@ferite
Did you solve it?
@gacktex suggests you should disable touch so you don’t get i2c stuck.
Today i received two 7" LCD from different makers, both with FT2506, one (the cheapest) worked, and the other have trouble with the backlight, even with touch disabled. But both touch works fine.
@gacktex, in your post you comment this " GPIO3-C7 of the MIPI-DSI interface is not powered on by default, resulting in no response from the slave. . . ."
Can you elaborate on what you did , maybe this can help?
The craziest thing is the i2cdetect behavior
7" panel that works:
sudo i2cdetect -y 3
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
10: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f
20: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f
30: 30 31 32 33 34 35 36 37 UU 39 3a 3b 3c 3d 3e 3f
40: 40 41 42 43 44 UU 46 47 48 49 4a 4b 4c 4d 4e 4f
50: 50 51 52 53 54 55 56 57 58 59 5a 5b 5c 5d 5e 5f
60: 60 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f
70: 70 71 72 73 74 75 76 77
7" panel that does not turn on the backlight:
sudo i2cdetect -y 3
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- UU -- -- -- -- -- -- --
40: -- -- -- -- -- UU -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
rock@rock3a:~$ dmesg|grep mcu
[ 0.965190] rockpi-mcu: rockpi_mcu_probe: address = 0x45
[ 0.965232] rockpi-mcu: send_cmds: 80
[ 1.017356] rockpi-mcu: init_cmd_check: recv_cmds: 0xC3
[ 1.981462] rockpi_mcu_screen_power_up
[ 1.981465] rockpi-mcu: rockpi_mcu_screen_power_up:
[ 1.981477] rockpi-mcu: send_cmds: 8500
[ 2.827651] rockpi-mcu: send_cmds: 8501
[ 3.680714] rockpi-mcu: send_cmds: 8104
[ 3.707886] rockpi-mcu: rockpi_mcu_set_bright: bright = 0xff (back light ON max)
[ 708.888963] rockpi-mcu: rockpi_mcu_set_bright: bright = 0x0 (back light OFF - idle)
[ 1158.814747] rockpi-mcu: rockpi_mcu_set_bright: bright = 0xff (touched the display and back light ON)
rock@rock3a:~$