From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756311AbcGYWEZ (ORCPT ); Mon, 25 Jul 2016 18:04:25 -0400 Received: from relay1.mentorg.com ([192.94.38.131]:42431 "EHLO relay1.mentorg.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755381AbcGYWEG (ORCPT ); Mon, 25 Jul 2016 18:04:06 -0400 Subject: Re: [PATCH v3 3/9] media: adv7180: add support for NEWAVMODE To: Ian Arkver , Steve Longerbeam , References: <1469293249-6774-1-git-send-email-steve_longerbeam@mentor.com> <1469293249-6774-4-git-send-email-steve_longerbeam@mentor.com> <0fa0100f-3c7a-9dc0-2b29-7de9da7e86b5@mentor.com> <67a21914-cf3d-7d80-7b80-6abfd26c1a21@gmail.com> CC: , , From: Steve Longerbeam Message-ID: Date: Mon, 25 Jul 2016 15:04:02 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <67a21914-cf3d-7d80-7b80-6abfd26c1a21@gmail.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/25/2016 12:36 PM, Ian Arkver wrote: > On 25/07/16 18:55, Steve Longerbeam wrote: >> On 07/25/2016 05:04 AM, Ian Arkver wrote: >>> On 23/07/16 18:00, Steve Longerbeam wrote: >>>> >>>> +#define ADV7180_VSYNC_FIELD_CTL_1_NEWAVMODE 0x02 >>> See below re this value. >>> >> Hi Ian, I double-checked the ADV7180 datasheet, this value is >> correct. Bit 4, when cleared, _enables_ NEWAVMODE. > > Hah, ok. I'm not familiar enough with the history of this chip and didn't > know what "OLDAVMODE" was. So, to enable NEWAVMODE you clear > the NEWAVMODE bit. That makes perfect sense. > > Anyway, I still don't see what NEWAVMODE gets you. Hi Ian, With video standard auto-detect disabled in the chip (VID_SEL > 2), captured NTSC images by the i.mx6q SabreAuto are corrupted, best I can describe it as "extremely fuzzy". Only when newavmode is enabled do the images look good again, in manual mode. With auto-detect enabled, images look good with or without newavmode. The strange this is, the auto-detected standard is identical to the standard set explicitly in manual mode (NTSC-M). I did a complete i2c dump of the registers for both auto-detect and manual mode, and found no other differences besides the auto-detect/manual setting. Trying to track this down further would probably require a logic analyzer on the bt.656 bus, which I don't have access to. I will not be debugging this further so NEWAVMODE it will have to remain. Steve > As > far as I can see it just locks down the timings and removes the > flexibility > the chip otherwise offers to move the BT656 SAV and EAV codes around > relative to the incoming video. > > In what circumstances would you need to set the newavmode property > and change this default behaviour? We're not coupling the adv7180 > back-to-back with an ADV video encoder here, which is what > NEWAVMODE is for and is presumably why AD recommend it for their > eval boards. We're trying to get a BT656 compliant stream, which is > what the default mode purports to generate. > > Regards, > IanJ >