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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C8F77C433EF for ; Sun, 20 Feb 2022 13:35:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243433AbiBTNf2 (ORCPT ); Sun, 20 Feb 2022 08:35:28 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:48546 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230222AbiBTNf1 (ORCPT ); Sun, 20 Feb 2022 08:35:27 -0500 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D509D5372F for ; Sun, 20 Feb 2022 05:35:06 -0800 (PST) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 1240E25B; Sun, 20 Feb 2022 14:35:05 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1645364105; bh=0ymc4nhOToJLaeevubO3Hwei82MBSqdI66KaNXgGV/U=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=EAkFA3n3vgaTcLjJKQ3OK1NZrt22xmFFkV/iwyHFFmQZpkK+RmtTok7xNDaKpEXGZ qGm10BS6Sp9oYi6+bUmM4TMPau7/7KYdDxjd1dHSZLM1AuwDzCLDmfe+MrgjmSg+dq O5dSt2pcQn3riOWgii+oCgwSx7wGD2TfqGVISIes= Date: Sun, 20 Feb 2022 15:34:55 +0200 From: Laurent Pinchart To: Jacopo Mondi Cc: slongerbeam@gmail.com, p.zabel@pengutronix.de, shawnguo@kernel.org, s.hauer@pengutronix.de, festevam@gmail.com, mchehab@kernel.org, hverkuil-cisco@xs4all.nl, martin.kepplinger@puri.sm, rmfrfs@gmail.com, xavier.roumegue@oss.nxp.com, alexander.stein@ew.tq-group.com, dorota.czaplejewicz@puri.sm, kernel@pengutronix.de, linux-imx@nxp.com, linux-media@vger.kernel.org, linux-staging@lists.linux.dev, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 5/8] staging: media: imx: Use DUAL pixel mode if available Message-ID: References: <20220214184318.409208-1-jacopo@jmondi.org> <20220214184318.409208-6-jacopo@jmondi.org> <20220215085918.dxilh2sx2yx2l6c5@uno.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220215085918.dxilh2sx2yx2l6c5@uno.localdomain> Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi Jacopo, On Tue, Feb 15, 2022 at 09:59:18AM +0100, Jacopo Mondi wrote: > On Tue, Feb 15, 2022 at 09:12:44AM +0200, Laurent Pinchart wrote: > > On Mon, Feb 14, 2022 at 07:43:15PM +0100, Jacopo Mondi wrote: > > > The pixel sampling mode controls the size of data sampled from the CSI > > > Rx queue. The supported sample size depends on the configuration of the > > > preceding block in the capture pipeline and is then dependent on the SoC > > > version the CSI peripheral is integrated on. > > > > > > When capturing YUV422 data if dual sample mode is available use it. > > > > > > This change is particularly relevant for the IMX8MM SoC which uses the > > > CSIS CSI-2 receiver which operates in dual pixel mode. > > > > > > Other SoCs should be unaffected by this change and should continue to > > > operate as before. > > > > > > Signed-off-by: Xavier Roumegue > > > Signed-off-by: Jacopo Mondi > > > --- > > > drivers/staging/media/imx/imx7-media-csi.c | 10 +++++++++- > > > 1 file changed, 9 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/staging/media/imx/imx7-media-csi.c b/drivers/staging/media/imx/imx7-media-csi.c > > > index 112096774961..a8bdfb0bb0ee 100644 > > > --- a/drivers/staging/media/imx/imx7-media-csi.c > > > +++ b/drivers/staging/media/imx/imx7-media-csi.c > > > @@ -426,6 +426,7 @@ static void imx7_csi_configure(struct imx7_csi *csi) > > > { > > > struct imx_media_video_dev *vdev = csi->vdev; > > > struct v4l2_pix_format *out_pix = &vdev->fmt; > > > + struct imx_media_dev *imxmd = csi->imxmd; > > > int width = out_pix->width; > > > u32 stride = 0; > > > u32 cr3 = BIT_FRMCNT_RST; > > > @@ -436,7 +437,7 @@ static void imx7_csi_configure(struct imx7_csi *csi) > > > cr18 &= ~(BIT_CSI_HW_ENABLE | BIT_MIPI_DATA_FORMAT_MASK | > > > BIT_DATA_FROM_MIPI | BIT_BASEADDR_CHG_ERR_EN | > > > BIT_BASEADDR_SWITCH_EN | BIT_BASEADDR_SWITCH_SEL | > > > - BIT_DEINTERLACE_EN); > > > + BIT_DEINTERLACE_EN | BIT_MIPI_DOUBLE_CMPNT); > > > > > > if (out_pix->field == V4L2_FIELD_INTERLACED) { > > > cr18 |= BIT_DEINTERLACE_EN; > > > @@ -500,6 +501,13 @@ static void imx7_csi_configure(struct imx7_csi *csi) > > > case MEDIA_BUS_FMT_YUYV8_2X8: > > > case MEDIA_BUS_FMT_YUYV8_1X16: > > > cr18 |= BIT_MIPI_DATA_FORMAT_YUV422_8B; > > > + > > > + /* If dual mode is supported use it. */ > > > + if (imxmd->info->sample_modes & MODE_DUAL) { > > > + cr18 |= BIT_MIPI_DOUBLE_CMPNT; > > > + cr3 |= BIT_TWO_8BIT_SENSOR; > > > + } > > > > I would implement this differently: > > > > case MEDIA_BUS_FMT_UYVY8_2X8: > > case MEDIA_BUS_FMT_YUYV8_2X8: > > cr18 |= BIT_MIPI_DATA_FORMAT_YUV422_8B; > > break; > > > > case MEDIA_BUS_FMT_UYVY8_1X16: > > case MEDIA_BUS_FMT_YUYV8_1X16: > > cr3 |= BIT_TWO_8BIT_SENSOR; > > cr18 |= BIT_MIPI_DATA_FORMAT_YUV422_8B > > | BIT_MIPI_DOUBLE_CMPNT; > > break; > > > > This would support either option here. What you will then need to change > > is imx7_csi_enum_mbus_code() and imx7_csi_try_fmt(), to allow/disallow > > the 2X8 and 1X16 variants based on the SoC. This is important for the > > Exactly. And being the format list in the shared helper I decided it > was really not worth adding any SoC specific code to those helpers > which should ideally be nuked. > > Should we decouple the helpers to get to a point where we can have > SoC-specific formats list ? Then I would be more than happy to use the > above construct. Yes, we should. I have started working on this, but haven't had time to complete the work yet. > There is one quirk I'm not sure about: How does the CSI connect to the > transmitter ? It is my undertanding that in i.MX8 connects to the the > CSI-2 receiver (either CSIS or the Northwest tech one). Does in older > SoC revisions connects directly to a parallel sensor ? On i.MX7 there's a mux that allows selecting the CSI-2 receiver or the parallel input. It's implemented using the video-mux driver, see imx7s.dtsi for details. > I'm asking also because there is a comment that reports > > /* > * CSI-2 sources are supposed to use the 1X16 formats, but not > * all of them comply. Support both variants. > */ > > But if the preceding block is the CSI-2 receiver, we control what > formats it exposes and we can use both 2X8 or 1X16 depending on the > SoC specificities and we don't care about the CSI-2 Tx supported > formats. Does that comment make sense in your opinion ? I think the comment should be dropped. There are CSI-2 sensor drivers that incorrectly use the 2X8 formats instead of 1X16, but I don't think we should work around that here, the sensor drivers should be fixed instead. > Also be aware that, in example, if we expose from the CSIS source pad > both 2X8 and 1X16 we create a condition where userspace could > configure the pipeline uncorrectly. > > Let's draw a table (for i.MX8 only as I don't know about the 7) > > > 8MM/CSI 8MQ/CSI 8MP/ISI > CSIS Dual Dual > NW Single > > > Each block would then support > > CSIS Dual > NW Single > CSI Dual/Single > ISI Dual > > So we create a potential for a misconfiguration in 8MM with > > CSIS = Dual > CSI = Single > > or for the 8MQ > > NW = Single > CSI = Double > > If we don't create a list of SoC specific formats. Nothing bad, -EPIPE > will be returned, but maybe we should avoid that ? Format propagation is typically done from source to sink in userspace, so the risk of picking an incorrect format is very low (and it would be a userspace bug in any case). Nonetheless, it would be nice to avoid exposing formats that can't be used, but that can be done later. > > i.MX7, which has both a CSI-2 input and a parallel input. When using the > > CSIS it can (and should) use double component mode, while when using the > > parallel input it can work in 8-bit or 16-bit mode depending on how the > > sensor is wired. > > I didn't know i.MX7 used the CSIS :/ > Ah wait, the driver was called imx7-mipi-csi2 :/ :-) > > > + > > > break; > > > } > > > } -- Regards, Laurent Pinchart