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From:   Janusz Krzysztofik <jmkrzyszt@gmail.com>
To:     Boris Brezillon <boris.brezillon@bootlin.com>
Cc:     Linus Walleij <linus.walleij@linaro.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        David Woodhouse <dwmw2@infradead.org>,
        Brian Norris <computersforpeace@gmail.com>,
        Marek Vasut <marek.vasut@gmail.com>,
        Tony Lindgren <tony@atomide.com>,
        Aaro Koskinen <aaro.koskinen@iki.fi>,
        linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org,
        linux-mtd@lists.infradead.org, linux-doc@vger.kernel.org,
        linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org,
        Janusz Krzysztofik <jmkrzyszt@gmail.com>
Subject: Re: [RFC PATCH v2 05/12] mtd: rawnand: ams-delta: use GPIO API for data read/write
Date:   Tue, 07 Aug 2018 19:11:22 +0200
Message-ID: <1593487.Cmi0mten1c@z50>
In-Reply-To: <20180807190627.4340aade@bbrezillon>
References: <20180718235710.18242-1-jmkrzyszt@gmail.com> <20180806222918.12644-6-jmkrzyszt@gmail.com> <20180807190627.4340aade@bbrezillon>
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Hi Boris,

On Tuesday, August 7, 2018 7:06:27 PM CEST Boris Brezillon wrote:
> On Tue,  7 Aug 2018 00:29:11 +0200
> Janusz Krzysztofik <jmkrzyszt@gmail.com> wrote:
> 
> > Don't readw()/writew() data directly from/to GPIO port which is under
> > control of gpio-omap driver, use GPIO API instead.
> > 
> > Degrade of performance on Amstrad Delta is completely not acceptable.
> 
> Can we have numbers along with information about where the overhead is
> when using gpiod_{get,set}_raw_array_value()?

Yes, as soon as I get physical access to the device, probably this or next 
weekend.

Thanks,
Janusz