Lv_port_stm32f769_disco : TFT_NO_TEARING gives a garbage screen when activated

Bug (archived)
1

Description

I used the tft driver available here:
https://github.com/lvgl/lv_port_stm32f769_disc
It’s not working until I set the TFT_NO_TEARING to 0. What’s the purpose of the TFT_NO_TEARING option and why do I have a screen full of miscalenous pixels when TFT_NO_TEARING is set to 1, but a correct display when TFT_NO_TEARING is set to 0 ?

What MCU/Processor/Board and compiler are you using?

STM32F769I-Disco board

What do you experience?

Random pixels with different colors but no figures are displayed if TFT_NO_TEARING is set to 1 (default setting). Correct display if I change this setting to 0.

What do you expect?

Code to reproduce

Add a code snippet to reproduce the issue in the simulator. It should contain only the relevant code which can be compiled. Bug reports without code snippets or with erroneous code snippets will not be reviewed.

This is working:

#define TFT_NO_TEARING  0    /*1: no tearing but slower*/

This is not:

#define TFT_NO_TEARING  1    /*1: no tearing but slower*/

Screenshot and/or video

This is what I get with the default setting:

image
image1302×978 788 KB

Display is correct with TFT_NO_TEARING set to 0

2

Hi,

I’ve tried it and found that my working directory was dirty. Maybe a half ready code was pushed…

I updated to latest LVGL and it works for me.

3

Hi, I am trying to develop on the STM32F769I Discovery board.
I see the demo from kisvegabor works, however the code provided is with an older lvgl version. Also the IOC file is not included, which makes it extremely difficult guessing the board settings that were used for the demo.
Is there a plan to get the demo upgraded and providing the IOC file?
Thanks