Change HDMI LCD resolution in Toradex i.MX6 board

titusece · January 26, 2018, 5:31pm

Hello Experts,

I have the below 15" HDMI LCD display @1366x768 resolution and want to interface with my toradex i.MX6 board.

https://www.chalk-elec.com/?page_id=1280#!/15-6-HDMI-interface-LCD-with-capacitive-touchscreen/p/38127425

I have tried to change the resolution in uboot environment variables, but it got set some different default values.
And I tried to change the display resolution using GUI application. I can’t see my LCD resolution.

Preferences -> Monitor settings

root@apalis-imx6:~# cat /proc/cmdline 
enable_wait_mode=off vmalloc=400M ip=off root=/dev/mmcblk0p2 ro rootfstype=ext4 rootwait fec_mac=0
0:01:02:03:04:05 consoleblank=0 no_console_suspend=1 console=tty1 console=ttymxc0,115200n8 video=m
xcfb0:dev=hdmi,1366x768M@60,if=RGB16 video=mxcfb1:off video=mxcfb2:off video=mxcfb3:off fbmem=32M
root@apalis-imx6:~# 
root@apalis-imx6:~# 
root@apalis-imx6:~# fbset

mode "1280x720-60"
    # D: 74.250 MHz, H: 45.000 kHz, V: 60.000 Hz
    geometry 1280 720 1280 768 16
    timings 13468 220 110 20 5 40 5
    hsync high
    vsync high
    rgba 5/11,6/5,5/0,0/0
endmode

root@apalis-imx6:~# 
root@apalis-imx6:~#

With this 1280x720, I can’t some bottom portion of image, unable to access complete LCD. (Attached in google drive)

https://drive.google.com/open?id=1b49YnBiYxRtMjFgsrD0YyjLwG64DmECj

Also I tried the below commands to change the resolution in runtime, images are corrupted.

fbset -g 1360 768 1360 768 16 -t 14301 200 56 19 1 144 3
fbset -g 1366 768 1366 768 16 -t 14301 200 56 19 1 144 3

root@apalis-imx6:~# 
root@apalis-imx6:~# fbset -g 1360 768 1360 768 16 -t 14301 200 56 19 1 144 3
[ 1854.240082] mxc_sdc_fb fb@0: 1360x768 h_sync,r,l: 144,56,200  v_sync,l,u: 3,1,19 pixclock=69925
000 Hz
[ 1854.240100] imx-ipuv3 2400000.ipu: WARNING: adapt panel end blank lines
root@apalis-imx6:~# 
root@apalis-imx6:~# 
root@apalis-imx6:~# 
root@apalis-imx6:~# fbset -g 1366 768 1366 768 16 -t 14301 200 56 19 1 144 3
[ 1945.405040] mxc_sdc_fb fb@0: 1366x768 h_sync,r,l: 144,56,200  v_sync,l,u: 3,1,19 pixclock=69925
000 Hz
[ 1945.405057] imx-ipuv3 2400000.ipu: WARNING: adapt panel end blank lines
root@apalis-imx6:~# 
root@apalis-imx6:~#

Can you please me to solve the issue ?

Thanks for your support.

max.tx · January 27, 2018, 12:14pm

Hi

Can you provide the output to the following:

uname -r
cat /proc/cmdline 
xrandr
dmesg | grep fb
find /sys/ -name edid -exec cat {} \;

Max

titusece · January 27, 2018, 3:34pm

Hi,

Thanks for the reply.

