From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 18A66C432C0 for ; Thu, 28 Nov 2019 04:14:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E1F7D21569 for ; Thu, 28 Nov 2019 04:14:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727446AbfK1EOz convert rfc822-to-8bit (ORCPT ); Wed, 27 Nov 2019 23:14:55 -0500 Received: from mail-ed1-f65.google.com ([209.85.208.65]:39711 "EHLO mail-ed1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727113AbfK1EOz (ORCPT ); Wed, 27 Nov 2019 23:14:55 -0500 Received: by mail-ed1-f65.google.com with SMTP id n26so21564073edw.6; Wed, 27 Nov 2019 20:14:53 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:content-transfer-encoding; bh=5sfODevhRJ0fpp4KUyFGDUEZZ6v0++XmlIguNOG57fk=; b=SdqudRZtiXntSWYVjsD+M3Dff6R0g1PA7mcqkadkbRKalHsT8/eRvK4wI1B+RCgmjw MwB8CwNpJWCH9/pWViP2rcByUVhQkZDYcxD5hPl6e6zUw5GDw2GZrWc5ApyB0jXsVLK+ bGt9a5YvkD8Wf1Mix9OEkwN9DNlgGSgvOLIOqwe9vJINEmTrBfq8ELTmhi1vkpBQL831 KTcBY20yeUwQ7LX2Rmngsf96YK5YumNBeSBDcwJQ/s5NdZjPzVkVf0yflmR+e/i+K5eU HsSsltFgQhrTePmFNmiKtFkNzp+fcMhYBx4ICsXr7sAAbvCqYXHlIBURPFNbxME6cDOU LCqg== X-Gm-Message-State: APjAAAVJOGM/4NE0Pv6zN7mHKRnK3oYNjz4YxEpx12sWRhqlJWCpYzN1 9WvGsCPX8L3QLvRWcZCY0qmtUzqf+8s= X-Google-Smtp-Source: APXvYqzgFhD+T5fxUoya/jLtBL4eHuSsChCKXqhcBOGldyYTNxMyiPTKT3ULF356xWVfVgIUv7oYwA== X-Received: by 2002:a17:906:31c3:: with SMTP id f3mr30077832ejf.198.1574914491795; Wed, 27 Nov 2019 20:14:51 -0800 (PST) Received: from mail-wr1-f51.google.com (mail-wr1-f51.google.com. [209.85.221.51]) by smtp.gmail.com with ESMTPSA id z69sm907335ede.88.2019.11.27.20.14.51 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 27 Nov 2019 20:14:51 -0800 (PST) Received: by mail-wr1-f51.google.com with SMTP id a15so29341678wrf.9; Wed, 27 Nov 2019 20:14:51 -0800 (PST) X-Received: by 2002:adf:81e3:: with SMTP id 90mr2263793wra.23.1574914490971; Wed, 27 Nov 2019 20:14:50 -0800 (PST) MIME-Version: 1.0 References: <20191128020259.1338188-1-megous@megous.com> <20191128102608.035cbb996c8681a6fb035336@magewell.com> <20191128030653.5fhcolvib6tzf4zc@core.my.home> <20191128035056.77554jav3eo6h7su@core.my.home> In-Reply-To: <20191128035056.77554jav3eo6h7su@core.my.home> From: Chen-Yu Tsai Date: Thu, 28 Nov 2019 12:14:35 +0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [linux-sunxi] [PATCH] media: sun6i-csi: Fix incorrect HSYNC/VSYNC/PCLK polarity configuration To: =?UTF-8?Q?Ond=C5=99ej_Jirman?= , Chen-Yu Tsai , Yong , linux-sunxi , Mauro Carvalho Chehab , Maxime Ripard , "open list:CSI DRIVERS FOR ALLWINNER V3s" , "moderated list:ARM/Allwinner sunXi SoC support" , open list Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 28, 2019 at 11:51 AM Ondřej Jirman wrote: > > On Thu, Nov 28, 2019 at 11:26:24AM +0800, Chen-Yu Tsai wrote: > > On Thu, Nov 28, 2019 at 11:06 AM Ondřej Jirman wrote: > > > > > > Hi, > > > > > > On Thu, Nov 28, 2019 at 10:26:08AM +0800, Yong wrote: > > > > Hi Ondrej, > > > > > > > > This has been discussed. > > > > And Maxime sent a patch for this: > > > > https://www.mail-archive.com/linux-media@vger.kernel.org/msg127149.html > > > > > > Thanks for pointing to the previous patch. But that patch doesn't make any > > > sense, and breaks things for me, and doesn't even match BSP code, which > > > has no such reversal, and works fine with about 30 cam drivers. > > > > > > Also how do you explain my findings? > > > > > > My camera is sending correct signals, verified by looking at them actually (see > > > below), and CSI is not receiving the image. I have to flip HSYNC/VSYNC to be > > > oposite of that what CSI driver expects and I get a noisy image and if I fix > > > PCLK polarity too, the noise goes away, which means now I'm also sampling when > > > the data are stable and not when they're changing. > > > > > > Here: (output from my cam, that I configured to have VSYNC ACTIVE LOW, HSYNC > > > ACTIVE LOW) And the signal is clearly that, as you can see yourself: > > > > > > https://megous.com/dl/tmp/98df81b7ed0126ec.png > > > > From the looks of things you have active-high VSYNC with active-low HREF. > > HREF is not the same as HSYNC, in fact quite the opposite. V/H SYNC are > > pulses, active only when there should be no data and the line/frame switch > > happens, while V/H REF are held active when there is data. I personally > > find these terms very confusing. :( > > > > Now the timing diagrams in the Allwinner manuals would suggest that when > > they are talking about H/V SYNC, they are actually referring to H/V REF. > > The HSYNC line is high/active when there is valid data, and the VSYNC line > > is high/active for the duration of the frame. > > > > I think both sides need to be checked that they are using the correct > > polarity, and maybe also have the media maintainers clarify how the > > polarity should be interpreted when the hardware uses H/V ref instead > > of H/V sync. > > Oh my, so it's just a terminology issue? :) > > This probably should be docummented somewhere. I just thought xSYNC_ACTIVE_HIGH > meant the respective signals are supposed to be HIGH during active phase of data > transmission: that is VSYNC HIGH during entire frame, and HSYNC high during row. Unfortunately I'm having a hard time finding a definitive source for this. My rationale is that since the sync signal is a pulse, the active part would refer to the pulsing part, not the at rest part. > DT bindings documentation doesn't help much either. Yeah. I think this should be sorted out for the whole subsystem, as this not only affects platform drivers, but the sensor drivers as well. > And obviously manufacturers are confused too. > > https://megous.com/dl/tmp/fae07dfb4897bbb3.png It seems at least OmniVision uses VSYNC + HREF. GalaxyCore seems to use VSYNC + HREF as well, but they call it HSYNC, and VSYNC polarity is inverted. :( The OV7670 sensor I was testing had an option to switch from HREF to HSYNC, and another one to invert HREF. Talk about confusing. And HSYNC != inverted HREF. They will be some PCLK cycles apart. > HSYNC/VSYNC "low valid" produces what you see on the previous signal capture > I posted. ;) Thanks. I don't have a scope or logic analyzer. I'll wait for the people who do to figure this out. Regards ChenYu > regards, > o. > > > > > ChenYu > > > > > The above signals are received with CSI driver configured with > > > V4L2_MBUS_VSYNC_ACTIVE_HIGH V4L2_MBUS_HSYNC_ACTIVE_HIGH. So CSI driver is > > > clearly wrong. > > > > > > I think this is pretty clear the driver is buggy. At least for A83T SoC. > > > > > > I'm not sure what Maxime found out, but he should probably re-check his > > > findings. Maxime, can you comment on this? > > > > > > regards, > > > o. > > > > > > > On Thu, 28 Nov 2019 03:02:59 +0100 > > > > Ondrej Jirman wrote: > > > > > > > > > This was discovered by writing a new camera driver and wondering, why > > > > > hsync/vsync polarity setting behaves in reverse to what would be > > > > > expected. Verified by looking at the actual signals and the SoC > > > > > user manual. > > > > > > > > > > Fixes: 5cc7522d8965 ("media: sun6i: Add support for Allwinner CSI V3s") > > > > > Signed-off-by: Ondrej Jirman > > > > > --- > > > > > drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c | 6 +++--- > > > > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > > > > > > > diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c > > > > > index f17e5550602d..98bbcca59a90 100644 > > > > > --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c > > > > > +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c > > > > > @@ -417,12 +417,12 @@ static void sun6i_csi_setup_bus(struct sun6i_csi_dev *sdev) > > > > > if (flags & V4L2_MBUS_FIELD_EVEN_LOW) > > > > > cfg |= CSI_IF_CFG_FIELD_POSITIVE; > > > > > > > > > > - if (flags & V4L2_MBUS_VSYNC_ACTIVE_LOW) > > > > > + if (flags & V4L2_MBUS_VSYNC_ACTIVE_HIGH) > > > > > cfg |= CSI_IF_CFG_VREF_POL_POSITIVE; > > > > > - if (flags & V4L2_MBUS_HSYNC_ACTIVE_LOW) > > > > > + if (flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH) > > > > > cfg |= CSI_IF_CFG_HREF_POL_POSITIVE; > > > > > > > > > > - if (flags & V4L2_MBUS_PCLK_SAMPLE_RISING) > > > > > + if (flags & V4L2_MBUS_PCLK_SAMPLE_FALLING) > > > > > cfg |= CSI_IF_CFG_CLK_POL_FALLING_EDGE; > > > > > break; > > > > > case V4L2_MBUS_BT656: > > > > > -- > > > > > 2.24.0 > > > > > > > > > > -- > > > > > You received this message because you are subscribed to the Google Groups "linux-sunxi" group. > > > > > To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi+unsubscribe@googlegroups.com. > > > > > To view this discussion on the web, visit https://groups.google.com/d/msgid/linux-sunxi/20191128020259.1338188-1-megous%40megous.com. > > > > > > > > > > > > Thanks, > > > > Yong > > > > > > -- > > > You received this message because you are subscribed to the Google Groups "linux-sunxi" group. > > > To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi+unsubscribe@googlegroups.com. > > > To view this discussion on the web, visit https://groups.google.com/d/msgid/linux-sunxi/20191128030653.5fhcolvib6tzf4zc%40core.my.home. > > -- > You received this message because you are subscribed to the Google Groups "linux-sunxi" group. > To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi+unsubscribe@googlegroups.com. > To view this discussion on the web, visit https://groups.google.com/d/msgid/linux-sunxi/20191128035056.77554jav3eo6h7su%40core.my.home.