From mboxrd@z Thu Jan  1 00:00:00 1970
From: Adam Jackson <ajax@redhat.com>
Subject: Re: [radeon] EDID checksum is invalid
Date: Tue, 06 Dec 2011 12:52:41 -0500
Message-ID: <4EDE5669.5070002@redhat.com>
References: <CAA1sL1TzS3bqWJeWu7+HrFJtz+BB1YwU6uwFfxPJyem+qgT3Bg@mail.gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"; Format="flowed"
Content-Transfer-Encoding: 7bit
Return-path: <dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org>
Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28])
	by gabe.freedesktop.org (Postfix) with ESMTP id 362309E874
	for <dri-devel@lists.freedesktop.org>;
	Tue,  6 Dec 2011 11:06:50 -0800 (PST)
In-Reply-To: <CAA1sL1TzS3bqWJeWu7+HrFJtz+BB1YwU6uwFfxPJyem+qgT3Bg@mail.gmail.com>
List-Unsubscribe: <http://lists.freedesktop.org/mailman/options/dri-devel>,
	<mailto:dri-devel-request@lists.freedesktop.org?subject=unsubscribe>
List-Archive: <http://lists.freedesktop.org/archives/dri-devel>
List-Post: <mailto:dri-devel@lists.freedesktop.org>
List-Help: <mailto:dri-devel-request@lists.freedesktop.org?subject=help>
List-Subscribe: <http://lists.freedesktop.org/mailman/listinfo/dri-devel>,
	<mailto:dri-devel-request@lists.freedesktop.org?subject=subscribe>
Sender: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org
Errors-To: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org
To: Alexander Beregalov <a.beregalov@gmail.com>
Cc: dri-devel@lists.freedesktop.org
List-Id: dri-devel@lists.freedesktop.org

On 12/5/11 3:39 PM, Alexander Beregalov wrote:

> At boot time:
> [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 206
>   Raw EDID:
>          27 0f 01 03 80 26 1e 78 2a de 95 a3 54 4c 99 26
>          0f 50 54 bf ef 80 81 80 81 40 71 4f 01 01 01 01
>          01 01 01 01 01 01 30 2a 00 98 51 00 2a 40 30 70
>          13 00 78 2d 11 00 00 1e 00 00 00 fd 00 38 4b 1e
>          51 0e 00 0a 20 20 20 20 20 20 00 00 00 fc 00 53
>          79 6e 63 4d 61 73 74 65 72 0a 20 20 00 00 00 ff
>          00 48 53 47 59 39 30 37 30 33 32 0a 20 20 00 59
>          ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

This looks like an EDID fetch of bytes 16 through 143, instead of 0 
through 127 (ie, skip the first 16, last 16 filled with -1).

> Few days after that:
> [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 38
>   Raw EDID:
>          30 2a 00 98 51 00 2a 40 30 70 13 00 78 2d 11 00
>          00 1e 00 00 00 fd 00 38 4b 1e 51 0e 00 0a 20 20
>          20 20 20 20 00 00 00 fc 00 53 79 6e 63 4d 61 73
>          74 65 72 0a 20 20 00 00 00 ff 00 48 53 47 59 39
>          30 37 30 33 32 0a 20 20 00 59 ff ff ff ff ff ff
>          ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>          ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>          ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

Offset of 54 bytes here, which is weirder.

Possibly the i2c code isn't resetting the index to 0 when it needs to.

- ajax