[    0.229956] fbcvt: 1360x768@60: CVT Name - Not a CVT standard - 1.044 Mega Pixel Image


root@apalis-imx6:/# 
root@apalis-imx6:/# 
root@apalis-imx6:/# uname -r
4.1.41-2.7.3+g82f0f4f
root@apalis-imx6:/# 
root@apalis-imx6:/# 
root@apalis-imx6:/# cat /proc/cmdline 
enable_wait_mode=off vmalloc=400M ip=off root=/dev/mmcblk0p2 ro rootfstype=ext4 rootwait fec_mac=0
0:01:02:03:04:05 consoleblank=0 no_console_suspend=1 console=tty1 console=ttymxc0,115200n8 mxc_hdm
i.only_cea=1 video=mxcfb0:dev=hdmi,1366x768M@60,if=RGB16 video=mxcfb1:off video=mxcfb2:off video=m
xcfb3:off fbmem=32M
root@apalis-imx6:/# 
root@apalis-imx6:/# 
root@apalis-imx6:/# xrandr 
Screen 0: minimum 240 x 240, current 1280 x 720, maximum 8192 x 8192
DISP3 BG connected 1280x720+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
   U:1280x720p-60  60.00*+
   U:1920x1080p-50  50.00  
   U:1920x1080p-60  60.00  
   U:1920x1080p-30  30.00  
   U:1920x1080p-25  25.00  
   U:1920x1080p-24  24.00  
   U:1280x720p-120 120.00  
   U:1280x720p-100 100.00  
   U:1280x720p-50  50.00  
   U:1440x576p-50  50.00  
   U:1440x480p-60  60.00  
   U:1440x288p-50  50.08  
   U:720x576p-50  50.00  
   U:720x480p-60  59.94  
   U:1440x240p-60  59.94  
   U:640x480p-60  59.94  
root@apalis-imx6:/# 
root@apalis-imx6:/# 
root@apalis-imx6:/# dmesg | grep fb
[    0.000000] Kernel command line: enable_wait_mode=off vmalloc=400M ip=off root=/dev/mmcblk0p2 r
o rootfstype=ext4 rootwait fec_mac=00:01:02:03:04:05 consoleblank=0 no_console_suspend=1 console=t
ty1 console=ttymxc0,115200n8 mxc_hdmi.only_cea=1 video=mxcfb0:dev=hdmi,1366x768M@60,if=RGB16 video
=mxcfb1:off video=mxcfb2:off video=mxcfb3:off fbmem=32M
[    0.229926] fbcvt: Aspect ratio not CVT standard
[    0.229956] fbcvt: 1360x768@60: CVT Name - Not a CVT standard - 1.044 Mega Pixel Image
[    0.230132] mxc_sdc_fb fb@0: registered mxc display driver hdmi
[    0.238402] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[    0.286740] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[    0.348757] mxc_sdc_fb fb@1: mxcfb1 is turned off!
[    0.348921] mxc_sdc_fb fb@2: mxcfb2 is turned off!
[    0.349077] mxc_sdc_fb fb@3: mxcfb3 is turned off!
[    7.653229] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[    7.712743] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[    7.766675] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[    7.817058] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[    8.260242] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[ 1899.540112] mxc_sdc_fb fb@0: 640x480 h_sync,r,l: 96,16,48  v_sync,l,u: 2,10,33 pixclock=2517500
0 Hz
[ 1899.641527] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[ 1899.692427] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[ 1899.791876] mxc_sdc_fb fb@0: 640x480 h_sync,r,l: 96,16,48  v_sync,l,u: 2,10,33 pixclock=2517500
0 Hz
[ 1899.857975] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
root@apalis-imx6:/# 
root@apalis-imx6:/# 
root@apalis-imx6:/# 
root@apalis-imx6:/# 
root@apalis-imx6:/# 
root@apalis-imx6:/# 
root@apalis-imx6:/# find /sys/ -name edid -exec cat {} \;
0xFF 0xFF 0x01 0xFF 0xFF 0xFF 0xFF 0xFF 0x06 0xAF 0x3C 0x10 0x00 0x00 0x00 0x00 
0x00 0x16 0x01 0x04 0x90 0x1F 0x11 0x78 0x02 0x10 0xB5 0x97 0x58 0x57 0x92 0x26 
0x00 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0x01 0x01 0x01 0x01 0x01 0x01 0x01 0x01 
0x01 0x01 0x01 0x01 0x01 0x01 0xCE 0x1D 0x56 0xD2 0x50 0x00 0x26 0x30 0x10 0x10 
0x3E 0x00 0x35 0xAD 0x10 0x00 0x00 0x18 0xDF 0x13 0x56 0xD2 0x50 0x00 0x26 0x30 
0x10 0x10 0x3E 0x00 0x35 0xAD 0x10 0x00 0x00 0x18 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x02 
0x00 0x0C 0x39 0xCC 0x0D 0x3C 0x64 0x0F 0x0C 0x1B 0x6F 0x20 0x20 0x20 0x00 0x0D 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 
root@apalis-imx6:/# 
root@apalis-imx6:/#

