From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932267AbcGYWY7 (ORCPT ); Mon, 25 Jul 2016 18:24:59 -0400 Received: from mail-wm0-f51.google.com ([74.125.82.51]:36776 "EHLO mail-wm0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932163AbcGYWYz (ORCPT ); Mon, 25 Jul 2016 18:24:55 -0400 Subject: Re: [PATCH v3 3/9] media: adv7180: add support for NEWAVMODE To: Steve Longerbeam , Steve Longerbeam , lars@metafoo.de 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: mchehab@kernel.org, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org From: Ian Arkver Message-ID: <153fdfbc-a929-6584-3f06-26413498c1fa@gmail.com> Date: Mon, 25 Jul 2016 23:24:51 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.1.1 MIME-Version: 1.0 In-Reply-To: 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 25/07/16 23:04, Steve Longerbeam wrote: > > > 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 OK, interesting. And weird indeed. I may be interfacing an ADV7280 to the i.MX6 in the August timeframe, depending on project needs etc. I'll see if I hit this with that chip. My test app does use autodetect. Incidentally, looking at the BT656-5 spec and comparing to the tvp5150, I see that the spec calls for 244 and 243 lines per field for NTSC, and the tvp5150 provides that number of lines. However this write... adv7180_write(state, ADV7180_REG_NTSC_V_BIT_END, ADV7180_NTSC_V_BIT_END_MANUAL_NVEND); where NVEND is 0x4f, configures the adv7180 to send only 242 lines in each field. Not sure if this is significant. Regards, IanJ. > >> 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 >> > >