iMX6 incorrect screen resolution

Technical Support
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1

Hello,

I am using an embedded Linux distribution built with Buildroot on my Apalis iMX6 target. I installed Xorg (xserver 1.20.7) with dwm 6.2 as window manager and xterm-349 as terminal.
Whenever I launch Xorg (using startx) it starts up as expected, but it only uses a small part of my monitor.

I’ve tried to change the resolution with xrandr to no avail (using this as main source, but for a resolution of 1280x800).
When I execute ‘xrandr -q’ it outputs:

Screen 0: minimum 640 x 480, current 640 x 480, maximum 640 x 480
default connected 640x480+0+0 0mm x 0mm
  640x480        0.00*

I’m mainly confused as to why it shows the same values for minimal, maximal and current resolution. The screen definitely supports different resolutions. I also don’t understand why it shows default as the device instead of HDMI-1 for example. The screen I’m using is a: Joy-it RB-LCD10-2 Touchscreen 10" 1280x800p HDMI

Does anyone have any suggestions on how to solve this problem or can you point me in the right direction?

Thank you.

2

Hi @Johan and Welcome to the Toradex Community!

Could you provide the Bsp version of your module?
Have you done any changes to the Software? If yes, can you share them?

Regarding the correct setting of display resolution, please have a look here.

Best regards,
Jaski

3

Hi Jaski,

I was using the following buildroot settings:

BR2_LINUX_KERNEL_DEFCONFIG="imx_v6_v7"
BR2_LINUX_KERNEL_INTREE_DTS_NAME="imx6q-apalis-ixora-v1.1"

I didn’t notice that there was a toradex_apalis_imx6_defconfig, however using this one seems to solve the problem. It makes use of a different kernel, which probably has additional drivers and enables me to get the correct screen resolution. The relevant buildroot settings can be summarized as follows:

BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_4_9=y
BR2_LINUX_KERNEL_CUSTOM_REPO_URL="git://git.toradex.com/linux-toradex.git"
BR2_LINUX_KERNEL_CUSTOM_REPO_VERSION="d899927728beca8357a5b4120b690cb3c1d80844"
BR2_LINUX_KERNEL_INTREE_DTS_NAME="imx6q-apalis-ixora-v1.1"

Additionally I had to pass the video arguments during the u-boot boot process i.e. change the bootargs:

setenv bootargs "${bootargs} ${vidargs}"

This seems to solve my problem. I am however still curious about what the difference is between the 2 Linux kernels I tried to use. Which specific hardware drivers are necessary?

4

Sorry, but we do not officially support Builroot. Should you use any of our officially supported BSPs you may find more information concerning the configuration of display output, resolution and timings here: