RZG1M Display configuration in RGB888 format settings

Hello,

 

We are using the elinux yocto 2.0 build system, we would like to configure our display in RGB888 format, where we need to modify to make it work for RGB888 format?

Note : we are using the lvds display which support the RGB888 format.

 

Regards,

Charan

  • In reply to Charan K S:

    Hi Charan,

    Ok, 'img pix fmt' of 1 means RGB565 in the graphics library, so that is confirmed.

    I would suggest these as next steps -

    1. Remove the line 'transform=180' or any other line from the [output] section in weston.ini other than the lines for 'name' and 'mode'. I think if you have any other parameter there that may be overriding the flag 'name=current'. I.e. the section should look like this -

    [output]
    name=LVDS-1
    mode=current

    2. Completely remove the usage of the graphics library -
    2.1. Make sure Weston is not using the GPU for composition. Check the file /etc/defaults/weston and verify that OPTARGS has this part in it -> "--use-v4l2".
    2.2. Rename the file /etc/init.d/rc.pvr and create an empty file with the same location and the same name. This is the script that loads the graphics library, so we don't want it to do that.
    2.3. Restart the board. When you log in and check /proc/modules, there should be no module named 'pvrsrvkm' there.

    Check how the Weston background looks. You can also run some Weston examples that don't need OpenGL, e.g. 'weston-flower' and see how those look on the screen.

    By the way, you mentioned before that in Yocto 1.6 the default pixel size is 24 bits (RGB666) while in Yocto 2.0 it is 32 bits (RGB888). Where did you see this?

    Regards,
    Georgi
  • In reply to Georgi:

    Hello Georgi,

    1. In the weston.ini file default no section, we added to test, as you suggested i kept only below lines,

    [output]
    name=LVDS-1
    mode=current

    2.
    2.1. I checked the file Check the file /etc/defaults/weston, it contains below lines in that there is no part --use-v4l2,
    #!/bin/sh

    OPTARGS="--idle-time=0"

    now i updated for testing as below
    #!/bin/sh
    OPTARGS="--use-v4l2 --idle-time=0"

    2.2 There is no folder named /proc/modules i checked /proc folder there is a module called pvr, after making the modification as you suggested that is, renaming the /etc/init.d/rc.pvr and added new empty file with the same name, inside the /proc folder the pvr module no more exist after restart.

    After doing all the changes and reset still the behavior not changed, issue still existed and weston-flower example also not coming properly.


    By the way, you mentioned before that in Yocto 1.6 the default pixel size is 24 bits (RGB666) while in Yocto 2.0 it is 32 bits (RGB888). Where did you see this?
    --> before setting the boot argument video=LVDS-1:1280x800-16@60, we tested the command fbset command. The response is as below for yocto 1.6

    mode "1280x800-0"
    # D: 0.000 MHz, H: 0.000 kHz, V: 0.000 Hz
    geometry 1280 800 1280 800 16
    timings 0 0 0 0 0 0 0
    accel true
    rgba 5/11,6/5,5/0,0/0
    endmode

    and for yocto 2.0
    rgba displayed with the 888.

    Based on that we thought its rgb888.

    Regards,
    Charan
  • In reply to Charan K S:

    Hi Charan,

    At the beginning of this thread you had linked a file where you were showing some code changes that you made to panel-simple.c. There you had specified 8 bits per pixel and RGB888 format. This is probably why you are seeing that in fbset.

    Why did you make those changes? I am looking at my Yocto 2.0 build environment and panel-simple.c there has a definition for the hannstar panel, specifying 6 bits per pixel and RGB666 format. I think this is the format that you should use. Do you try to run it this way?

    Regards,
    Georgi
  • In reply to Georgi:

    Hello Georgi,

    we tried by making 666 as well as 888 format, currently we are using the RGB666 format only, I attached the screen shot of the  panel-simple.c which we made changes. { we tested all your above thread suggestion related to weston.ini and weston are tested in RGB666 format}.

     

    Regards,

    Charan

  • In reply to Charan K S:

    Hello Georgi,

    Updates:
    In order make sure whether the timing parameter we updated for hannstar display in panel-simple.c is working or not, we made the .clock value to 0 and also .vrefresh to 0.
    We expected that since the frequency and refresh value is zero, display should not come, but there is effect on the display its coming as previous.
    Do we miss something here?
    why if we change the display timings its not reflecting?

    Do we have any command to test what is the clock frequency, refresh rate, vsync hsync etc during run time?

    Regards,
    Charan
  • In reply to Charan K S:

    Hi Charan,

    Even if you specify zeros for some parameters the driver will ignore them if they are not valid and will make sure to specify valid values to the hardware.

    I am not sure what else I can suggest, other than troubleshooting this at the driver level and seeing what the differences are between the way the driver configures the hardware in Yocto 1.6 and Yocto 2.0.

    To check the various timing parameters from the command line you can use modetest -
    modetest -M rcar-du

    To troubleshoot the driver, just trace the display timing values in the function rcar_du_crtc_set_display_timing(), located in -
    drivers/gpu/drm/rcar-du/rcar_du_crtc.c.
    There must be some difference in those values between Yocto 1.6 and 2.0 that explains the display issue you are seeing.

    Regards,
    Georgi
  • Charan,

    Have you experienced success with your display?

    Mike Clements
    RenesasRulz Moderator
  • In reply to Mike Clements:

    Hi Mike,

    We are not yet able to solve the display issue.

    Regards,
    Charan