From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steve Longerbeam Subject: Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and getting of frame rates Date: Mon, 20 Feb 2017 15:47:39 -0800 Message-ID: <028a05fb-f5e8-d4ed-b0bd-39b93b56dfac@gmail.com> 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=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <6892fb15-2d18-4898-c328-3acff9d6cc39-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Sakari Ailus Cc: robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, shawnguo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, kernel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org, fabio.estevam-3arQi8VN3Tc@public.gmane.org, linux-I+IVW8TIWO2tmTQ+vhA3Yw@public.gmane.org, mchehab-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, hverkuil-qWit8jRvyhVmR6Xm/wNWPw@public.gmane.org, nick-gcszYUEDH4VrovVCs/uTlw@public.gmane.org, markus.heiser-O6JHGLzbNUwb1SvskN2V4Q@public.gmane.org, p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org, laurent.pinchart+renesas-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org, bparrot-l0cyMroinI0@public.gmane.org, geert-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org, arnd-r2nGTMty4D4@public.gmane.org, sudipm.mukherjee-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, minghsiu.tsai-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org, tiffany.lin-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org, jean-christophe.trotin-qxv4g6HH51o@public.gmane.org, horms+renesas-/R6kz+dDXgpPR4JQBCEnsQ@public.gmane.org, niklas.soderlund+renesas-1zkq55x86MTxsAP9Fp7wbw@public.gmane.org, robert.jarzmik-GANU6spQydw@public.gmane.org, songjun.wu-UWL1GkI3JZL3oGB3hsPCZA@public.gmane.org, andrew-ct.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org, gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, shuah-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, sakari.ailus-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, pavel-+ZI9xUNit7I@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-me List-Id: devicetree@vger.kernel.org On 02/20/2017 02:56 PM, 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. > Hi Russell, But Sakari brings up a good point. The mipi csi-2 receiver doesn't have any control over frame rate, so why do you even need to give it this information via media-ctl? Steve -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html