[Yocto BSP 1.8] i.MX6DP Display issue on LVDS dual channel panel

[charleshuang]

u-boot setting:

setenv mmcargs setenv bootargs console=${console},${baudrate} ${smp} root=${mmcroot} ${bootargs} video=mxcfb0:dev=ldb,if=RGB24 fbmem=24M

LVDS dual channel setting in dts file:

&ldb {

  status = "okay";

};

&mxcfb1 {

  status = "okay";

};

&mxcfb2 {

  disp_dev = "ldb";

  mode_str ="1280x1024M@60";

  status = "okay";

};

&mxcfb3 {

  disp_dev = "ldb";

  mode_str ="1280x1024M@60";

  status = "okay";

};

&ldb {

  ext_ref = "true";

  status = "okay";

  split-mode;

  lvds-channel@0 {

  fsl,data-mapping = "spwg";

  fsl,data-width = <24>;

  crtc = "ipu2-di0";

  primary;

  status = "okay";

  display-timings {

                        native-mode = <&timing0>;

                        timing0: g190eg01v1 {

                                clock-frequency = <54000000>;

                                hactive = <640>;

                                vactive = <1024>;

                                hback-porch = <108>;

                                hfront-porch = <40>;

                                vback-porch = <3>;

                                vfront-porch = <29>;

                                hsync-len = <68>;

                                vsync-len = <7>;

                        };

                };

  };

  lvds-channel@1 {

                fsl,data-mapping = "spwg";

                fsl,data-width = <24>;

                crtc = "ipu1-di1";

                status = "okay";

  display-timings {

                        native-mode = <&timing1>;

                        timing1: g190eg01v1 {

                                clock-frequency = <54000000>;

                                hactive = <640>;

                                vactive = <1024>;

                                hback-porch = <108>;

                                hfront-porch = <40>;

                                vback-porch = <3>;

                                vfront-porch = <29>;

                                hsync-len = <68>;

                                vsync-len = <7>;

                        };

                };

  };

};

When the device display QT window on LVDS dual channel panel (1280*1024 resolution), the quality of the image is very poor.

Please see attached file.

Can you tell me how to modify dts file?

Thank you.

Original Attachment has been moved to: lvds_pictures.zip

[alejandrolozan1]

Hi,

Which BSP version are you using?

Are you trying to get an extended desktop or just clone the desktop?

Best Regards,

Alejandro

[charleshuang]

Hi alejandrolozano,

I use BSP version is 3.14.52.

No. I just want to display QT desktop on a dual channel of lvds panel.

Thanks.

Best Regards,

Alex

[强王]

this is my dts config:

  lvds_display: fb@0 {

        compatible = "fsl,mxc_sdc_fb";

        disp_dev = "ldb";

        interface_pix_fmt = "RGB24";

        mode_str ="LDB-XGA";

        default_bpp = <32>;

        int_clk = <0>;

        late_init = <0>;

        status = "okay";

    };

&ldb {

    status = "okay";

    split-mode;

    lvds-channel@0 {

        reg = <0>;

        crtc = "ipu2-di0";

        fsl,data-mapping = "spwg";

        fsl,data-width = <24>;

        status = "okay";

        display-timings {

            native-mode = <&timing0>;

            timing0: g104xvn01 {

                clock-frequency = <130000000>;

                hactive = <1920>;

                vactive = <720>;

                hback-porch = <40>;

                hfront-porch = <40>;

                vback-porch = <15>;

                vfront-porch = <15>;

                hsync-len = <80>;

                vsync-len = <10>;

            };

        };

    };

    lvds-channel@1 {

        reg = <1>;

        crtc = "ipu2-di1";

        fsl,data-mapping = "spwg";

        fsl,data-width = <24>;

        status = "okay";

        primary;

        display-timings {

            native-mode = <&timing1>;

            timing1: g104xvn01 {

                clock-frequency = <130000000>;

                hactive = <1920>;

                vactive = <720>;

                hback-porch = <40>;

                hfront-porch = <40>;

                vback-porch = <15>;

                vfront-porch = <15>;

                hsync-len = <80>;

                vsync-len = <10>;                                                                                                                            

            };

        };

    };

};

[charleshuang]

I try your method, it also cannot work. It works fine on i.MX6. But this issue is occurred  on i.MX6DP.

Can you tell me how to solve this issue on i.MX6DP?

Thanks.