I need to enable GDMA in esp32c3 but I get descriptor error, did I fill descriptor correctly?

[Abdulrhman_Battikh]

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1. #include "gdma_struct.h"
2. typedef struct dma_link {
3.     struct {
4.         uint32_t size :    12;      //the size of buf, must be able to be divisible by 4
5.         uint32_t length:   12;      //in link,
6.         uint32_t reversed: 6;       //reversed
7.         uint32_t eof:      1;       //if this dma link is the last one, you shoule set this bit 1.      
8.         uint32_t owner:    1;       //the owner of buf, bit 1 : DMA, bit 0 : CPU.
9.     } des;
10.     uint8_t *buf;                   //the pointer of buf
11.     struct dma_link *pnext;    //point to the next dma linke, if this link is the last one, set it NULL.
12. } dma_link_t;
13.  
14. dma_link_t dma_trans;
15. dma_link_t dma_receive;
16.  
17. uint8_t transmit[5]="hello";
18. uint8_t receive[5]={0};
19. void app_main()
20. {
21. //load outlink
22. dma_trans.des.size = 0;
23. dma_trans.des.length = 5;
24. dma_trans.des.eof = 1;
25. dma_trans.des.owner = 1;
26. dma_trans.buf = transmit;
27. dma_trans.pnext = NULL;
28. //load inlink
29. dma_receive.des.size = 5;
30. dma_receive.des.length = 0;
31. dma_receive.des.eof = 1;
32. dma_receive.des.owner = 1;
33. dma_receive.buf = receive;
34. dma_receive.pnext = NULL;
35.  
36. //reset GDMA's transmit channel
37. GDMA.channel[0].out.out_conf0.out_rst = 1;
38. GDMA.channel[0].out.out_conf0.out_rst = 0;
39. //reset GDMA's receive channel
40. GDMA.channel[0].in.in_conf0.in_rst = 1;
41. GDMA.channel[0].in.in_conf0.in_rst = 0;
42. //address of the transmit descriptor  
43. GDMA.channel[0].out.out_link.addr = (((uint32_t)&(dma_trans)) & (0xfffff << 0));
44. //address of the receive descriptor
45. GDMA.channel[0].in.in_link.addr = (((uint32_t)&(dma_receive)) & (0xfffff << 0));
46. //enable memory to memory transfer
47. GDMA.channel[0].in.in_conf0.mem_trans_en = 1;
48. //enable transmit channel
49. GDMA.channel[0].out.out_link.start = 1;
50. //enable receive channel
51. GDMA.channel[0].in.in_link.start = 1;
52. }
53.  

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[ESP_Sprite]

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dma_trans.des.size = 0;

Try setting this to the same as .des.length, rounded to the next multiple of 4.

[Abdulrhman_Battikh]

I set dma_trans.des.size but I did't get any response, but I read in technical reference for esp32c3 in system and memory chapter the following:
""when accessing a memory via GDMA, a corresponding access permission is nedded, otherwisethis access may fail""
also:
""All of the internal memories are managed by Permission Control module. An internal memory can only be accessed
when it is allowed by Permission Control, then the internal memory can be available to the CPU""
in the default mode, is access permission enabled for GDMA?
is there another reason for my problem?