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From: Fabio Estevam <festevam@gmail.com>
Date: Sat, 7 Jan 2017 19:43:48 -0200
Message-ID: <CAOMZO5D00YFLS=pddAqPo_FUoP6MF-juAef2H71-Wx_NQArdpw@mail.gmail.com>
Subject: Re: imx: RS-485 problems during TX, maybe DMA related
To: Clemens Gruber <clemens.gruber@pqgruber.com>
Cc: "linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        =?UTF-8?Q?Uwe_Kleine=2DK=C3=B6nig?= 
        <u.kleine-koenig@pengutronix.de>,
        Nandor Han <nandor.han@ge.com>, Lucas Stach <l.stach@pengutronix.de>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        linux-kernel <linux-kernel@vger.kernel.org>
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Hi Clemens,

On Sat, Jan 7, 2017 at 6:59 PM, Clemens Gruber
<clemens.gruber@pqgruber.com> wrote:

> Great!
>
> Did you observe the same effect I described, with the doubling of
> characters in the front and the leftovers from previous transmissions at
> the end?

No, I don't observe these errors when I use 'rts-gpios' in the device tree.

Maybe you could try to use 'rts-gpios' for a quick test by applying
the patches I have just sent.

If you run this test, please remove 'uart-has-rtscts' from your dts.
According to Documentation/devicetree/bindings/serial/serial.txt they
are mutually-exclusive.

Regards,

Fabio Estevam