LCD GUI flickering and displace vertically when using SPI FLASH/PSRAM Quad mode

[migmel]

Hello guys,
I have tested a GUI application using an ESP32-S3 based custom board with 8MB external SPI PSRAM working in Octal mode. Now the same application when is tested in the same condition but using 8 MB external SPI PSRAM working in Quad mode, the LCD image start flickering and displace vertically.
GUI is managed with LVGL.
Can anybody point at what/where might be the problem when a this kind of fail happens?
Thank you

[MicroController]

Just a guess, but could you be having timing issues since you basically cut the PSRAM's bandwidth by 50%?

[migmel]

Thank you for your reply,
Yes, I suppose it has to be related with timing or memory. In this case how could this be overcome?
I have realized that after changing to quad mode, some tasks started to have stack overflow and had to add more stack memory to them.
Should I reduce the refresh frequency in the LVGL manager task ?

[MicroController]

after changing to quad mode, some tasks started to have stack overflow and had to add more stack memory to them.

That's interesting.
Have you checked if the ESP actually detects the PSRAM in quad mode?

[migmel]

Yes, FLASH and PSRAM are correctly detected.
It seemed weird to me at the moment, but then I increased the stack memory and the problem was solved. Made me think of some memory problem but I did not get any error at runtime, so ruled that out