrote:
> 
>>
>>
>> On Thursday 20 March 2014 01:29 PM, Brian Norris wrote:
>>> On Thu, Mar 20, 2014 at 01:12:35PM -0400, Santosh Shilimkar wrote:
>>>> Boris,
>>>
>>> Who's Boris? And why should Boris be taking this patch? It's an MTD
>>> patch.
>>>
>> I got your name completely wrong. Sorry....
>>
>>>> On Thursday 20 March 2014 01:06 PM, Ivan Khoronzhuk wrote:
>>>>> From: Murali Karicheri <m-karicheri2@ti.com>
>>>>>
>>>>> After testing NAND flash with ubifs for k2hk-emv board were committed
>>>>> that flash doesn't support subpage writing, so we can fix it by
>>>>> adding a property to disable subpage write.
>>>
>>> What flash? We try to autodetect NAND as much as possible. Perhaps we
>>> should be adding infrastructure support instead of hacking it with a DT
>>> property.
>>>
>> We can't auto detect it and thats why the DT approach was taken. We
>> will double check that.
> 
> I though sub page writing was one of the fields in the onfi and/or jedec(toggle) meta data structures. Have you looked there?
> 
Am not sure if I follow you. The limitation is from the TI NAND controller(AEMIF) and
not the NAND memory. 

regards,
Santosh