max.tx · January 29, 2018, 5:53pm

Hi

Could you change your vidargs to the following:

video=mxcfb0:dev=hdmi,1366x768M@60,if=RGB24 video=mxcfb1:off video=mxcfb2:off video=m xcfb3:off fbmem=32M

Note that if you cat and paste the edid which is read from your display at least the following online tool reports a wrong checksum. I don’t know if the driver in the kernel ignores such an error or not.

Max

titusece · February 7, 2018, 3:02pm

I have tried the below

 video=mxcfb0:dev=hdmi,1366x768M@60,if=RGB32 video=mxcfb1:off video=mxcfb2:off video=m xcfb3:off fbmem=32M

 video=mxcfb0:dev=hdmi,1360x768M@60,if=RGB32 video=mxcfb1:off video=mxcfb2:off video=m xcfb3:off fbmem=32M

And got scrambled images, BTW, this LCD works with Desktop PC. (windows & LCD @ 1366x768)
Can you please help me on this ?

root@apalis-imx6:/# dmesg | grep fb
[    0.000000] Kernel command line: enable_wait_mode=off vmalloc=400M ip=off root=/dev/mmcblk0p2 r
o rootfstype=ext4 rootwait fec_mac=00:01:02:03:04:05 consoleblank=0 no_console_suspend=1 console=t
ty1 console=ttymxc0,115200n8 video=mxcfb0:dev=hdmi,1366x768M@60,if=RGB32 video=mxcfb1:off video=mx
cfb2:off video=mxcfb3:off fbmem=32M
[    0.229964] fbcvt: Aspect ratio not CVT standard
[    0.229992] fbcvt: 1360x768@60: CVT Name - Not a CVT standard - 1.044 Mega Pixel Image
[    0.230164] mxc_sdc_fb fb@0: registered mxc display driver hdmi
[    0.238273] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[    0.286712] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[    0.348758] mxc_sdc_fb fb@1: mxcfb1 is turned off!
[    0.348920] mxc_sdc_fb fb@2: mxcfb2 is turned off!
[    0.349075] mxc_sdc_fb fb@3: mxcfb3 is turned off!
[    1.303359] mxc_sdc_fb fb@0: 640x480 h_sync,r,l: 96,16,48  v_sync,l,u: 2,10,33 pixclock=2517500
0 Hz
[    2.608952] mxc_sdc_fb fb@0: 640x480 h_sync,r,l: 96,16,48  v_sync,l,u: 2,10,33 pixclock=2517400
0 Hz
[    2.656093] mxc_sdc_fb fb@0: 640x480 h_sync,r,l: 96,16,48  v_sync,l,u: 2,10,33 pixclock=2517400
0 Hz
[    2.772971] mxc_sdc_fb fb@0: 640x480 h_sync,r,l: 96,16,48  v_sync,l,u: 2,10,33 pixclock=2517500
0 Hz
[    2.876204] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[    7.176103] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[    7.249564] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[    7.313333] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[    7.400405] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[    7.852579] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
root@apalis-imx6:/# 




