Duel display configuration

[satheshkumarman]

Hello,

I need to use DGT7 (RGB666) and DGT8 (RGB888/RGB24) with following combination.

1. video=mxcfb0:dev=ldb,LDB-DGT8,bpp=32,if=RGB24 video=mxcfb1:dev=ldb,LDB-DGT8,bpp=32,if=RGB24"

2. video=mxcfb0:dev=ldb,LDB-DGT7,bpp=32,if=RGB666 video=mxcfb1:dev=ldb,LDB-DGT8,bpp=32,if=RGB24"

For the 1st configuration, I connect DGT8 on both the channel and I see the proper display as per the RGB configuration.

For the 2nd configuration, I connect DGT7 on 1st channel and DGT8 on 2nd channel. I don't see the proper display on 1st channel, it means the display color is faded out.

To test DGT7 again, i did following configuration (both the channels are configured for RGB666).

video=mxcfb0:dev=ldb,LDB-DGT7,bpp=32,if=RGB666 video=mxcfb1:dev=ldb,LDB-DGT7,bpp=32,if=RGB666"

Now I can able to see the proper display on DGT7.

Conclusion is,  

if both the channels are configured with RGB888 and i use DGT8 (RGB888) on first channel, I get proper display. 

if both the channels are configured with RGB66 and i use DGT7 (RGB666) on first channel, I get proper display.

But If the 1st channel configured for RGB666 and 2nd channel configured for RGB24, then I'm not able to get proper display with DGT7 on 1st channel.

Now the question is, why DGT7 doesn't get proper display with step 2 configuration?

Please advice.

Thanks.

Best Regards

Sathesh Kumar Manickaraj

[BiyongSUN]

Which BSP you are using?

Have you change the display timing in devicetree in 3.10 and later.

Or the display timing in the ldb.c in 3.0.35 .

[satheshkumarman · Accepted solution]

hello biyong, thanks for the feedback. This problem is fixed now. The problem is with seralizer's data width configuration for DGT7. Initially 24 bit data width is configured for both the display types. But for DGT7 it should be 18 bit data width. Timing parameter for both display was correct already. The issue was with data width. Thanks.