How to get HDMI packet data

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX2
1

Hello everyone.

I want to pass HDMI2.0 compliance test.
so I tried to check HDMI packet data(HDMI specification ver1.4 Table5-8 Packet Types’s data) using devmem2 beforehand.
I succeed check following packets.

  • Audio Clock Regeneration
  • General Control
  • Vendor-Specific InfoFrame
  • AVI InfoFrame
  • Audio InfoFrame
    But others packet is not found .

How to check others packet data in TX2 developer board ?
Especially I want to read following packet data.

  • Null (5.3.2 in HDMI 1.4 specifications )
  • Audio Sample (5.3.4 in HDMI 1.4 specifications )
  • ACP (5.3.7 in HDMI 1.4 specifications )
  • ISRC1 (5.3.8 in HDMI 1.4 specifications )
  • ISRC2 (5.3.9 in HDMI 1.4 specifications )

thank you.

2

yasuhiro_yamamoto,

May I ask how do you use devmem2 to read the such data? Do you see any guidance in our document?

3

WayneWWW

Thank you for reply.

Which is the document you say?
I looked through TRM( especially chapter 25 ).
Please tell me if I make any mistakes.

[How to use devmem2 ]
I used devmem2 in the following steps.
*System is L4T Sample Root File System 28.2.

  1. Connect TX2 developer board(HDMI port) and LCD monitor.
  2. Display ubuntu desktop screen.
  3. Sound a test sound source.
    == Read packet data from TX2 ==
  4. Use my customized devmem2.

e.g. SOR_NV_PDISP_SOR_HDMI_AVI_INFOFRAME

#define MAP_SIZE 4096UL
#define MAP_MASK (MAP_SIZE - 1)
#define BASE_ADDR 0x15540000
#define AVI_INFO_OFFSET_ADDR 0x288
#define AVI_INFO_LEN 0x14
    
    ......
 fd = open("/dev/mem", O_RDWR | O_SYNC)) 
 map_base = mmap(0, MAP_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, BASE_ADDR & ~MAP_MASK);

 for(offset = AVI_INFO_OFFSET_ADDR ; offset < AVI_INFO_OFFSET_ADDR+AVI_INFO_LEN;){
       alignment = (map_base + offset) % 8;
       addr = map_base + map_base + offset - alignment;
       memcpy(&reg_data,addr,8);
       printf("%x ",reg_data);
       offset = offset + 4;
 }
4

yasuhiro_yamamoto,

Sorry that I am not familiar with the full process of HDMI 2.0 compliance test. Is getting HDMI packet through software a necessary instruction?

In fact, latest rel-28.2.1 should be able to pass HDMI compliance test but with some condition (no HDCP, no YUV mode)

5

Hello WayneWWW.

I’m not saying that HDMI compliance test does not pass.I got HDMI packet data using protocol analyzer.

This question purpose is following
When HDMI compliance test(e.g Test ID 7-19 Packet Types) failed, I want to know what is TX2’s output packet settings wrong.

6

yasuhiro_yamamoto,

Seems no such usecase in Nvidia before. If we failed to pass HDMI compliance test, it is usually to use HDMI analyzer.

7

Thank you for your response.

OK.
I will use HDMI protocol analyzer when the test is failed.