root@apalis-imx6:/# dmesg | grep fb
[    0.000000] Kernel command line: enable_wait_mode=off vmalloc=400M ip=off root=/dev/mmcblk0p2 r
o rootfstype=ext4 rootwait fec_mac=00:01:02:03:04:05 consoleblank=0 no_console_suspend=1 console=t
ty1 console=ttymxc0,115200n8 video=mxcfb0:dev=hdmi,1360x768M@60,if=RGB32 video=mxcfb1:off video=mx
cfb2:off video=mxcfb3:off fbmem=8M
[    0.230039] fbcvt: Aspect ratio not CVT standard
[    0.230068] fbcvt: 1360x768@60: CVT Name - Not a CVT standard - 1.044 Mega Pixel Image
[    0.230238] mxc_sdc_fb fb@0: registered mxc display driver hdmi
[    0.238427] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[    0.286728] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[    0.348768] mxc_sdc_fb fb@1: mxcfb1 is turned off!
[    0.348933] mxc_sdc_fb fb@2: mxcfb2 is turned off!
[    0.349091] mxc_sdc_fb fb@3: mxcfb3 is turned off!
[    1.303376] mxc_sdc_fb fb@0: 640x480 h_sync,r,l: 96,16,48  v_sync,l,u: 2,10,33 pixclock=2517500
0 Hz
[    2.542163] mxc_sdc_fb fb@0: 640x480 h_sync,r,l: 96,16,48  v_sync,l,u: 2,10,33 pixclock=2517400
0 Hz
[    2.586135] mxc_sdc_fb fb@0: 640x480 h_sync,r,l: 96,16,48  v_sync,l,u: 2,10,33 pixclock=2517400
0 Hz
[    2.719720] mxc_sdc_fb fb@0: 640x480 h_sync,r,l: 96,16,48  v_sync,l,u: 2,10,33 pixclock=2517500
0 Hz
[    2.849922] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[    7.279785] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[    7.349631] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[    7.413350] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[    7.500416] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
[    7.953522] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250
000 Hz
root@apalis-imx6:/# 
root@apalis-imx6:/#

jaski.tx · February 9, 2018, 7:52am

are you able to see full screen now, can you post a picture of your display.

titusece · February 9, 2018, 3:13pm

Hi jaski.tx,
Getting 1280x720 resolution as we can see the below log for both 1360x768 & 1366x768.

[ 0.230039] fbcvt: Aspect ratio not CVT standard
[ 0.230068] fbcvt: 1360x768@60: CVT Name - Not a CVT standard - 1.044 Mega Pixel Image
[ 7.349631] mxc_sdc_fb fb@0: 1280x720 h_sync,r,l: 40,110,220 v_sync,l,u: 5,5,20 pixclock=74250

Also please check the kernel command line which I set in uboot.

[ 0.000000] Kernel command line: enable_wait_mode=off vmalloc=400M ip=off root=/dev/mmcblk0p2 ro rootfstype=ext4 rootwait fec_mac=00:01:02:03:04:05 consoleblank=0 no_console_suspend=1 console=tty1 console=ttymxc0,115200n8 video=mxcfb0:dev=hdmi,1360x768M@60,if=RGB32 video=mxcfb1:off video=mx
cfb2:off video=mxcfb3:off fbmem=8M

[ 0.000000] Kernel command line: enable_wait_mode=off vmalloc=400M ip=off root=/dev/mmcblk0p2 ro rootfstype=ext4 rootwait fec_mac=00:01:02:03:04:05 consoleblank=0 no_console_suspend=1 console=tty1 console=ttymxc0,115200n8 video=mxcfb0:dev=hdmi,1366x768M@60,if=RGB32 video=mxcfb1:off video=mxcfb2:off video=mxcfb3:off fbmem=32M

Not sure why 1280x768 resolution is set even I use 1366x768. Got the below image.
https://drive.google.com/file/d/1b49YnBiYxRtMjFgsrD0YyjLwG64DmECj/view
Anything I need to modify in dts or HDMI driver ?

Also tried the below commands, but got some scrambled images.

fbset -g 1366 768 1366 768 18 -t 13468 220 110 20 5 40 5

fbset -g 1366 768 1366 768 32 -t 13468 220 110 20 5 40 5

Thanks for the reply.

titusece · February 9, 2018, 3:42pm

Just saw the below post.

