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How to use osd0 in 1920 x 1080 mode on DM6446

Hi all,

I have a custom board with DM6443 and MV kernel 2.6.18 coming with DVSDK 2.0.0.22.

I want to use osd0 fb in 1920 x 1080 mode.

Currently, the max. resolution I can use is 1280 x 960.

I am using the following kernel command line to initialize the OSD fb:

video=davincifb:osd0=1280x960x16,5500K ...

Kernel boot messages:

davincifb davincifb: dm_osd0_fb: Initial window configuration is invalid.
davincifb davincifb: dm_osd0_fb: 1280x960x16@0,0 with framebuffer size 5500KB

...

=> When Linux is booted I can select the mode by fbset and can use it ....

 

For 1920 x 1080 I need more fb memory for OSD0

1920 x 1080 x 2 x 2 = 8100K

But even when I try to extend the memory to 5600K I get the following:

Kernel command line:

video=davincifb:osd0=1280x960x16,5600K ...

Kernel boot messages:

davincifb davincifb: dm_osd0_fb: Initial window configuration is invalid.
davincifb davincifb: dm_osd0_fb: 1280x960x16@0,0 with framebuffer size 5600KB

...

davincifb davincifb.0: dm_osd0_fb: dma_alloc_coherent failed when allocating framebuffer.
davincifb: probe of davincifb.0 failed with error -12

=> there seems to be a limitation to ~ 5500K of memory for OSD0

 

When I try to extend the resolution to 1920x1080 I get the following:

Kernel command line:

video=davincifb:osd0=1920x1080x16,5500K ....

Kernel boot messages:

davincifb davincifb: dm_osd0_fb: Initial window configuration is invalid.
davincifb davincifb: dm_osd0_fb: 1920x1080x16@0,0 with framebuffer size 5500KB
...

When Linux has booted, I'm not able to select more than 960 lines with fbset.

 

So, I see 2 limitations at the moment:

- Memory for OSD0 can not be larger than 5500K

- osd0 framebuffer can not have more than 960 lines

 

Am I missing something?

Where are these limitations coming from?

Can these limits be extended for my use case?

What is the reason for the error message "Initial window configuration is invalid"? I don't get the message if I use 720x576 resolution or below for kernel command line

 

Thanks a lot in advance!

Best regards,

Thomas