This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

PROCESSOR-SDK-AM62X: Display Flickering on SK-AM62x-LP with dss_display_share in OSPI NAND Mode

Part Number: PROCESSOR-SDK-AM62X
Other Parts Discussed in Thread: UNIFLASH, AM62P

Tool/software:

Hello TI Community,

I am encountering a display flickering issue on the SK-AM62x-LP board when booting in OSPI NAND mode after integrating the dss_display_share feature to share the DSS between the MCU (R5F) and Linux (A53). The display shows both the tell-tale (from R5F firmware) and the Linux default launcher (from SD card rootfs), but it flickers continuously.

Without this app, the display is stable. Below are the details of my setup, modifications, and the issue.

Board: SK-AM62x-LP

SDK Version:mcu_plus_sdk_am62x_11_00_00_16,ti-processor-sdk-linux-am62xx-evm-11.00.09.04

Boot Mode: OSPI NAND

Display Configuration: k3-am62-lp-sk-microtips-mf101hie-panel

Flashing Process:

  1. UART with uart_uniflash.py,

  2. Added dss_display_share.release.appimage.hs_fs to OSPI NAND at offset 0xA00000.

  3. Used SD card with Linux image tisdk-default-image-am62xx-lp-evm-11.00.09.04.rootfs.wic.xz

Modifications Made

To enable dss_display_share on the SK-AM62x-LP, I made the following changes to the SDK:

  • Edited default_sbl_ospi_nand_linux_hs_fs.cfg:
    Added the following line to include the dss_display_share application image:

    --file=../../examples/drivers/dss/dss_display_share/am62x-sk/r5fss0-0_freertos/ti-arm-clang/dss_display_share.release.appimage.hs_fs --operation=flash --flash-offset=0xA00000
  • Edited makefile.am62x.r5f.ti-arm-clang:
    Added DSS and FVID2 drivers to the R5F build

  • Edited am62x/dss_soc.h:

    Modified to route DSS0 interrupts to R5F core

  • Edited makefile.am62x:

    Added dss_display_share build target for R5F

  • Edited Device Tree Files:

    Modified k3-am62-main.dtsi and 

    k3-am62x-sk-common.dtsi

    
    

Issue Details

The display flickering occurs only when the dss_display_share application is flashed

When dss_display_share is flashed, the display shows both the R5F tell-tale and the Linux default launcher, indicating partial functionality of DSS sharing, but it flickers continuously.

  • Hi,

    I have a few questions: Do you mean AM62x-lp or AM62P-lp?
    AM62x does not have MCU(R5F) core rather MCU(M4) core, AM62P has a MCU(R5F core).
    I believe the dss_display_share example you are referring to is mentioned and validated for AM62P and not for AM62x.

  • Hi,

    Thank you for your response and for pointing out the potential confusion between AM62x and AM62P. After reviewing the boot log and the TI MCU+ SDK documentation for AM62x (version 11.00.00.16, link), I’d like to clarify my setup and address your questions regarding the flickering issue with the dss_display_share application.

    1.Board and Core Clarification: I am using the SK-AM62x-LP board with the AM62x processor, which includes both an M4F core (m4f0-0) and an R5F core (r5f0-0) along with the A53 core (a530-0) for Linux. The boot log confirms this:

    Log:-

    SYSFW Firmware Version 11.0.7--v11.00.07 (Fancy Rat)
    SYSFW Firmware revision 0xb
    SYSFW ABI revision 4.0

    [BOOTLOADER_PROFILE] Boot Media : FLASH
    [BOOTLOADER_PROFILE] Boot Media Clock : 166.667 MHz
    [BOOTLOADER_PROFILE] Boot Image Size : 1857 KB
    [BOOTLOADER_PROFILE] Cores present :
    hsm-m4f0-0
    r5f0-0
    a530-0

    The SDK documentation (AM62x Device Description) also confirms the presence of R5F and M4F cores in the AM62x.https://software-dl.ti.com/mcu-plus-sdk/esd/AM62X/11_00_00_16/exports/docs/api_guide_am62x/index.html

    2. dss_display_share Example Clarification:

    I need to clarify that the MCU+ SDK 11.00.00.16.does not provide a dss_display_share example specifically for AM62x under examples/drivers/dss/ .

    I have made modifications to make it work on AM62x. Changes done are mentioned in the ticket.

    3.Flickering Issue: The display flickering occurs only when flashing the dss_display_share.release.appimage.hs_fs to OSPI NAND at offset 0xA00000.

    Without this app, the display is stable, indicating the issue is tied to the adapted DSS sharing implementation.

  • Hi Aniruth,
    In MCU domain, there is only M4F core, R5 is handling device management in WKUP domain.
    I understand you are trying to port this example from AM62P to AM62x, but currently we cannot support this usecase.

  • Hi Divyansh,

    Thank you for the clarification regarding the AM62x architecture and the role of the R5F core in the WKUP domain for device management (DM) and the M4F core in the MCU domain. 

    I understand that this use case is not officially supported, but given our need to use the R5F core for early display (e.g., tell-tale display) and device management on the SK-AM62x-LP, alongside the A53 core for Linux, to achieve DSS sharing, any guidance on adapting the example,or alternative approaches for AM62x would be greatly appreciated. I can test suggested configurations, apply patches, or provide additional logs.

  • Hi Aniruth,
    Unfortunately, we are unable to support the use of AM62x for display display sharing in the manner you described. The current software architecture and design limitations prevent us from providing guidance on adapting the example for this specific use case.

  • Ok.I have specific doubts about configuring LVDS timing parameters for the AM62x with our LVDS panel [1920x1200 k3-am62-lp-sk-microtips-mf101hie-panel ]. Incorrect timings may be contributing to the flickering. Could you provide:

    Recommended LVDS timing parameters

  • Hi,
    Timing parameters for k3-am62-lp-sk-microtips-mf101hie-panel are specified under corresponding panel descriptor inside panel-simple.c.
    Please create a separate thread for further information.