I can’t see the 1366x768 or 1360x768 resolution. (In imx6, 1366 is not divisible by 8, so I think we should use 1360)

root@apalis-imx6:/# cat /sys/class/graphics/fb0/modes
U:1280x720p-60
U:640x480p-59
U:1280x720p-120
U:1280x720p-100
U:1920x1080p-30
U:1920x1080p-25
U:1920x1080p-24
U:1920x1080p-50
U:1440x576p-50
U:1440x576p-50
U:1440x288p-50
U:1440x288p-50
U:1280x720p-50
U:720x576p-50
U:720x576p-50
U:1920x1080p-60
U:1440x480p-60
U:1440x480p-60
U:1440x240p-60
U:1440x240p-60
U:1280x720p-60
U:720x480p-60
U:720x480p-60
U:640x480p-60
root@apalis-imx6:/# 
root@apalis-imx6:/#

Can you please help me on this ?
Thanks.

titusece · February 10, 2018, 3:18pm

Hi,
Attached the video. You can see the some lines shifted from top to bottom.

Can you please check ?

max.tx · February 11, 2018, 11:43am

Hi

As already said your display provides broken EDID. Both EDID header and checksum are wrong. I’m surprised that a Windows PC does parse such data.

You should contact your display provider and report the issue.

To workaround the broken display you could make the kernel use local EDID instead of reading it from the display.

For that apply this patch and add CONFIG_I2C_SW_EDID to the kernel config.
Then change the device tree to contain a corrected EDID and make the edid driver use the simulated I2C bus driver instead of reading from the I2C bus towards your display, e.g. similar what the following patch does to the Evaluation Board device trees.

Then compile the kernel and device tree and deploy to the target.

Max

Note that the restriction that the resolution must be a multiple of 8 is limited to an are were the GPU renders to, the IPU can generate display output without that restriction. When you use a window manager (e.g. openbox in the LXDE image) then the GPU will be asked to draw to a part of the full display. The dimensions of such a sub window will be a multiple of 8.

titusece · February 12, 2018, 5:50pm

Thanks Max… Its fixed the issue. Now I can get the full resolution on my HDMI display.
Thanks for the help.

Harish · February 14, 2018, 7:54pm

Hi @max.tx, @Titus_Stalin,

We are using the same below 15.6 display with Toradex imx6Q Apalis SOM but we have ported Android 7.1.2 to it
https://www.chalk-elec.com/?page_id=1280#!/15-6-HDMI-interface-LCD-with-capacitive-touchscreen/p/38127425

We have enabled local EDID patch - new driver and dts file changes
We have configured 1366x768 as resolution in the hdmi driver // Tried with 1360x768 as well, which is the better tool to get the display parameters to be filled for this resolution in the driver
We made sure the bootargs are fine - video=mxcfb0:dev=hdmi,1366x768M@60,if=RGB24 //did try with rgb16 as well as rgb32

Are we missing anything here - which stops us in quickly validating this 15.6 display with Toradex imx6Q

Hi @Titus_Stalin,

Have you created the local EDID for this display on your own with 1366x768 as resolution - where did you make out other parameters for this display

If possible could you pls upload a complete working patch to this display so that we can cross verify

Please help us get over this issue

Thanks

Harish

marcel.tx · February 14, 2018, 9:49pm

Please note that hijacking old questions is discouraged. Please do ask a new question referring to this one if deemed required.

Harish · February 15, 2018, 3:13am

Sure marcel.tx, will raise a new one

titusece · February 23, 2018, 2:46pm

That corrupted EDID HDMI display workd with raspberry pi device with the following fix.
https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=205958&p=1277210#p1277210

max.tx · February 28, 2018, 10:04pm

That Raspberrypy fix seems to use kernel extensions only available in the raspberrypy downstream kernel. What exactly is not working for you in the following workaround? Change HDMI LCD resolution in Toradex i.MX6 board - #10 by max.tx - Technical Support - Toradex Community