topic Re: i.Mx6Q dual display with HDMI and LCD on linux QT in i.MX Processors

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

nickruan — Sat, 04 Feb 2017 07:48:07 GMT

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,

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

igorpadykov — Mon, 06 Feb 2017 05:09:27 GMT

Hi nick

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

attached Linux Guide.

Best regards
igor
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Re: i.Mx6Q dual display with HDMI and LCD on linux QT

nickruan — Tue, 07 Feb 2017 08:26:06 GMT

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

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

igorpadykov — Tue, 07 Feb 2017 10:25:26 GMT

Hi Nick

please check Table 10. Common kernel boot parameters attached

Release Notes p.21

Best regards
igor

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

jakiewen — Tue, 17 Jul 2018 06:06:34 GMT

你好，你的这个问题解决了吗？lvds和hdmi双屏显示同一个内容

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

jakiewen — Mon, 13 Aug 2018 03:10:47 GMT

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