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Subject: Re: [PATCH v2 08/15] drm/bridge: tc358767: Increase AUX transfer
 length limit
To:     Andrey Smirnov <andrew.smirnov@gmail.com>,
        <dri-devel@lists.freedesktop.org>
CC:     Archit Taneja <architt@codeaurora.org>,
        Andrzej Hajda <a.hajda@samsung.com>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
        Andrey Gusakov <andrey.gusakov@cogentembedded.com>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Chris Healy <cphealy@gmail.com>,
        Lucas Stach <l.stach@pengutronix.de>,
        <linux-kernel@vger.kernel.org>
References: <20190322032901.12045-1-andrew.smirnov@gmail.com>
 <20190322032901.12045-9-andrew.smirnov@gmail.com>
From:   Tomi Valkeinen <tomi.valkeinen@ti.com>
Message-ID: <7dbccf61-29fb-a6df-7f54-fd7c29bba57f@ti.com>
Date:   Fri, 22 Mar 2019 15:14:41 +0200
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On 22/03/2019 05:28, Andrey Smirnov wrote:
> According to the datasheet tc358767 can transfer up to 16 bytes via
> its AUX channel, so the artificial limit of 8 apperas to be too
> low. However only up to 15-bytes seem to be actually supported and
> trying to use 16-byte transfers results in transfers failing
> sporadically (with bogus status in case of I2C transfers), so limit it
> to 15.

16 is the limit from the DP spec. I agree, 8 looks odd.

15 looks odd too, so I think it warrants a comment there in the code.

Does 15 byte transfers ever work? Or mostly works but sometimes fails?

 Tomi

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