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Issue regarding about frame buffer device


Hello folks,

I am running Zybo Z7-20 Pcam petalinux project on Zybo Z7-20 board.

 I have issue regarding about frame buffer device. /dev directory is  not showing any /dev/fb0 device

boot log for xilinx drm driver as follows

[    1.509100] [drm] No max horizontal width in DT, using default 1920
[    1.515317] [drm] No max vertical height in DT, using default 1080
[    1.521578] OF: graph: no port node found in /amba_pl/xilinx_drm
[    1.527561] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[    1.534160] [drm] No driver support for vblank timestamp query.
[    1.540396] [drm] Cannot find any crtc or sizes
[    1.545341] [drm] Initialized xilinx_drm 1.0.0 20130509 for amba_pl:xilinx_drm on minor 0


Snippet from device tree as follows

&amba_pl {
    encoder_0: digilent_encoder {
        compatible = "digilent,drm-encoder";
        digilent,fmax = <150000>;
        digilent,edid-i2c = <&i2c0>;

    xilinx_drm {
        compatible = "xlnx,drm";
        xlnx,vtc = <&v_tc_out>;
        xlnx,connector-type = "HDMIA";
        xlnx,encoder-slave = <&encoder_0>;
        clocks = <&axi_dynclk_0>;
        planes {
            xlnx,pixel-format = "rgb888";
            plane0 {
                dmas = <&axi_vdma_1 0>;
                dma-names = "dma0";
when I am running modetest -M xilinx_drm command then connector status shows disconnected as given below .I have changed Desktop and cables two time but still not succeed. If i checked on baremetal application(HDMI Out) it works perfectly.

[email protected]:~# modetest -M xilinx_drm
id    crtc    type    possible crtcs    possible clones    
29    0    TMDS    0x00000001    0xffffffff

id    encoder    status        name        size (mm)    modes    encoders
30    0    disconnected    HDMI-A-1           0x0        0    29
    1 EDID:
        flags: immutable blob

    2 DPMS:
        flags: enum
        enums: On=0 Standby=1 Suspend=2 Off=3
        value: 0
    5 link-status:
        flags: enum
        enums: Good=0 Bad=1
        value: 0

id    fb    pos    size
28    0    (0,0)    (0x0)
   0 0 0 0 0 0 0 0 0 flags: ; type:

id    crtc    fb    CRTC x,y    x,y    gamma size    possible crtcs
27    0    0    0,0        0,0    0           0x00000001
  formats: RG24
    6 type:
        flags: immutable enum
        enums: Overlay=0 Primary=1 Cursor=2
        value: 1

Frame buffers:
id    size    pitch

Thanks in advance

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