Wandboard Kernel 4.4 HDMI Resolution

Discussion of your EDM baseboard, your add-on boards or other peripherals for your wandboard.

Wandboard Kernel 4.4 HDMI Resolution

Postby deepteriar » Thu Aug 24, 2017 4:26 am

Hi,
I am using Yocto linux kernel 4.4 on wandboard. I have connected a Waveshare 7 inch HDMI 800x480 which is having a capacitive touch. This is my bootargs:
console=ttymxc0,115200 root=/dev/mmcblk0p2 rootwait rw video=mxcfb0:dev=hdmi,800x480M@60,if=RGB24,bpp=32
Now when the board boots, the right side part of the display is going out of screen i.e I am not able to see the full screen.Even from the splash screen,the image does not come in exact middle of the screen.It is shifting to right.
I am currently using the core-image-sato.
What changes do i need to do so that images come in between. Also when I see /sys/class/graphics/fb0/modes
it is showing the following:

root@wandq:~# cat /sys/class/graphics/fb0/modes
U:1024x768p-0
Can anyone help me regarding this?
Thanks
deepteriar
 
Posts: 4
Joined: Thu Aug 24, 2017 4:23 am

Re: Wandboard Kernel 4.4 HDMI Resolution

Postby Richard » Mon Aug 28, 2017 1:28 pm

Hello deepteriar:

It looks there is HDMI output signal but the framebuffer isn't initialized properly.

For wandboard linux 4.1.15, it also requires some fixes to get HDMI work.
https://github.com/wandboard-org/linux/commit/395a353fa0f5f6b929b109d08e3fb2a812e107f2

I'm not sure if it also works for your case?

Could i ask what kernel source code you use - linux kernel 4.4 from linux-stable as below ?
( https://github.com/jumpnow/meta-wandboard/blob/jethro/recipes-kernel/linux/linux-stable_4.4.bb )

BR,

Richard
Richard
Site Admin
 
Posts: 138
Joined: Tue Dec 17, 2013 6:57 am

Re: Wandboard Kernel 4.4 HDMI Resolution

Postby deepteriar » Tue Aug 29, 2017 5:33 am

HI Richard,

Thanks for reply.

I am using the linux_stable4.4.bb to build my kernel.
If I am using a bigger HDMI screen, with 1920x1080 it is working fine i.e I am able to see the full screen.
But the customer requirement is a smaller HDMI i.e why we are using 800x480 resolution. BUt in this case not able to see the full screen.

Thanks
deepteriar
 
Posts: 4
Joined: Thu Aug 24, 2017 4:23 am


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