From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pg0-f68.google.com ([74.125.83.68]:33280 "EHLO mail-pg0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750827AbdBTW4U (ORCPT ); Mon, 20 Feb 2017 17:56:20 -0500 Subject: Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and getting of frame rates To: Sakari Ailus References: <1487211578-11360-1-git-send-email-steve_longerbeam@mentor.com> <1487211578-11360-30-git-send-email-steve_longerbeam@mentor.com> <20170220220409.GX16975@valkosipuli.retiisi.org.uk> Cc: robh+dt@kernel.org, mark.rutland@arm.com, shawnguo@kernel.org, kernel@pengutronix.de, fabio.estevam@nxp.com, linux@armlinux.org.uk, mchehab@kernel.org, hverkuil@xs4all.nl, nick@shmanahar.org, markus.heiser@darmarIT.de, p.zabel@pengutronix.de, laurent.pinchart+renesas@ideasonboard.com, bparrot@ti.com, geert@linux-m68k.org, arnd@arndb.de, sudipm.mukherjee@gmail.com, minghsiu.tsai@mediatek.com, tiffany.lin@mediatek.com, jean-christophe.trotin@st.com, horms+renesas@verge.net.au, niklas.soderlund+renesas@ragnatech.se, robert.jarzmik@free.fr, songjun.wu@microchip.com, andrew-ct.chen@mediatek.com, gregkh@linuxfoundation.org, shuah@kernel.org, sakari.ailus@linux.intel.com, pavel@ucw.cz, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org, devel@driverdev.osuosl.org, Russell King , Steve Longerbeam From: Steve Longerbeam Message-ID: <6892fb15-2d18-4898-c328-3acff9d6cc39@gmail.com> Date: Mon, 20 Feb 2017 14:56:15 -0800 MIME-Version: 1.0 In-Reply-To: <20170220220409.GX16975@valkosipuli.retiisi.org.uk> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 02/20/2017 02:04 PM, Sakari Ailus wrote: > Hi Steve, > > On Wed, Feb 15, 2017 at 06:19:31PM -0800, Steve Longerbeam wrote: >> From: Russell King >> >> Setting and getting frame rates is part of the negotiation mechanism >> between subdevs. The lack of support means that a frame rate at the >> sensor can't be negotiated through the subdev path. > > Just wondering --- what do you need this for? Hi Sakari, i.MX does need the ability to negotiate the frame rates in the pipelines. The CSI has the ability to skip frames at the output, which is something Philipp added to the CSI subdev. That affects frame interval at the CSI output. But as Russell pointed out, the lack of [gs]_frame_interval op causes media-ctl to fail: media-ctl -v -d /dev/media1 --set-v4l2 '"imx6-mipi-csi2":1[fmt:SGBRG8/512x512@1/30]' Opening media device /dev/media1 Enumerating entities Found 29 entities Enumerating pads and links Setting up format SGBRG8 512x512 on pad imx6-mipi-csi2/1 Format set: SGBRG8 512x512 Setting up frame interval 1/30 on entity imx6-mipi-csi2 Unable to set frame interval: Inappropriate ioctl for device (-25)Unable to setup formats: Inappropriate ioctl for device (25) So i.MX needs to implement this op in every subdev in the pipeline, otherwise it's not possible to configure the pipeline with media-ctl. Steve