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Date:   Thu, 15 Nov 2018 14:04:00 +0100
From:   Miquel Raynal <miquel.raynal@bootlin.com>
To:     Liang Yang <liang.yang@amlogic.com>
Cc:     Boris Brezillon <boris.brezillon@bootlin.com>,
        Rob Herring <robh@kernel.org>,
        Hanjie Lin <hanjie.lin@amlogic.com>,
        Victor Wan <victor.wan@amlogic.com>,
        Jianxin Pan <jianxin.pan@amlogic.com>,
        Neil Armstrong <narmstrong@baylibre.com>,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        Richard Weinberger <richard@nod.at>,
        Yixun Lan <yixun.lan@amlogic.com>,
        <linux-kernel@vger.kernel.org>,
        Marek Vasut <marek.vasut@gmail.com>,
        Jian Hu <jian.hu@amlogic.com>, <linux-mtd@lists.infradead.org>,
        Kevin Hilman <khilman@baylibre.com>,
        Carlo Caione <carlo@caione.org>,
        <linux-amlogic@lists.infradead.org>,
        Brian Norris <computersforpeace@gmail.com>,
        David Woodhouse <dwmw2@infradead.org>,
        <linux-arm-kernel@lists.infradead.org>,
        Jerome Brunet <jbrunet@baylibre.com>,
        Wolfram Sang <wsa@the-dreams.de>
Subject: Re: [PATCH v6 2/2] mtd: rawnand: meson: add support for Amlogic
 NAND flash controller
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Hi Liang,

Liang Yang <liang.yang@amlogic.com> wrote on Thu, 15 Nov 2018 19:25:07
+0800:

> Hi Boris,
> 
> I have implemented dma access base on these helpers you provided below.
> we prepare to send v7 version now, so when will these helpers be pushed?

Thanks for your work. You can send the v7 so we will have a look at the
overall driver; but since we raised the DMA buffers issue we had a
discussion with Boris about how to handle them and I think we are going
to adopt the same solution as Wolfram in the I2C subsystem: manual
flagging. Sadly, this is probably the best we can do to ensure proper
DMA support.

There is nothing set is stone yet but I started a small rework to
handle MTD operations differently (and add a DMA_SAFE flag), you can
have a look there [1]. Don't base your work on it for now as it is just
a preliminary version, subject to big changes.

[1] https://github.com/miquelraynal/linux/commits/dma-safe-buffers

Thanks,
Miquèl