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From: Chris Wilson <chris@chris-wilson.co.uk>
To: David Flynn <davidf@rd.bbc.co.uk>,
	dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH] drm/i915/dp: Fix I2C/EDID handling with active DisplayPort to DVI converter
Date: Wed, 08 Dec 2010 20:17:12 +0000	[thread overview]
Message-ID: <849307$amb8jq@azsmga001.ch.intel.com> (raw)
In-Reply-To: <20101208161021.GF20844@rd.bbc.co.uk>

On Wed, 8 Dec 2010 16:10:21 +0000, David Flynn <davidf@rd.bbc.co.uk> wrote:
> The DisplayPort standard (1.1a) states that:
>   The I2C-over-AUX Reply field is valid only when Native AUX CH Reply
>   field is AUX_ACK (00). When Native AUX CH Reply field is not 00, then,
>   I2C-over-AUX Reply field must be 00 and be ignored.
> 
> This fixes broken EDID reading when using an active DisplayPort to
> duallink DVI converter.  If the AUX CH replier chooses to defer the
> transaction, a short read occurs and erroneous data is returned as
> the i2c reply due to a lack of length checking and failure to check
> for AUX ACK.

And it didn't break my bog standard DP setup. :)
Applied to -fixes and tagged for stable.

Thanks,
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre

  reply	other threads:[~2010-12-08 20:17 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-12-08 16:10 [PATCH] drm/i915/dp: Fix I2C/EDID handling with active DisplayPort to DVI converter David Flynn
2010-12-08 20:17 ` Chris Wilson [this message]
2010-12-09 18:31   ` David Flynn

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