From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752232AbdBUMQY (ORCPT ); Tue, 21 Feb 2017 07:16:24 -0500 Received: from nblzone-211-213.nblnetworks.fi ([83.145.211.213]:53286 "EHLO hillosipuli.retiisi.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752100AbdBUMQV (ORCPT ); Tue, 21 Feb 2017 07:16:21 -0500 Date: Tue, 21 Feb 2017 14:15:42 +0200 From: Sakari Ailus To: Steve Longerbeam 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 Subject: Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and getting of frame rates Message-ID: <20170221121542.GH16975@valkosipuli.retiisi.org.uk> 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> <6892fb15-2d18-4898-c328-3acff9d6cc39@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6892fb15-2d18-4898-c328-3acff9d6cc39@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Steve, On Mon, Feb 20, 2017 at 02:56:15PM -0800, Steve Longerbeam wrote: > > > 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. The frame rate is only set on the sub-device which you explicitly set it. I.e. setting the frame rate fails if it's not supported on a pad. Philipp recently posted patches that add frame rate propagation to media-ctl. Frame rate is typically settable (and gettable) only on sensor sub-device's source pad, which means it normally would not be propagated by the kernel but with Philipp's patches, on the sink pad of the bus receiver. Receivers don't have a way to control it nor they implement the IOCTLs, so that would indeed result in an error. -- Kind regards, Sakari Ailus e-mail: sakari.ailus@iki.fi XMPP: sailus@retiisi.org.uk