Hello Community,
We are using Apalis IMX8QP and Apalis IMX8QM for LCD display applications, for that in the dtsi file we made some configurations according to our panel. We are able to up the LCD display and played our application on the display. This is working fine almost every time, but few times SOM getting stuck while booting, after some time booting is resuming and again stuck for sometime and this is happening for few minutes. After login i am able to send commands to SOM and playing a video using a command, in SOM terminal it showing like video playing without any issue, but the LCD display got stuck( no video is playing on the display).
I am attaching dtsi file , boot data and a video file ( it shows problem ).
Is this the custom image that you are booting?
We have built the image from Yocto project only, in that image we made panel related changes in dtsi file.
We have installed nginx and meta-webkit for browser related video playing application.(refer local.conf)
Do you see the same behaviour (booting stuck and resume) if display is not connected ?
Yes i observed the same behavior without Display also.
Please always send the device tree files in git diff format so that we can see the changes
I am attaching here a patch.txt file,
Along side, i am also attaching local.conf file for your reference
Hi @Muthyam ,
By looking at the following boot logs shared by you
20.189944] [drm:drm_atomic_helper_wait_for_dependencies] *ERROR* [CRTC:125:crtc-3] flip_done timed out
[ 30.429923] [drm:drm_atomic_helper_wait_for_dependencies] *ERROR* [CONNECTOR:151:LVDS-1] flip_done timed out
It seems to be related to drm driver (drivers/gpu/drm/drm_atomic_helper.c) page flipping which may be reated to display timings.
How often you are seeing this issue and will you be able to share the steps to reproduce?
Also, is this happening with this display only or with other display as well?
Do you have similar display from different manufacturer to further test ? This will help us to narrow down issue if it is related to display timings or not.
Hello @sahil.tx,
We are observed that issue very frequently like once in 30 times( power cycle reset or reboot), later we found that in overlays (i.e in /boot folder) it default connected to hdmi, then we commented that overlay, from then the issue occurring frequency got reduced, but it is still present like once 80 times.
We tried this with two different displays, one display is from AUO and other one from SEC make.
But for the both displays, we are using same timings in dtsi file. There is no specific steps to reproduce the issue, do power cycle reset or system reboot continuously.
I am attaching panel timings of those two displays and patch file for dtsi modifications.
Hi @Muthyam ,
Since the issue is not observed with default toradex image, you need to re-check the customization you did especially related to display timings.
The patch shared does not match with the display setting provided.
eg. you have set 1920x1080 as resolution which is not in accordance to the timings in the datasheet
Also, there are misconfiguration in the device tree,
eg you have set panel-timings twice with different timings, how you are making sure which one will apply?
Hello @sahil.tx ,
Someone from Toradex Support team helped us with panel-timings way back. We gave him the Data Sheet of AUO Panel, in reply he gave us the panel-timings, we included them in our image.
We don’t know the formulae to find these parameters
clock-frequency = <148500000>;
hactive = <1920>;
vactive = <1080>;
hback-porch = <60>;
hfront-porch = <60>;
vback-porch = <20>;
vfront-porch = <20>;
hsync-len = <20>;
vsync-len = <5>;
hsync-active = <0>;
vsync-active = <0>;
pixelclk-active = <0>;
Can you help us to find these parameters, or provide the correct configuarations according AEO display datasheet.
Thank You.
Muthyam D.
Hi @Muthyam,
You dont need formulas and no need to calculate values as this information should be provided in the datasheet.
You can refer to this article for understanding various parameters related to display timings and check their value to be used in your display datasheet.
