vga display output resolution wrong

Hi,

That is because you are setting wrong polarity for sync signals. For XGA polarity is negative. Make sure you are setting correct polarity using "output" sysfs entry. Some monitors are smart enough to ignore this.

Hi HardikShah,

Thanks for your reply, I check my display3 "output" sysfs entry is "component,rgb888", could you tell me what field mean polarity is? and what value should I change to?

Thanks,

Jacson

Hi Jacson,

I have pasted example below from the userguide

Set the right VENC output

echo single/double/doublediscrete/triple/triplediscrete,rgb888/yuv444p/yuv422spuv,(0/1)/(0/1)/(0/1)/(0/1) > /sys/devices/platform/vpss/display0/output

the first part is the sync mode, the second part is output data format, the last part is the polarity of the DE/FID/HS/VS, 1: ACTIVE_LOW(inverted),0:ACTIVE_HIGH(non_inverted).

Thanks,

Brijesh

Hi ,

I have the same issue. I set "echo double,yuv422spuv,0/0/1/1 > /sys/devices/platform/vpss/display1/output",

but the monitor always tell me the resolution is 1360x768x60Hz..

Hi Jack,

What i gave shows how to set the output, you require to set tripplediscrete, rgb888 as the output format to get the vga output.

echo single/double/doublediscrete/triple/triplediscrete,rgb888/yuv444p/yuv422spuv,(0/1)/(0/1)/(0/1)/(0/1) > /sys/devices/platform/vpss/display0/output

Btw, which platform and which revision you are using to get the VGA output?

Thanks,

Brijesh Jadav

Hi Jadav,

Thanks for your quickly reply. I can use HDCOMP to display 1024x768x60Hz, but the resolution of the samsung monitor(16:9) is error.

I am using RDK03.00.00.00 and my board is 8168EVM.

Hi,

I could not get, are you able to display this XGA resolution correctly from HDCOMP VENC or not? Is the Samsung monitor not displaying correctly or is not detecting the mode?

As such, it is not possible to get VGA output n EVM since sync signals are not connected from VENC to VGA connector.  Could you try connecting Component output and see if it detects correct?

thanks,

Brijesh

I can display XGA resolution from HDCOMP, but the information of the monitor(16:9) show me the input resolution is "1360x768x60Hz".

And, another monitor (4:3) detects the correct resolution. I am not sure the problem is in monitor or HDCOMP.

Hi Brijesh Jadav,

Thanks for your reply. I summary describe this issue again.

My platform is dm816x evm board using rdk03.00.00.00 to development, The resolution change of hdmi output is no problem. The problem only happen at VGA port output when I change resolution to XGA(1024x768@60Hz). I see some monitor show display infomation is "1360x768", it is not correct.

I have three display totally,

1. hdmi,

2. hdcomp(vga) tied with dvo2,

3. sd(tv)

What should I change the display "output" sysfs to? Can you give me a detail? I don't know how to config to negative as you mentioned.

Thanks,

Jacson

Hi,

if you are using dm8168EVM, TV might not detect it correctly or sometimes it may not detect at all, since on EVM, sync signals are not connected to VGA connector. If you have connected it on your EVM, you could use below command to get VGA output on HDCOMP

echo triplediscrete,rgb888,0/0/1/1 > /sys/devices/platform/vpss/display3/output

thanks,

Brijesh Jadav

Hi Brijesh Jadav,

I try the command of you provided, but I see the message "VPSS_DCTRL: invalid output value triplediscrete" show in the console.

Does it mean display driver not support this output setting?

Thanks,

Jacson

Hi Jacson,

I dont exactly remember which display sysfs folder is used for HDCOMP output, could you please check by printing the 'name' entry in each folder and use the entry which is for HDCOMP.

Thanks,

Brijesh Jadav

Hi Brijesh Jadav,

I check the name entry, the display3 is used for HDCOMP. Could you try this setting on your side?

Thanks,

Jacson