Qcomlt-5.2 sda845 enabling dsi0 and dsi1 together

hi,

I want to enable both dsi0-Panel0 and dsi1-panel1 together. Below is my changes , but no data on both the displays. please suggest

When tested individually dsi0 and dsi1 data comes properly in the display.

similar changes done earlier for qcom-apq8064 had worked for dsi0 and dsi1

regards,
vinaysimha

Hi vinaysimha,
Did you successfully add both dsi on sda845c?
I have another 845 dev kit “sdm845”, it looks like the dtsi files I have modified are different.
Also, on sda845c hardware design, the DSI0 alwars connects to a bridge LT9611.
Is it possible to pass through this bridge and output from DSI0 directly?

Thanks,
Henry

Dual DSI works in sda845.

Bypassing i am not sure. It depends on the h/w design. If dsi0 lanes going external to expansion header it is possible.

regards,
vinaysimha

Do you mean the Dual DSI of your design works to output via HDMI Type-A interface in RB3?


From RB3 H/W design, DSI0 is no room to bypass from LT9611.
Do you know if the MIPI DCS read command is able to work in your case?

Thanks,
Henry

henry,

In our design, DSI0 and DSI1 is going to an header.

In RB3 if DSI0 used for dsi2hdmi, it is not possible to bypass. if similar switch would had given for DSI0 then DSI0 could be used for panels/bridges.

I have not verified the DCS read command.

regards,
vinaysimha

Hi Vinaysimha,
Okay. So you are not using RB3.
Actually, I have been developing my function on SDM845 from Intrinsic but it ends up with the DCS read command not supported on latest release. The Ln0 of DSI0 keeps low and goes timeout after DDIC returns BTA with data. They said this issue requires to modify code in Bootloader and kernel images and they won’t fix it until I purchase their service package costing 1200 USD.
I think DCS read should be very basic function if they claim MIPI DSI v1.2 is supported.
So now, I am looking for another solution for it.
May I know which platform did you purchase?

Thanks,
Henry

henry,

Try the latest release Linaro Releases or
Linaro Releases

What is your requirement? Dual DSI or bridge ? Why the DCS read is necessary ?

regards,
vinaysimha

vinaysimha,
Thanks for the information.
I every bought some kits from Inforce but they seldom reply my question regarding these kits. I’d try it if their 845c supports DCS read command.

I use dual DSI directly and the reason I need Read function is because I have to get some information and data from DDIC for my implementation.
Can you help me to check if DCS read command is working on Inforce 845c if you are available?
Thank you.

BRs,
Henry

henry,

dcs read command works in 5.4.41 kernel 20.02 release.
please explain on “data from DDIC for my implementation”

regards,
vinaysimha

vinaysimha,
That’s great to know the MIPI DCS read command working on this version of 845.

I implement an APP to read data from DDIC to know some DDIC information, for example panel status/DBV/internal ID values. This is a customized APP for some DDIC manufactures.

I vary vary thank you for this great information.

BRs,
Henry

henry,

fyi,
i had read the panel 0xDA (Read ID1) got the expected read-back by dcs read.

regards,
vinaysimha

vinaysimha,
I found mainline kernel is a GKI, so how do you run a DCS read command with existing kernel fd? or you create a kernel module for it?

Thanks,
Henry

How did you try to run earlier and checked dcs read not working?

I tried by mipi_dsi_dcs_read command, refer panel-samsung-s6e8aa0.c, panel-sony-acx424akp.c

regards,
vinaysimha

I read it by a fd I implemented, but that fd still calls to qualcom mdss driver mdss_dsi_cmd_dma_rx in the end.
And I found the issue by the scope that shows mdss core doesn’t response to any BTA signal from DDIC at all.
image006
They said this issue needs to be fixed by BL and BOOT upgrade.

Do you use mainline GKI on your Inforce 6701?

BRs,
Henry

The problem is in the implementation of fd driver, the 5.x kernel used drm, implement the fd using mipi_dsi_dcs_read by referring panel-samsung-s6e8aa0.c, panel-sony-acx424akp.c panel drivers.

regards,
vinaysimha