Messages in this thread | | | Subject | Re: [PATCH v4 29/36] media: imx: mipi-csi2: enable setting and getting of frame rates | From | Steve Longerbeam <> | Date | Mon, 20 Feb 2017 15:47:39 -0800 |
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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 <rmk+kernel@armlinux.org.uk> >>> >>> 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
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