Imx6 LVDS Display Problems

georg1 — Tue, 09 Apr 2019 12:45:21 GMT

Hello,

We are working with a modified version of the imx6q-apalis-eval.dtb. Our System is running fine but we recently needed to switch to a new Touch Display: https://www.telerex-europe.com/content/files/pdfs/productPdfs/POW/PH102600T009-IBC03.pdf

We have some Issues with the Displays Colors... there are strange stripes in our Colors and sometimes there are appearing purple pixels on screen.

I Modified the Device Tree Files like this:

&ldb {
    status = "okay";

    lvds-channel@0 {
        reg = <0>;
        fsl,data-mapping = "spwg";
        fsl,data-width = <24>;
        crtc = "ipu1-di0";
        primary;
        status = "okay";

        display-timings {
            native-mode = <&timing_wsvga>;
            timing_wsvga: 1024x600 {
                clock-frequency = <48000000>;
                hactive = <1024>;
                vactive = <600>;
                hback-porch = <104>;
                hfront-porch = <43>;
                vback-porch = <24>;
                vfront-porch = <20>;
                hsync-len = <5>;
                vsync-len = <5>;
                de-active = <1>;
                hsync-active = <0>;
                vsync-active = <0>;
                pixelclk-active = <0>;
            };
            /* Standard XGA timing */
            timing_xga: 1024x768 {
                clock-frequency = <65000000>;
                hactive = <1024>;
                vactive = <768>;
                hback-porch = <160>;
                hfront-porch = <24>;
                vback-porch = <29>;
                vfront-porch = <3>;
                hsync-len = <136>;
                vsync-len = <6>;
                de-active = <1>;
                hsync-active = <0>;
                vsync-active = <0>;
                pixelclk-active = <0>;
            };
        };
    };

    mxcfb1: fb@0 {
        compatible = "fsl,mxc_sdc_fb";
        disp_dev = "ldb";
        interface_pix_fmt = "RGB666";
        mode_str ="LDB-XGA";
        default_bpp = <16>;
        int_clk = <0>;
        late_init = <0>;
        status = "okay";
    };

vidargs are:

vidargs=video=mxcfb0:dev=ldb,if=RGB24,bpp=32 ldb=sin0 video=mxcfb1:off video=mxcfb2:off video=mxcfb3:off fbmem=32M

I managed to catch the issue on my phone... i cant think of a better way to send you a image of the issue... but u can clearly see the stripes, the purple pixels and the red pixels. ... this is just a picture of the floor, a red door in the background and a part of my leg... the image is displayed on our software.

I think these are the relevant parts... I tried to modify the interface_pix_fmt values and set it to something else.. but no success... maybe my display timings are off?... I cant find any relevant display timing data in that data sheet. Can somebody help me maybe?

greetings,

Georg

Re: Imx6 LVDS Display Problems

igorpadykov — Tue, 09 Apr 2019 23:31:23 GMT

Hi George

apalis board was developed and supported by toradex, it may be posted on its forum:

Welcome to - Toradex Community

Among other things may be useful to check bootargs: "if=RGB24" in one place and RGB666 in dts file.

Best regards
igor
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