ESP32S3 RGB LCD refresh while writing to SPI flash

[marbalon]

Hi,

I have a project with ESP32S3 + LCD 800x480 over RGB + 8MByte PSRAM. ESP-IDF 5.0.

I had some problems with rotation but I found a combination where it is working, so there is only one hardware problem left:

How to keep LCD refreshed when SPI flash is written?

In manuconfig I marked all SPI, GDMA, and LCD ISR to be placed in IRAM, but nothing helped. Every time I try to write/erase even a small chunk of SPI flash LCD has some problems and LCD content is scrolling - see video below.

https://photos.app.goo.gl/ADEsUmmQ48gAaNz4A

Any idea how to keep LCD driver working when SPI flash writes need to be called in the background?