i.Mx6Q dual display with HDMI and LCD on linux QT

[nickruan]

Hi supporter,

My iMx6Q board is runing linux+QT, HDMI and LCD device are connected.

I want to support dual display, and set environment in uboot as follow:

setenv bootargs_mmc 'setenv bootargs ${bootargs} root=/dev/mmcblk0p1 rootwait rw video=mxcfb0:dev=lcd,TIANMA050-WVGA@60,bpp=32,if=RGB24 video=mxcfb1:dev=hdmi,1920x1080M@60,if=RGB24,bpp=32 video=mxcfb2:off ldo_active=on'

LCD can display, but HDMI can't output.

If I change the environment:

setenv bootargs_mmc 'setenv bootargs ${bootargs} root=/dev/mmcblk0p1 rootwait rw video=mxcfb1:dev=lcd,TIANMA050-WVGA@60,bpp=32,if=RGB24 video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24,bpp=32 video=mxcfb2:off ldo_active=on'

HDMI can output, but LCD can't display.

Dose it mean that kernel don't support dual display or dual dispaly is implmented by applicantion?

BRs,

[igorpadykov]

Hi nick

please try procedures described in sect.4.7 Running Linux OS on the target

attached Linux Guide.

Best regards
igor
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[nickruan]

Hi igorpadykov,

I found that LCD and HDMI can display the same content as long as HDMI resolution width is less than 1024.

I have also found the corresponding code in kernel/driver/mxc/ipu3/ipu_disp.c as follow:

void _ipu_dmfc_set_wait4eot(struct ipu_soc *ipu, int dma_chan, int width)
{
    ...

    if (width >= HIGH_RESOLUTION_WIDTH) {
        if (dma_chan == 23)
            _ipu_dmfc_init(ipu, DMFC_HIGH_RESOLUTION_DP, 0);
        else if (dma_chan == 28)
            _ipu_dmfc_init(ipu, DMFC_HIGH_RESOLUTION_DC, 0);
    }

   ...

}

HIGH_RESOLUTION_WIDTH equal to 1024 here,

Why do external handler for the width?

BRs,

Nick

[jakiewen]

你好，你的这个问题解决了吗？lvds和hdmi双屏显示同一个内容

[igorpadykov]

Hi Nick

please check Table 10. Common kernel boot parameters attached

Release Notes p.21

Best regards
igor

[jakiewen]

hi i met the same problem,how can i resolve it?  https://community.nxp.com/thread/480015