Display not working on Pi 4G-IOT

jonsmirl · Published in 2018-4-26 20:40:50

Edited by jonsmirl at 2018-4-26 20:43

MT6737 does not have native HDMI support. The HDMI support is from an external LT8912B MIPI DSI to HDMI converter chip. If you look in the source, ./misc/mediatek/hdmi_runyee/lt8912b, there is clearly not a full driver for it.

Google for LP8912B and I found this hit..
https://gist.github.com/kj77/f7c46a04daac45b802268fcc13272eaa

                     qcom,mdss_dsi_lt8912_480p_video {
                              qcom,mdss-dsi-panel-name = "lt8912 480p video mode dsi panel";
                              qcom,mdss-dsi-panel-type = "dsi_video_mode";
                              qcom,mdss-dsi-panel-destination = "display_1";

So it appears that the lp8912 is support somewhere inside the qualcomm mdss-dsi driver. That driver is open source...
https://android.googlesource.com ... ers/video/msm/mdss/

So somewhere in that source should be the needed code. If it is not in that source, try later versions of the qcom kernel.

bspi · Published in 2018-6-1 21:25:12

So no solution so far ?

AlexFBG · Published in 2018-6-2 11:48:52

Edited by AlexFBG at 2018-6-2 12:02

You must edit the kernel source files:

bd6737m_35g_b_m0.dts - 48Hz to 60Hz

//orangepi hdmi
&i2c2{
lt8912b@48 { /<---- 48Hz mode
compatible = "mediatek,lt8912b";
reg = <0x48>; /<-----48Hz mode
};

Copy code

In lt8912b.c - 720X1280 to 1280X720 mode

//#define LT8912B_SELF_TEST_MODE_1920X1080
//#define LT8912B_SELF_TEST_MODE_1366X768
//#define LT8912B_SELF_TEST_MODE_1280X720
#define LT8912B_SELF_TEST_MODE_720X1280 /Default screen resolution.

Copy code

You may need to edit other source files and recompile the kernel.

jonsmirl · Published in 2018-6-3 01:57:35

Edited by jonsmirl at 2018-6-3 02:06

That <0x48> is not setting the refresh frequency. That is the I2C address of the chip. You don't want to change that.

Those are not the correct changes to fix the problem.
I believe there is a driver for the lt8912 buried inside the qualcomm msm driver somewhere...
https://android.googlesource.com ... rs/video/fbdev/msm/

qcom,mdss_dsi_lt8912_1080p_video {

qcom,mdss-dsi-panel-name = "lt8912 1080p video mode dsi panel";

qcom,mdss-dsi-panel-type = "dsi_video_mode";

qcom,mdss-dsi-panel-destination = "display_1";

qcom,mdss-dsi-color-order = "rgb_swap_rgb";

qcom,mdss-dsi-lane-map = "lane_map_0123";

qcom,mdss-dsi-panel-framerate = <0x3c>;

qcom,mdss-dsi-virtual-channel-id = <0x0>;

qcom,mdss-dsi-stream = <0x0>;

qcom,mdss-dsi-panel-width = <0x780>;

qcom,mdss-dsi-panel-height = <0x438>;

qcom,mdss-dsi-h-front-porch = <0x58>;

qcom,mdss-dsi-h-back-porch = <0x94>;

qcom,mdss-dsi-h-pulse-width = <0x2c>;

qcom,mdss-dsi-h-sync-skew = <0x0>;

qcom,mdss-dsi-v-back-porch = <0x24>;

qcom,mdss-dsi-v-front-porch = <0x4>;

qcom,mdss-dsi-v-pulse-width = <0x5>;

qcom,mdss-dsi-h-left-border = <0x0>;

qcom,mdss-dsi-h-right-border = <0x0>;

qcom,mdss-dsi-v-top-border = <0x0>;

qcom,mdss-dsi-v-bottom-border = <0x0>;

qcom,mdss-dsi-bpp = <0x18>;

qcom,mdss-dsi-underflow-color = <0xff>;

qcom,mdss-dsi-border-color = <0x0>;

qcom,mdss-dsi-on-command = [05 01 00 00 a0 00 02 11 00 05 01 00 00 a0 00 02 29 00];

qcom,mdss-dsi-off-command = [05 01 00 00 78 00 02 28 00 05 01 00 00 78 00 02 10 00];

qcom,mdss-dsi-on-command-state = "dsi_lp_mode";

qcom,mdss-dsi-off-command-state = "dsi_lp_mode";

qcom,mdss-dsi-h-sync-pulse = <0x0>;

qcom,mdss-dsi-traffic-mode = "non_burst_sync_event";

qcom,mdss-dsi-bllp-eof-power-mode;

qcom,mdss-dsi-bllp-power-mode;

qcom,mdss-dsi-lane-0-state;

qcom,mdss-dsi-lane-1-state;

qcom,mdss-dsi-panel-timings-phy-v2 = <0x231e0809 0x50304a0 0x231e0809 0x50304a0 0x231e0809 0x50304a0 0x231e0809 0x50304a0 0x231a0809 0x50304a0>;

qcom,mdss-dsi-panel-timings = <0xe6382600 0x686c2a3a 0x2c030400>;

qcom,mdss-dsi-t-clk-post = <0x2>;

qcom,mdss-dsi-t-clk-pre = <0x2b>;

qcom,mdss-dsi-dma-trigger = "trigger_sw";

qcom,mdss-dsi-mdp-trigger = "none";

qcom,mdss-dsi-reset-sequence = <0x1 0x14 0x0 0x2 0x1 0x14>;

qcom,mdss-dsi-post-init-delay = <0x1>;

qcom,mdss-dsi-force-clock-lane-hs;

};

AlexFBG · Published in 2018-6-3 13:45:41

jonsmirl replied at 2018-6-3 01:57
That is not setting the refresh frequency. That is the I2C address of the chip. You don't want to c ...

It's true. How build kernel without compile all system?

bspi · Published in 2018-6-16 13:51:32

Hi @admin

When Linux for Orange pi 4G-IoT will be ready ?

It pass 2 month since last time ?

5n31d3R · Published in 2018-7-11 21:50:07

Hallo! I'm also can't connect my 4G nowhere, I had tried 5 monitors, but the result was negative( And I understood, there is no solution for this big trouble?

Yassir18 · Published in 2018-7-30 04:59:19

hello i'm from spain and i got the same problem with this board 48hz hdmi is a big problem so what ive do is connect the board in to the PC using a abd and Vysor and the board works fine a little bit of lag cause the conection of adb usb is not so good

my idea was conect this board in my car with the kenwood ddx5025bt cause it got the option of mhl and i control the board using my radio screen but the problem is that no signal of video i tryed in a 3 different monitors included televisor 4k samsung unfrutunatly no result so the last solution is a linux or a windows for this board if anyone make work hdmi 50/60hz in this board let me know please

admin · Published in 2018-8-1 10:58:45

bspi replied at 2018-6-16 13:51
Hi @admin

When Linux for Orange pi 4G-IoT will be ready ?

So sorry for my late respond. But bad news is that i also do not have any information about Linux status. Sorry cannot tell you about the release date.

jafero · Published in 2018-8-9 21:34:18

Hi HDMI dont work in new android version 6 and 8 posted in downloads
only work with vysor

i open orangepi 4g to check with vysor
connect 5v power and usb togheter

Display not working on Pi 4G-IOT

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