Screen connected to HDMI stays black


(hans mayer) #1

Dear All,

I am running a banana pi M64 with aarch64 GNU/Linux with an image from 2017-08-13-debian-8-jessie-mate-desktop-preview-aarch64-bpi-m64-sd-emmc.img

I am facing some issues with the HDMI interface I didn’t see with the M3 I have too. I connect a Dell screen with a cable with HDMI interface to M64 and DVI to the Dell monitor. To see the boot process I have to switch off and on the screen, otherwise it stays dark. This doesn’t happen with a M3. But this isn’t actually my problem. In the meantime I know how to fix it.

If I connect an (older) Samsung screen it stays dark at all. The Samsung monitor works with a banana pi M3 and to my MacBook pro. It is also connected with such a cable, HDMI on one side and DVI on the other.

I assume the screen resolution can’t be handled by Samsung monitor. I found a documentation BPI-M64: how to change HDMI mode from 720P to 1080P But I don’t have such a file a64-2GB-sd.dts.1080p

On partition 1 there are some files:
/mnt/bananapi/bpi-m64/linux/1080p/sun50i-a64-bpi-m64-1080p.dtb
/mnt/bananapi/bpi-m64/linux/480p/sun50i-a64-bpi-m64-480p.dtb
/mnt/bananapi/bpi-m64/linux/720p/sun50i-a64-bpi-m64-720p.dtb
/mnt/bananapi/bpi-m64/linux/lcd5/sun50i-a64-bpi-m64-lcd5.dtb
/mnt/bananapi/bpi-m64/linux/lcd7/sun50i-a64-bpi-m64-lcd7.dtb

m64:root> ls -l /usr/lib/u-boot/bananapi/bpi-m64/
total 2020
-rw-r--r-- 1 root root 409643 Aug 10  2017 u-boot-with-dtb-bpi-m64-1080p-8k.img.gz
-rw-r--r-- 1 root root 409641 Aug 10  2017 u-boot-with-dtb-bpi-m64-480p-8k.img.gz
-rw-r--r-- 1 root root 409642 Aug 10  2017 u-boot-with-dtb-bpi-m64-720p-8k.img.gz
-rw-r--r-- 1 root root 409647 Aug 10  2017 u-boot-with-dtb-bpi-m64-lcd5-8k.img.gz
-rw-r--r-- 1 root root 409646 Aug 10  2017 u-boot-with-dtb-bpi-m64-lcd7-8k.img.gz

For me it’s not clear which image or configuration is used at boot process. On partition 1 there is no “uEnv.txt” only

m64:root> ls -la /mnt 
total 32
drwxr-xr-x  4 root root 16384 Jan  1  1970 .
drwxr-xr-x 24 root root  4096 Jul  2 13:33 ..
drwxr-xr-x  3 root root  4096 Aug 10  2017 bananapi
drwxr-xr-x  2 root root  4096 Jun 14 15:53 System Volume Information
-rwxr-xr-x  1 root root   366 Feb 14  2017 .uEnv.txt.org
m64:root> cat /mnt/.uEnv.txt.org 
console=tty0 console=ttyS0,115200n8 no_console_suspend board=bpi-m64
#fdt_filename=bananapi/bpi-m64/linux/a64-2GB.dtb
fdt_filename=bananapi/bpi-m64/linux/a64-2GB-sd.dtb
kernel_filename=bananapi/bpi-m64/linux/Image
initrd_filename=bananapi/bpi-m64/linux/initrd.img
ethaddr=36:c9:e3:f1:b8:05
optargs=disp.screen0_output_mode=720p60
root=/dev/mmcblk0p2
init=/sbin/init

Of course I can connect a serial interface with 115200 bd, which works fine. But to have a working HDMI interface would be nice.

Any further help is welcome.

Kind regards
Hans