i.MX8 MIPI rate question

[xu_ji1]

Hello,

We used i.MX8QP and Ti DS960 deserializer as transform camera data.

When set ds960 CSI TX data rate to 1.2Gbps,connect four 1080P cameras capture image at same time,

all images are no problem;when set ds960 CSI TX data rate to 1.6Gbps,

connect four 1080P cameras capture image at same time,

all images data not good,some pixel data missing.

What makes this problem?does i.MX8 not support high MIPI data rate?

[xu_ji1]

hello,

How about the conclution？ Do i.MX8QP and i.MX8QXP support 4X1080P@30fps cameras at 1.6Gbps TX?

[joanxie]

I only can say for imx8qm or imx8qxp side, which can support 4x1080p@30 with 16bpp, if you need to support this, you need enable 4-lane, For 1080P30 camera, its pixel clock is about 74.25Mhz, so for each if use 16bpp data rate = 74.25M * 16bpp = 1188Mbps. So 4xcamera bandwidth is 4.752Gbps.

[xu_ji1]

Where is enabled the 4-lanes on i.MX8QP？pls give detail guide

[joanxie]

data-lanes = <1 2 3 4>; this is for data lane settings,since you set the four 1080p camera successfully when you set the DS960 to 1.2G, but failed when you set DS960 to 1.6G, which means that imx8qm can support 4 1080p camera, you should check the DS960 settings

[joanxie]

what's camera settings different from DS960  1.2G to 1.6G? you can calculate by yourself, the imx8qp supports up to 6Gbps, if your 4 camera is 1080p 16bpp, should be 148.5Mx16bppx4>6Gbps

[xu_ji1]

camera setting not diff with 1.2G and 1.6G,only ds960 CSI TX rate register setting diff.

why 1.2G setting is ok for i.mx8qp?

How about 148.5M? how to calculate it?

[joanxie]

for imx8qp, The MIPI CSI-2 IP provides MIPI CSI-2 standard camera interface ports. The MIPI
CSI-2 interface supports up to 1.5 Gbps for up to 4 data lanes

when you use the 1.6Gbps, did you set the imx8qp mipi csi as 4 lanes?

[joanxie]

do you use DS90UB960? as I known DS90UB960 supportts 4lane, maybe you need to check the DS90UB960 side, I think maybe your DS90UB960 set as 1.6Gx4lane?? since 1.2G can support 4 1080p camera, why do you need to change to 1.6G? we don't test DS90UB960 ever, but tested MAX9286 with 4 camera successfully

[xu_ji1]

yes it is DS90UB960,I just want to check the max mipi rate of platform,

previous said the imx8qp supports up to 6Gbps,and 1.6G with 4X1080P cameras >6Gbps,

is it keypoint?

MAX9286 support 4X1280X800 cameras as I know.

and also I try it on i.MX8QXP ds960 set 1.2G can not support 4X1080P cameras,only support 3X1080P+

1X720P cameras,what is 8QXP supports up?

[joanxie]

what frame rate do you use for all of your user case??

[xu_ji1]

30fps

[xu_ji1]

Hello,

Where set mipi csi as 4lanes, in my dtsi has code:

&mipi_csi_0 {
#address-cells = <1>;
#size-cells = <0>;
virtual-channel;
status = "okay";

/* Camera 0 MIPI CSI-2 (CSIS0) */
port@0 {
reg = <0>;
mipi_csi0_ep: endpoint {
remote-endpoint = <&ds960_0_ep>;
data-lanes = <1 2 3 4>;
};
};
};

is it ok?